test: adopt native-validated 24-target probe layout

Horizontal y=56 and vertical x=38 through box 1, normal coordinates [12.5..26.125] (root128 physical). Nearest-ACTIVE mapping with deterministic tie rule (distance, finer level, smaller j, smaller i), duplicate-cell rejection, stored centers and displacements. Replaces my earlier offsets, which mapped two target pairs to the same U128 cell. U512 spacing 128/512 and root step r -> U512 step 4r unchanged. Tests: 24 unique cells per case, nested 3 L0 + 5 L1 + 4 L2 per transect, U128 max displacement 0.625. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
test: signed interface-probe trace diagnostic (--probe-trace)
2026-10-19 03:13:43 +00:00 · 2026-10-19 03:11:48 +00:00 · 2026-10-19 02:52:20 +00:00 · 2026-10-19 02:14:23 +00:00 · 2026-10-19 01:15:59 +00:00 · 2026-10-19 01:14:54 +00:00
160 changed files with 5505 additions and 10199 deletions
@@ -112,21 +112,20 @@ from CelerisLab.lbm.refinement_stepper import FixedPatchStepper
 cfg = LBMConfig(nx=32, ny=24, viscosity=.1)
 body = SimObject(0, geometry=CircleGeometry(16.0, 12.0, 2.15), center=(16.0, 12.0), radius=2.15,
                 surface_actuation=SurfaceActuation(0.7, 0.85, 0.002))  # angle, half-width, speed
-with CudaContext(0) as ctx, FixedPatchStepper(cfg, context=ctx, refinements=[(8, 6, 24, 18)],
-                                              level_blocks=[None, (16, 20)],
-                                              level_objects=[(), (body,)]) as run:
+with CudaContext(0) as ctx, FixedPatchStepper(cfg, (8, 6, 24, 18), context=ctx,
+                                              fine_objects=[body], fine_block=(16, 20)) as run:
    rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]
    # (9, ny, nx) postcollision populations per level; non-leaf cells are discarded.
-    run.initialize(np.broadcast_to(rest, (9, *run.hierarchy.pairs[0].coarse_shape)),
-                   np.broadcast_to(rest, (9, *run.hierarchy.pairs[0].fine_shape)))
+    run.initialize(np.broadcast_to(rest, (9, *run.patch.coarse_shape)),
+                   np.broadcast_to(rest, (9, *run.patch.fine_shape)))
    run.step(128)                      # coarse steps; fine level takes two per step
    coarse_g, fine_g = run.download()  # NaN on covered, ghost and solid cells
 ```

 Scope and limits:
 - The examples below use D2Q9, SRT, FP32, double buffer, unshifted, no LES or
-  forcing. Fixed 2:1 hierarchies use level lists of arbitrary depth; two- and
-  three-level examples below use that same constructor.
+  forcing. Fixed 2:1 hierarchies can use level lists of arbitrary depth; the
+  legacy two/three-level forms are shown below.
 - `coarse_boundary="periodic"` (default) or `"slot_reservoir"` (bottom slot, top
  reservoir; patch needs `y0 >= 4`, `y1 <= ny-4`). Periodic mode ignores the wall/slot config fields.
 - Object centers/radii use the coarse **cell-edge** frame (cell `I` spans `[I, I+1)`),
@@ -134,51 +133,50 @@ Scope and limits:
 - Bodies must be stationary circles whose whole boundary stencil lies in the fine
  active region, clear of the coarse/fine transfer cells; violations are rejected
  before any GPU allocation.
- `level_blocks=[None, (by, bx)]` stores the fine level in fixed-size blocks; `by`/`bx` must
+- `fine_block=(by, bx)` stores the fine level in fixed-size blocks; `by`/`bx` must
  divide the WHOLE fine allocation, i.e. `2*(y1-y0)+8` by `2*(x1-x0)+8` including the
  four-cell ghost band. It gives results identical to dense storage and is
  infrastructure for future block AMR, not a speedup.
 - Several regions: pass a sequence of `(x0, y0, x1, y1)` rectangles as
-  `refinements[0]`, with both levels blocked (`level_blocks`). Transfers are built once
+  `bounds`, with both `fine_block` and `base_block`. Transfers are built once
  from their union; adjacent, overlapping and concave unions are accepted when
  their actual dependencies close. There is no fixed rectangle-gap rule.
  The fine level is then one level-wide grid `(2*ny, 2*nx)`:
-  `run.hierarchy.pairs[0].fine_shape` gives it, `initialize`/`download` use it, and only the
+  `run.patch.fine_shape` gives it, `initialize`/`download` use it, and only the
  grid-aligned tiles intersecting the union plus its four-cell ghost band are stored.
  Block sizes must divide the level-wide grid; rectangle edges need not align
-  with tiles. Order of rectangles does not matter. L1 bodies/Jets (`level_objects[1]`/`level_jets[1]`) work
+  with tiles. Order of rectangles does not matter. `fine_objects`/`jets` work
  as for one patch: each circle (same coarse cell-edge frame) must lie wholly
  inside the union's active region with
  its boundary stencil clear of transfer cells; a jet may not select links of two
  different bodies, even across regions. Wall-touching patches remain unsupported.
-  For nesting, add further `refinements` entries as shown below.
+  For nesting, use the level lists or legacy child forms below.

  ```python
  cfg = LBMConfig(nx=32, ny=16, viscosity=.1)
  rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]
  with CudaContext(0) as ctx, FixedPatchStepper(
-          cfg, context=ctx, refinements=[((4, 4, 12, 12), (16, 4, 24, 12))],
-          level_blocks=[(4, 4), (4, 4)]) as run:
-      run.initialize(np.broadcast_to(rest, (9, *run.hierarchy.pairs[0].coarse_shape)),
-                     np.broadcast_to(rest, (9, *run.hierarchy.pairs[0].fine_shape)))  # (9, 32, 64)
+          cfg, ((4, 4, 12, 12), (16, 4, 24, 12)), context=ctx,
+          fine_block=(4, 4), base_block=(4, 4)) as run:
+      run.initialize(np.broadcast_to(rest, (9, *run.patch.coarse_shape)),
+                     np.broadcast_to(rest, (9, *run.patch.fine_shape)))  # (9, 32, 64)
      run.step(32)
      coarse_g, fine_g = run.download()  # coarse: NaN on every covered cell;
                                         # fine: NaN on every non-ACTIVE cell
  ```
- Three-level nested windows: pass two scalar rectangles in `refinements` —
-  L1 in L0 cells, L2 in **L1 window cells** (the parent's fine grid including its
-  4-cell ghost band) — plus all three `level_blocks` entries. L2 must sit inside
-  L1's ACTIVE cells, away from L1's ghost band and transfer footprint (checked
-  before any GPU allocation). `initialize` and `download` take/return three
-  arrays; each level is NaN on its non-ACTIVE (and child-covered) cells. One
-  coarse step = 2 L1 steps = 4 L2 steps. One L1 window only in this scalar
-  chain. Optional stationary circles and Jets live on L2 via `level_objects[2]`
-  and `level_jets[2]`; L1 bodies/Jets retain their L1 meaning and must be empty
-  in this mode. All object and Jet geometry uses the **L0 edge frame**, not the
-  child bounds' L1 window frame. L2 has dx=dt=0.25, so prescribed lattice
-  velocity is unchanged. Each whole body and its BFL stencil must be inside L2
-  ACTIVE cells, outside the transfer footprint. A Jet may select one physical
-  body across multiple blocks, never two bodies.
+- Legacy three-level scalar chain: add `child=(x0, y0, x1, y1)` in
+  **L1 window cells** (the patch's fine grid including its 4-cell ghost band) and
+  `child_block`, with `fine_block` and `base_block`. L2 must sit inside L1's
+  ACTIVE cells, away from L1's ghost band and transfer footprint (checked before
+  any GPU allocation). `initialize` and `download` take/return three arrays; each
+  level is NaN on its non-ACTIVE (and child-covered) cells. One coarse step = 2 L1
+  steps = 4 L2 steps. One L1 patch only. Optional stationary circles and Jets
+  live on L2 via `child_objects` and `child_jets`; `fine_objects`/`jets` retain
+  their L1 meaning and must be empty in this mode. All object and Jet geometry
+  uses the **L0 edge frame**, not the child bounds' L1 window frame. L2 has
+  dx=dt=0.25, so prescribed lattice velocity is unchanged. Each whole body and
+  its BFL stencil must be inside L2 ACTIVE cells, outside the transfer footprint.
+  A Jet may select one physical body across multiple blocks, never two bodies.

  ```python
  from CelerisLab.body.geometry.circle import CircleGeometry
@@ -190,26 +188,26 @@ Scope and limits:
  jet = Jet(Tube((6.5, 8.), 0., 3., .3), Parallel(0.), amplitude=.002)
  rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]
  with CudaContext(0) as ctx, FixedPatchStepper(
-          cfg, context=ctx, refinements=[(4, 4, 12, 12), (8, 8, 16, 16)],
-          level_blocks=[(4, 4)] * 3, level_objects=[(), (), (body,)],
-          level_jets=[(), (), (jet,)]) as run:
-      shapes = (run.hierarchy.pairs[0].coarse_shape, run.hierarchy.pairs[0].fine_shape, run.hierarchy.pairs[1].fine_shape)
+          cfg, (4, 4, 12, 12), context=ctx, fine_block=(4, 4), base_block=(4, 4),
+          child=(8, 8, 16, 16), child_block=(4, 4),
+          child_objects=[body], child_jets=[jet]) as run:
+      shapes = (run.patch.coarse_shape, run.patch.fine_shape, run.child_patch.fine_shape)
      run.initialize(*(np.broadcast_to(rest, (9, *s)) for s in shapes))  # 16², 24², 24²
      run.step(4)
-      run.set_jet_amplitude(0, -.002, level=2)  # explicit level selects the driven level
+      run.set_jet_amplitude(0, -.002, level=2)  # default level=1 still addresses L1
      run.step(4)
      coarse_g, l1_g, l2_g = run.download()  # solids/covered/nonleaves are NaN
  ```
- Level lists (the only constructor): `refinements[l]` describes level `l+1`
-  in allocated level-`l` integer cells; use a rectangle list for a union, or a
-  scalar rectangle for a single window (a scalar child requires a scalar
-  parent). `level_blocks`, `level_objects` and `level_jets` each have one entry
-  per level, including L0. Three or more levels require all-blocked storage and
-  bodies/Jets only on the finest level. Every adjacent pair must preserve
-  inherited ACTIVE coverage, valid donors/receivers, surviving pulls and the
-  upstream transfer footprint. Level `l` takes `2**l` steps per base interval.
-  This describes implemented topology and scheduling, not accuracy or
-  convergence qualification.
+- Level lists: `refinements[l]` describes level `l+1` in allocated level-`l`
+  integer cells; use a rectangle list for a union, or a scalar rectangle for a
+  single window (a scalar child requires a scalar parent). `level_blocks`,
+  `level_objects` and `level_jets` each have one entry per level, including L0.
+  These lists are mutually exclusive with the legacy patch keywords. Three or
+  more levels require all-blocked storage and bodies/Jets only on the finest
+  level. Every adjacent pair must preserve inherited ACTIVE coverage, valid
+  donors/receivers, surviving pulls and the upstream transfer footprint.
+  Level `l` takes `2**l` steps per base interval. This describes implemented
+  topology and scheduling, not accuracy or convergence qualification.
 - Blocked body levels can enable `observe_raw_exchange=True` and call
  `read_raw_exchange(body_id, level=...)` after a completed base interval.
  It reduces unique cut-link observations into wall/aperture/total force,
@@ -394,12 +392,6 @@ before `run()`, the force will be reset to zero. For the common usage pattern
 | `sim.load_checkpoint(path)` | Restore from HDF5 (config must match) |
 | `sim.snapshot()` / `sim.restore()` | In-memory field snapshot |

-In-memory snapshots save populations only. Restore keeps the current clock,
-controls, observations, geometry and flags; use it only while geometry is
-unchanged. This is not a restart or an FSI rollback. In particular, do not
-restore a snapshot taken before a translating circle changed position.
-This geometry restriction is a caller precondition, not a runtime check.
-
 #### Low-level access

 | Attribute | Description |
@@ -1,57 +0,0 @@
-# Compatibility and API changes
-
-Changes that can make a previously accepted setup or call behave differently.
-Each entry names the commit, the affected entry points and the observable result.
-
-## Redundant periodic stepper alias removed
-
-`PeriodicPatchStepper` is no longer exported from `lbm.refinement_stepper`.
-Use `FixedPatchStepper` with the same arguments, including explicit
-`level_blocks`. The old name was an alias for that exact class; periodic
-boundaries remain the default. Existing imports of the old name must be updated.
-
-## 87c3a31: cut-link ownership is validated for every body
-
-`validate_cut_link_ownership` (`body/preprocess/flag_overlay.py`) now runs for
-passive bodies as well as Jet/aperture bodies. Every cut link must have an
-active fluid receiver (FLUID set, SOLID clear), and each `(receiver, direction)`
-population may have only one writer.
-
-Rejected with `ValueError`, before flags, populations or device buffers change:
-
-1. Overlapping or touching passive solids whose cut links write the same
-   population ("Boundary requires unique cut-link writers").
-2. A body whose cut-link receiver is a non-fluid cell, e.g. a channel wall row
-   or the inlet/outlet column ("Cut links must have active fluid receivers").
-
-Both were previously accepted silently for passive bodies; the interpolated
-boundary then had undefined results. The rules apply to the cut links of all
-bodies together, so a passive body overlapping a Jet body is rejected as well.
-The check runs in `Simulation.initialize`, runtime body sync (`sync_bodies`),
-checkpoint save and checkpoint load (`common/checkpoint.py`). Load validates
-before restoring anything, so a checkpoint whose saved geometry violates either
-rule no longer restores; rebuild the geometry with separated bodies.
-
-## 87c3a31: `Simulation.read_surface_exchange` accepts Jet-driven bodies
-
-`read_surface_exchange(id)` previously required `SurfaceActuation` on the body.
-It now also accepts bodies that own Jet aperture links, including Jets with zero
-or negative amplitude (the aperture test is geometric). Bodies with neither
-`SurfaceActuation` nor aperture links still raise
-`ValueError("Body has no surface actuation")`. The value is unchanged: the latest
-step's wall/aperture exchange, not total nozzle force.
-
-## 7afb5ad: `Simulation` fails closed after a Jet amplitude device-write failure
-
-`Simulation.set_jet_amplitude` previously only documented that a device error
-leaves the per-link velocity column undefined; the instance stayed usable.
-Now any error after input validation (internal stream creation or the upload)
-marks the Simulation failed. Every later device-touching public method,
-including the `stream` property (guard added in the follow-up repair commit on
-`claude/jet-update-consistency`), raises
-`RuntimeError("Simulation failed (...); close() and recreate it")`. The host
-amplitude keeps its previous value. `close()` still works and stays retryable;
-cached host readers and host staging calls are not blocked. Invalid input
-(`ValueError`/`IndexError`) is unchanged: it raises before any change and the
-instance stays usable. `FixedPatchStepper.set_jet_amplitude` already failed the
-instance (status `failed`) and is unchanged.
@@ -1,86 +0,0 @@
-# Continuous VIV videos
-
-Research-only, two separate settings, each one uninterrupted OFF -> ON -> OFF
-fluid/oscillator trajectory. No production changes, topology switching, moving
-checkpoint feature, retraining, force filtering, or parameter search.
-
-The user selected separate videos because runtime topology changes are unsupported
-with translating circles. This is deliberately different from the old Legacy
-multi-setting video, which rebuilt solvers and transferred full state.
-
-## Frozen physical and control contract
-
- Source baseline `73d3f6214e0d28ced4744665aa3bb05522aa2fa8`; D40, U=.005,
-  nu=.004, MRT/FP32/unshifted double-buffer. Same parabolic regularized inlet,
-  NEQ outlet and bounce-back walls as the retained m*=4 pair.
- Common transverse assembly: m*=4 (all three disks), fn D/U=.2, zeta=0.
-  Structure uses previous native-step sum CME_y+Wen_y. No policy-force averaging
-  is applied to this RHS. Same +/-D travel, speed, finite-state and no-donor stops.
- Each phase: Karman400 complete SI of3200, steady320 SI of4000 native steps
-  =160 D/U. Steady's SI follows the actual old video1000-step interval under
-  diffusive D40 scaling, rather than borrowing PPO's800-step interval. Total480 D/U.
-  No extension, retuning or replacement if steady motion/control is weak.
- Steady: canonical new-reproduce constant surface velocities
-  (0,-5.1,+5.1) U. This is NOT a PPO transfer. No model/normalizer is loaded.
-  Existing 2,048,000-step at-rest warmup precedes the free response.
- Karman: actual pinball Re_D50, historically named `karman_re100`, frozen
-  model `148240c1dcb8b11d8e5a0a9e991f6874c4e799c9744707bf0fb32a8efeb0468d`
-  and norm `534fda818c030a56960e95d0f3ac1e350d887d03db7f80f1d6453195a502b7f0`.
-  Use the verified static release once, at video start (clock4576000).
- Both switches occur on SI boundaries. The oscillator y/v, previous RHS,
-  both DDF buffers, moving geometry and solver clock are never reset. OFF still
-  gathers sensor/CME observations. First PPO action uses the immediately previous
-  complete OFF interval, unlike an independent arm's initial all-zero observation.
-  Deterministic feed-forward PPO has no recurrent state. EMA resets to zero each
-  SI, as in training/reproduction; original video's SplitAdvance also reset the
-  constant-steady actuation every interval. Physical OFF is exactly zero wall speed.
-  There is no extra transition blend. The first1 D/U after either switch is
-  explicitly labeled a switch transient. ON from an already moving state differs
-  from the previous independent pair; +/-D stops are retained without retuning.
-  A visual ON label means enabled control,
-  not a proven suppression/cloaking result.
-
-## Video provenance and presentation
-
-Read-only source: DynamisLab `src/drl_pinball/reproduce/continuous_video.py`, SHA256
-`3bd9c777171c9e8932c78298accbb6f61a8323b0eed5938e0f56e167b3df0743`.
-Approved original MP4 SHA256
-`578d2cf5113429006b6919bbb8ef8ff6ce65ebcd0c056ac478f8ce2515e4cbab`.
-The actual new-reproduce conversation confirms fixed-position plain-language
-labels, white bars, OFF/ON toggle, rotation sectors, and 1/2/5/10/5/2/1 gears.
-
-Only the display idiom/gear schedule are reused. Legacy population decoding,
-physics, topology handoff and policy runner are not imported. Modern macroscopic
-fields feed centered vorticity with all stencil nodes fluid. Fixed color limits
-[-3,+3], 21 RdBu_r bins; per-frame clipping fraction retained. Box downsampling
-is display-only. Both main field and enlarged inset have fixed lab coordinates;
-the inset shows the equilibrium line. Actual moving centers and applied surface
-speeds drive the body overlays. y/D trace has fixed +/-1 limits. No motion gain.
-
-1280x800,30fps; first80 D/U of each phase uses the original display gear ramps,
-last80 D/U uses normal cadence (800 native steps/frame =.1D/U). Every native
-step and every SI is still executed. Streaming ffmpeg avoids stored PNG sequences.
-Keep raw scalar histories, SI observations/actions, per-frame time/motion records,
-selected keyframes, source/input hashes and terminal status. These are new
-continuous runs, not an exact replay of the old independent paired histories.
-
-## Gates and limits
-
-CPU: switch-state/clock continuity, first ON observation, exactly zero OFF action,
-SI timing despite sampling, physical scaling, schedule monotonicity, vorticity
-sign/mask, fixed-coordinate mapping. Real smoke:32 warmup +3x32 response steps
-on D40 (smoke SI32), all switches/encoder; not a physical comparison. Grok reviews
-the exact research diff before full runs. Capture no-donor, finite state, native
-RHS and all stop outcomes. Report per-phase late-half motion statistics and
-raw-force limits; appearance and successful duration are not physics qualification.
-
-Example (outputs must be new, outside checkout; select a safe GPU):
-
-```sh
-CUDA_VISIBLE_DEVICES=0 PYTHONPATH=src python research/continuous_viv/run.py --scene steady --out /tmp/celeris-results-continuous-viv/steady
-CUDA_VISIBLE_DEVICES=0 PYTHONPATH=src python research/continuous_viv/run.py --scene karman --model /tmp/celeris-karman-viv-assets/model.zip --norm /tmp/celeris-karman-viv-assets/norm.json --release-dir /tmp/celeris-results-karman-viv-516975e/pair --out /tmp/celeris-results-continuous-viv/karman
-```
-
-Append `--smoke` and use separate output directories for the bounded gates.
-The Karman smoke does not read/install the physical release. Source and review
-SHA, interpreter/version and GPU resource readings belong in the execution receipt.
@@ -4,7 +4,7 @@
 G-to-G explosion reconstruction. The omitted/default `"constant"` selector retains
 the same kernel, launch arguments and device allocations. Projected mode adds two
 compact tables per adjacent pair; recursion, collision, BFL, restriction, buffer
-ownership and synchronized publication are unchanged. `remap_finest` preserves it.
+ownership and synchronized publication are unchanged. `remap_child` preserves it.

 Runtime eligibility is periodic-root, fully blocked D2Q9/SRT/FP32, body/Jet-free,
 without LES; the fixed-patch backend has no forcing interface. Shifted and unshifted
@@ -25,7 +25,7 @@ under the alternate compile branch.
 - No LES, no external forcing (`d_params` force fields stay zero).
 - Shifted Jets stay SRT-only: `body/jets.py` keeps its existing guard. This extension does not
  provide shifted MRT Jets.
- `PeriodicBlockStepper` (uniform blocked stepper) remained SRT-only; it was removed in 8e1feff and its single-level capability, still SRT-only, is `FixedPatchStepper(refinements=[])`.
+- `PeriodicBlockStepper` (uniform blocked stepper) remains SRT-only.

 ## Evidence status
 CPU: `tests/unit/test_refinement_mrt.py` (host guards, source contract). GPU:
@@ -1,6 +1,6 @@
 # Blocked AMR root channel increment

-Opt in with `FixedPatchStepper(..., coarse_boundary="channel", refinements=[bounds], level_blocks=[(by,bx), (fy,fx)])`. Every level must be blocked. The supported boundary is the existing uniform D2Q9/SRT/FP32 double-buffer channel: local Zou-He west inlet, pressure-NEQ east outlet, stationary halfway bounce-back y walls. Uniform and parabolic inlet profiles and shifted/unshifted storage are supported; the existing configuration guards still reject MRT/LES and incompatible storage. This does not change the external DFG MRT reference.
+Opt in with `FixedPatchStepper(..., coarse_boundary="channel", base_block=(by,bx), fine_block=(fy,fx))`, or the existing level-list form. Every level must be blocked. The supported boundary is the existing uniform D2Q9/SRT/FP32 double-buffer channel: local Zou-He west inlet, pressure-NEQ east outlet, stationary halfway bounce-back y walls. Uniform and parabolic inlet profiles and shifted/unshifted storage are supported; the existing configuration guards still reject MRT/LES and incompatible storage. This does not change the external DFG MRT reference.

 `step/block_channel.cu` is a small root-only kernel. Fine kernels, transfer kernels and recursive hop scheduling are unchanged. Global coordinates and the global profile height/velocity are separate from block-local storage strides. Corner ownership and collision phases match `OneStep`:

@@ -1,116 +0,0 @@
-# src coherence stage (from main 914906e)
-
-Owner direction 2026-10-28: unified style over historical compatibility, inside `src`.
-No numerical change is intended. Stages after 5f69eba: 65339ab (one boundary/Jet record,
-host preparation helpers, pair accessors), c5a3cdb (`block_collide` families), 442979b
-(exchange metadata on the boundary record). All three received parent/candidate
-generated-config and host/GPU equality checks. Only the collision slice ran a new PTX
-matrix (a4fc46d, whose src is identical to c5a3cdb); 65339ab and 442979b reused prior
-PTX evidence after unchanged CUDA/compiler and generated-input checks. In the collision
-matrix, only the two channel-root SRT modules changed PTX (omega load/clamp moved);
-their parent/candidate outputs matched exactly in the exercised cases.
-
-## Conventions (defined once, in `lbm.hierarchy.Hierarchy`)
-
- Level `l = 0 .. depth-1` (0 = root). Pair `hierarchy.pairs[l-1]` builds level `l`.
- Array shapes are `(ny, nx)`; rectangles, origins and centers are `(x, y)`.
- Coarse/fine name the two members (parent/child) of ANY pair, not absolute L0/L1:
-  `fine_shape`, `fine_origin`, `prepare_fine_boundary`, `blocked_fine_tables`,
-  `blocked_coarse_tables`.
- Refined levels (l >= 1) of FixedPatchStepper place bodies/Jets in the root EDGE frame
-  (root cell `i` = `[i, i+1)`). Uniform `Simulation` objects AND the static circles of a
-  single-level (depth 1) FixedPatchStepper use the integer-NODE frame. Nothing converts
-  between them. This concerns input placement only: within the EDGE frame, refined
-  levels still project root-edge coordinates to fine-local cell indices with the
-  half-cell shift (`prepare_fine_boundary`: `(v - o)/dx - .5`; hits back via `fine_hits_to_edge_frame`
-  `origin + dx*(hit + .5)`), using `edge_frame`/`fine_origin` below.
- `Hierarchy.edge_frame(l)` -> `((ox, oy), h)`: cell `(i, j)` of level `l`'s allocated
-  array (ghost band and holes included) covers `[o + h*i, o + h*(i+1))`. A scalar
-  FixedPatch2D window carries the half-coarse-cell ghost shift `bounds - HALO/2` in
-  `fine_origin`; a set's level-wide grid has origin 0. Level 1 boundaries are built from
-  the root config (the wall-aware fields live there); deeper ones from the parent frame.
- `FixedPatch2D.fine_level_offset` (was `fine_level_origin`) is an array INDEX offset
-  `(y, x)`, not an `(x, y)` origin.
-
-## FixedPatchStepper migration map
-
-Historical: left column = names at or after 914906e that no longer exist; right column =
-the current name.
-
-| removed / changed | replacement |
-|---|---|
-| `patch`, `child_patch` | `hierarchy.pairs[0]`, `hierarchy.pairs[1]` |
-| `base_layout`, `fine_layout`, `child_layout` (stepper properties) | `layouts[0]`, `layouts[1]`, `layouts[2]` (`FixedPatchSet2D.fine_layout(block)` is unchanged) |
-| `fine_boundary`, `child_boundary` | `boundaries[1]`, `boundaries[2]` (host geometry; `None` = no bodies/Jets) |
-| `_jets` | `jets[1]` |
-| `_boundaries[l]` (dict from L1, level keys), `_level_boundaries` (b4eacf7), `_device_boundaries` (65339ab) | `_boundaries[l]`: the one combined per-level `_BlockedBoundary` record (list from L0, `None` at L0 unless single-level static circles): host geometry `.host`, `.tables`, `.jets`, `.jet_cache`, exchange `.spacing`/`.centers`, device handles |
-| `_fine_tables`, `_actuated`, `_jet_cache` | `_boundaries[1].tables` / `.actuated` / `.jet_cache` |
-| `_level_jets` (private) | `_boundaries[l].jets` (public `jets[l]` is derived) |
-| `_exchange_spacing[l]`, `_exchange_centers[l]` (private) | `_boundaries[l].spacing` (h_l, root units) / `.centers` (root edge frame); only levels with a boundary report exchange |
-| `_level_blocks` (private) | `_layouts[l].block` |
-| `_remap_cfg` (private) | `_root_cfg` |
-| `refinement_tables.blocked_base_tables` (also via `refinement_stepper`) | `refinement_tables.blocked_coarse_tables` (import from `refinement_tables`; the stepper no longer re-exports) |
-| `_fine_leaf`, `_child_leaf` | `leaf[1]`, `leaf[2]` (copies) |
-| `_middle_kind` | `hierarchy.kinds[1]` |
-| `_boundary_hosts` (private) | public `boundaries[l]` = `_boundaries[l].host` (host geometry only; the private record is the combined one) |
-| `remap_child(rects, child_objects=...)` | `remap_finest(rects, objects=...)` |
-| `set_jet_amplitude(i, a)` (implicit level 1) | `set_jet_amplitude(i, a, level=l)` (required) |
-| `read_raw_exchange(b)` / `read_exchange_window(b)` (implicit level 1) | `read_raw_exchange(b, level=l)` / `read_exchange_window(b, level=l)` (required) |
-| `_level_name(l)` "base/fine/child" messages | `"level l"` |
-| `refinement.MIN_PATCH_GAP` | deleted (no gap policy exists) |
-| `params.cuh HaloPlan`, `collide_trt_no_force` | deleted (zero references) |
-
-Kept: `step_count`, constructor keywords (`refinements`, `level_blocks`, `level_objects`,
-`level_jets`, `coarse_boundary`, `explosion`), `Simulation.set_jet_amplitude(i, a)` (one level),
-`RemapTopology.from_config(..., child_objects=, child_jets=)` (internal remap helper; "child" =
-the replaced level relative to its parent).
-
-## Responsibilities
-
- Construction: `_check_levels` (inputs); host preparation, numpy only, before any device
-  work: `_level_layouts`, `_kernel_configs` (per-level kernel configs), `_host_boundaries`,
-  `_prepare_blocked_boundary`, `_fluid_leaves`; `Hierarchy.edge_frame` (geometry frames);
-  then `_planned_bytes()` (memory preflight) and `_build_level` / `_build_pair` /
-  `_upload_boundary` (device). A construction failure closes the partial instance.
-  Observation reads share `_observed_boundary` + `_summarize`.
- Pair accessors: `rectangles` (a scalar FixedPatch2D gives `(bounds,)`) and
-  `fine_level_offset` (`(0, 0)` for a set) on both pair types; the types and their
-  storage frames stay distinct.
- Per-level state, by lifecycle:
-  - Fixed plan structure (built once in `__init__`, read by `_planned_bytes()` before any
-    allocation, readable after `close()` through the public views): `_layouts`,
-    `_level_cfgs`, `_leaf`, `_state`, and in each `_boundaries[l]` record the host geometry
-    `.host`, link tables, `.jet_cache`, `.spacing`, `.centers`.
-  - Mutable boundary data in the same record: `.jets` and `.tables["surface_velocity"]`,
-    changed only by `set_jet_amplitude` (host prepare -> device write -> commit; an uncertain
-    write fails the instance); device handles (`.flags`, `.device`, `.kernel`, ledgers) are
-    set by `_upload_boundary` and cleared by `close()`.
-  - Runtime: `_levels` (`_Level`) holds compiled modules, kernels, the two population
-    buffers (swapped per step) and transfer/kind handles. It is created only after the
-    memory preflight and cleared on `close()`; `.layout`/`.boundary` reference the plan for
-    `_hop`. Folding the plan into `_Level` would mix both lifecycles in one record.
- Blocked kernels: `operators/block_collision.cuh block_collide` is the one collision extension
-  point of `BlockStep` and `BlockChannelStep`. It computes rho/u once and reads no runtime
-  force (`d_params.fx/fy`). Two compile-time families: uniform-equivalent (MRT on any level,
-  SRT on the channel root `BLOCK_ROOT_BC == 2`): clamped omega, `collide_mrt_no_force` or
-  `collide_srt` with its zero Guo term; and level SRT (`BLOCK_ROOT_BC` 0/1): unclamped omega,
-  `collide_srt_no_force`, with the shifted direct-momentum feq under `USE_DDF_SHIFTING`.
-  The uniform path keeps `collide_dispatch` (runtime force, LES, TRT).
- `explosion="projected_linear"` stays an optional capability; `"constant"` stays default.
-
-## Not done / open
-
- Two per-level config derivations stay distinct on purpose: `Hierarchy.configs`
-  (`_middle_config`, wall fields reset on every refined level, geometry validation) vs.
-  `FixedPatchStepper._kernel_configs` (reset only on level 1 of a slot_reservoir root;
-  generates each level's config.h). Folding them needs a config.h/PTX diff gate.
- No single-`Simulation` facade over FixedPatchStepper: the two own different state models
-  (uniform node frame, body sync, forcing, checkpoint vs. fixed blocked hierarchy, edge
-  frame, remap-as-new-instance). A facade would only forward calls; no concrete need found.
- Deferred, each needing its own evidence first: sharing the channel-root cell/donor selector
-  with OneStep (the closure functions are already shared; a shared selector changes uniform
-  signatures and needs a uniform PTX gate); merging FixedPatch2D into FixedPatchSet2D
-  (different origin, ghost band, layout size and addressing; needs a geometry/parity table and
-  would need tiles that are not grid-aligned); one `clamp_omega` helper for uniform and
-  blocked paths (it lives in the hash-pinned LES header `turbulence_smag.cuh`).
- Tests, examples and validation callers are migrated separately (pinned runners stay frozen).
@@ -1,393 +0,0 @@
-# Evidence index (draft, R0)
-
-Active-tree evidence at candidate 0f8fdbc30ea640c764b38ee598d8f4d135c81c85, classified for the release cleanup
-(thread C0C78UFKGRM 1793021833.593279). Draft for review: nothing is removed by this file.
-Recovery of any listed file: `git show 0f8fdbc3:<path>` (blob id given; an immutable tag is requested as anchor).
-
-Classes: K = conclusion kept in the active tree; K-code = tested research code kept; D-snapshot = pre-Gitea
-patch/diff transport (code landed in git from ed1a6ee on; not yet verified hunk by hunk); P-pin = generated hash inventories, git-status dumps and manifests;
-R-raw = run outputs, logs, signals, frames, one-shot run scripts and handoff notes. D, P, R leave the active tree in R1.
-No file under src/ or a test reads any of these paths (git grep at 0f8fdbc3); runners under tests/validation
-that read research/j* are handled in R2.
-
-| Class | Files | Bytes |
-|---|---:|---:|
-| K | 31 | 196,506 |
-| K-code | 3 | 24,324 |
-| D-snapshot | 18 | 338,948 |
-| P-pin | 50 | 979,177 |
-| R-raw | 142 | 3,790,554 |
-
-## (root)
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| BASELINE_JET_AMR.txt | R-raw | 5,244 | 62aa2a66dc05 |
-
-## output
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| round3_compatibility_summary.md | R-raw | 4,366 | f243318f5591 |
-
-## research/fine_surface_20261014
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 54,507 | 71a4543ead37 |
-| cpu_device_guard_cmd.txt | R-raw | 241 | 06e0f35d92b3 |
-| cpu_device_guard_exit.txt | R-raw | 2 | 573541ac9702 |
-| cpu_device_guard_stdout.txt | R-raw | 98 | 424d584a031c |
-| cpu_existing_runs.json | R-raw | 650 | 3179536407b7 |
-| cpu_final_run.json | R-raw | 386 | 523fadb3fec9 |
-| cpu_final_stdout.txt | R-raw | 99 | 9cfe73da3858 |
-| cpu_lifecycle_run.json | R-raw | 387 | 5b403b9e2f30 |
-| cpu_lifecycle_stdout.txt | R-raw | 112 | 3c5c49b285fa |
-| cpu_maps_stdout.txt | R-raw | 95 | 71dd87f9faf9 |
-| cpu_preallocation_run.json | R-raw | 337 | fa6e96d98cdd |
-| cpu_preallocation_stdout.txt | R-raw | 98 | 5d643576f251 |
-| cpu_shared_kernel_stdout.txt | R-raw | 98 | 8a0c046bb9b1 |
-| cpu_surface_command.txt | R-raw | 113 | 2a5ff31e8d06 |
-| cpu_surface_exit.txt | R-raw | 2 | 573541ac9702 |
-| cpu_surface_projection_command.txt | R-raw | 171 | 70b7f5c62c1a |
-| cpu_surface_projection_exit.txt | R-raw | 2 | 573541ac9702 |
-| cpu_surface_projection_stdout.txt | R-raw | 113 | efd37a149cc1 |
-| cpu_surface_stdout.txt | R-raw | 99 | 9cfe73da3858 |
-| gpu_preparation_run1.py | R-raw | 14,043 | ee586d035b7a |
-| gpu_run.json | R-raw | 2,943 | 15b8ba70d528 |
-| gpu_stdout.txt | R-raw | 5,424 | c5216e0267f3 |
-| gpu_test_run1.py | R-raw | 15,479 | f30376abc97f |
-| incremental.diff | D-snapshot | 53,853 | 318d92e7d177 |
-| manifest.json | P-pin | 8,411 | 8281338416af |
-| report.txt | K | 8,373 | 6b9e5123e414 |
-
-## research/fine_surface_joint_20261014
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline_00.json | P-pin | 21,302 | 4ae101ebd02b |
-| baseline_01.json | P-pin | 26,191 | 548cf7b3b494 |
-| baseline_02.json | P-pin | 22,440 | e0421e7a4052 |
-| baseline_03.json | P-pin | 8,584 | da99b45f32a4 |
-| blow_boundary.csv | R-raw | 12,536 | e13363b69457 |
-| blow_collisions.csv | R-raw | 19,145 | 5d5b395486bb |
-| blow_ledger.csv | R-raw | 15,977 | b43bbfd0b8d2 |
-| blow_propagation.csv | R-raw | 9,714 | f06d80d296ca |
-| blow_signals.npz | R-raw | 221,114 | 528adf75baa2 |
-| blow_summary.json | R-raw | 4,113 | 32285ac15be3 |
-| command.txt | R-raw | 232 | 510ecb2925dd |
-| criteria.txt | K | 7,480 | dd36e76a3be1 |
-| frozen.json | R-raw | 11,972 | b5a3324e8686 |
-| gpu_run.json | R-raw | 1,955 | 67ac4785f7e4 |
-| incremental.diff | D-snapshot | 625 | e03c132d22df |
-| integrity.json | P-pin | 826 | a8b6e4be88d2 |
-| manifest.json | P-pin | 4,388 | d2af50260c39 |
-| regions.json | R-raw | 27,525 | 7bba26904221 |
-| report.txt | K | 8,207 | d7571e068ad3 |
-| result.json | R-raw | 11,442 | 9580c2686e70 |
-| review.txt | K | 2,117 | bbe1d8a83d47 |
-| runner.py | R-raw | 5,847 | 812973acc000 |
-| stdout.txt | R-raw | 19,940 | c9218e2e48fc |
-| suction_boundary.csv | R-raw | 12,505 | b870be05e6c0 |
-| suction_collisions.csv | R-raw | 19,173 | 2de48c0a84ab |
-| suction_ledger.csv | R-raw | 16,208 | 92cf1f44911e |
-| suction_propagation.csv | R-raw | 9,720 | f017bcc3ca6f |
-| suction_signals.npz | R-raw | 220,058 | 66d06cf2d909 |
-| suction_summary.json | R-raw | 4,126 | d70a1d371950 |
-| validate.py | R-raw | 19,576 | 37441febd168 |
-| zero_boundary.csv | R-raw | 11,491 | 65c92e48c974 |
-| zero_collisions.csv | R-raw | 18,915 | 027cb8ff6b23 |
-| zero_ledger.csv | R-raw | 16,051 | 34a99bb89dd7 |
-| zero_signals.npz | R-raw | 127,958 | a966f093a9cd |
-| zero_summary.json | R-raw | 1,508 | 6e033f991438 |
-
-## research/fixed_patch_jet_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 69,721 | 91ad9c4d1e88 |
-| before.json | R-raw | 690 | 06e1b6278a29 |
-| fixed_patch_jet.py | R-raw | 9,646 | 6fbdcd9a076b |
-| incremental.patch | D-snapshot | 9,891 | b43129d82c69 |
-| manifest.json | P-pin | 1,967 | 08daa0248f60 |
-| notes.txt | K | 2,214 | 50070fe54efb |
-| results.json | R-raw | 1,100 | d959a6a1cc2c |
-| stdout.txt | R-raw | 1,272 | eccdc0f6b16a |
-
-## research/fixed_patch_jet_closure_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 72,692 | 8a157af82ecf |
-| cpu_results.json | R-raw | 628 | 8e4a1c090c93 |
-| cpu_stdout.txt | R-raw | 590 | d800b783fe47 |
-| incremental.patch | D-snapshot | 3,490 | a9a486c68afd |
-| layout_uncropped.png | R-raw | 51,785 | 0cf1cfa5e99d |
-| manifest.json | P-pin | 1,849 | 31cf0c739241 |
-| notes.txt | K | 3,023 | 0f7e7bdfd0e6 |
-
-## research/fixed_patch_jet_records_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 71,228 | a8e967f76e08 |
-| before.json | R-raw | 690 | ebd6f4251fc2 |
-| fixed_patch_jet.py | R-raw | 10,650 | f6b299885da0 |
-| incremental.patch | D-snapshot | 5,539 | c7f4d0c02ccc |
-| manifest.json | P-pin | 2,057 | 1d616c2541df |
-| notes.txt | K | 2,449 | b58cec14d359 |
-| results.json | R-raw | 1,136 | 788af64a6ebd |
-| stdout.txt | R-raw | 20,750 | a765b06deefa |
-
-## research/j1-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 7,667 | 8f469daef054 |
-| baseline-status.txt | P-pin | 2,601 | 64ca05ab952e |
-| baseline.json | P-pin | 23,052 | ab5852bcb0ef |
-| incremental.diff | D-snapshot | 29,912 | dd9c4e688888 |
-| results.json | R-raw | 68,294 | 56547aa8a678 |
-
-## research/j2-slot-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 12,930 | 69fa4d3bccd3 |
-| baseline-status.txt | P-pin | 2,825 | e711afb0016c |
-| baseline.json | P-pin | 24,660 | 286e023da94f |
-| incremental.diff | D-snapshot | 25,231 | 649f3b5d168d |
-| results.json | R-raw | 477,249 | b4272e25179d |
-
-## research/j3-coverage-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 11,409 | 5887cf73dce2 |
-| baseline-status.txt | P-pin | 3,055 | 78e88356caa3 |
-| baseline.json | P-pin | 30,407 | 095972547a7f |
-| incremental.diff | D-snapshot | 20,114 | f0d502dc5c5b |
-| negative-budget-20744.h5 | R-raw | 88,017 | 693b133be84d |
-| negative-end-20760.h5 | R-raw | 88,174 | 429270d263d4 |
-| restart-21280.h5 | R-raw | 88,062 | 74900affae38 |
-| restart-reference-21296.h5 | R-raw | 88,154 | 7510ee97885b |
-| results.json | R-raw | 296,314 | 7806b10e65cb |
-| verification.json | K | 1,468 | 78a07c47aea4 |
-
-## research/j3-lag-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 11,732 | 34fe5dbb2cae |
-| baseline-status.txt | P-pin | 2,968 | 6ae6094ea9d7 |
-| baseline.json | P-pin | 26,505 | 5c289d14ff30 |
-| end-21280.h5 | R-raw | 92,366 | f30b209179ab |
-| incremental.diff | D-snapshot | 15,790 | 5c6c485e1f75 |
-| results.json | R-raw | 21,718 | 2bf58939129c |
-| start-20760.h5 | R-raw | 92,247 | ae0abd05190c |
-
-## research/j3-offline-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 6,271 | a76e1b486bd2 |
-| lags.csv | R-raw | 1,104 | dd3136dd2dc2 |
-| localization.png | R-raw | 136,013 | 74b56f3e814c |
-| regions.csv | R-raw | 2,126 | 5d361e6872af |
-| results.json | R-raw | 8,852 | bf77b0f534d4 |
-
-## research/j3-reservoir-2026-10-12
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| REVIEW.md | K | 13,563 | a74b67a64e0d |
-| baseline-status.txt | P-pin | 2,896 | a318e077dfae |
-| baseline.json | P-pin | 25,571 | 060502ea7dd8 |
-| incremental.diff | D-snapshot | 22,898 | 8e2c79a86c98 |
-| results.json | R-raw | 182,747 | 7fd5e51a1785 |
-
-## research/refinement_example_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 8,286 | 591478100da8 |
-| before.json | R-raw | 818 | 7ab0962775b1 |
-| incremental.patch | D-snapshot | 8,682 | 7ad8719d0167 |
-| manifest.json | P-pin | 1,798 | bf1eee8a7cf8 |
-| notes.txt | K | 1,185 | 7ff019ad023d |
-| results.json | R-raw | 1,118 | 94697b0988b9 |
-| stdout.txt | R-raw | 325 | 501446f557f4 |
-
-## research/refinement_followup_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 4,887 | af65e889f20e |
-| baseline.json | P-pin | 5,343 | 7c60ad8ad692 |
-| cleanup.json | R-raw | 1,253 | 15cf342fba2e |
-| cpu_results.json | R-raw | 1,056 | 1166dffd2a09 |
-| cpu_results_attempt1.json | R-raw | 642 | d139d5508105 |
-| cpu_stdout.txt | R-raw | 499 | d1b33ea20563 |
-| cpu_stdout_attempt1.txt | R-raw | 879 | 6a9fe7fce39a |
-| gpu_before.json | R-raw | 589 | 46762a0ab207 |
-| gpu_before_no_launch.json | R-raw | 589 | 074982d1b2d4 |
-| gpu_rectangle_before.json | R-raw | 589 | 831e3793339f |
-| gpu_rectangle_before_no_launch_1791886104981638567.json | R-raw | 589 | c33885d50bfd |
-| gpu_rectangle_results.json | R-raw | 1,003 | 9c6da219ac6c |
-| gpu_rectangle_stdout.txt | R-raw | 332 | 9185bf303954 |
-| gpu_results.json | R-raw | 1,189 | 53e4f1c44de1 |
-| gpu_seed1_before.json | R-raw | 589 | c77ea3485f84 |
-| gpu_seed1_results.json | R-raw | 996 | b718e8af84e4 |
-| gpu_seed1_stdout.txt | R-raw | 306 | 4d7de0897137 |
-| gpu_stdout.txt | R-raw | 68 | b0956fe3cdb0 |
-| incremental.patch | D-snapshot | 16,836 | 9df25d8c177a |
-| manifest.json | P-pin | 4,410 | 177704d6f1ae |
-| run_gpu.py | R-raw | 5,237 | b5af3f0d4f79 |
-
-## research/refinement_prepare_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 8,939 | 8e210c28c7c5 |
-| baseline.json | P-pin | 46,348 | d5f257216b8d |
-| incremental.patch | D-snapshot | 15,751 | 0ddb32550584 |
-| manifest.json | P-pin | 2,113 | 9fd94ccf2c3e |
-| validation.json | R-raw | 3,567 | f057e7cbcd35 |
-| validation.txt | R-raw | 873 | 594daa45c58c |
-
-## research/refinement_slot_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 67,717 | d498081e7c50 |
-| before.json | R-raw | 690 | 430e76b3aa8a |
-| cpu_results.json | R-raw | 1,421 | 4f6bc4d9428f |
-| incremental.patch | D-snapshot | 18,676 | 67a3e8cc9e68 |
-| manifest.json | P-pin | 2,270 | 6515458290f4 |
-| notes.txt | K | 2,612 | 08a713ba4b37 |
-| results.json | R-raw | 1,160 | 03e683027ba8 |
-| stdout.txt | R-raw | 643 | d57b91769826 |
-
-## research/refinement_slot_followup_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 68,536 | 89a26ce79438 |
-| before.json | R-raw | 690 | e707df192ff2 |
-| incremental.patch | D-snapshot | 495 | c6f6fa11237d |
-| manifest.json | P-pin | 1,920 | 4840243a33aa |
-| notes.txt | K | 1,549 | 4b77583ca116 |
-| planar_velocity.cuh | R-raw | 1,911 | 87db7466c843 |
-| planar_velocity.sha256 | P-pin | 251 | 6694c4a1c1f0 |
-| results.json | R-raw | 1,050 | 6ef6eda854c6 |
-| stdout.txt | R-raw | 1,160 | 461860351c0c |
-
-## research/refinement_step_20261013
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 10,671 | 88d6f24743f5 |
-| baseline.json | P-pin | 40,620 | 20f61559dd38 |
-| cpu_validation.json | R-raw | 1,231 | 7999fd30018c |
-| gpu_failure_validation.json | R-raw | 868 | 5f6db65ee4f9 |
-| gpu_failure_validation.txt | R-raw | 248 | d9a570a1e9e9 |
-| gpu_validation.json | R-raw | 672 | 2028f59e1055 |
-| gpu_validation.txt | R-raw | 632 | 9699918ee127 |
-| incremental.patch | D-snapshot | 26,516 | d95f9347633d |
-| manifest.json | P-pin | 2,075 | 32a7f1a7309e |
-
-## research/repair-2026-10-10
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| TRON_HANDOFF.md | R-raw | 25,208 | a339786c7944 |
-| baseline-hashes.json | P-pin | 16,020 | 9b4e24cb1d10 |
-| baseline-status.txt | P-pin | 429 | 515be249b638 |
-| checkpoint-domain-2026-10-12.diff | D-snapshot | 14,443 | 035ed630dda1 |
-| classic-results.json | R-raw | 244,729 | 7297aa0d5bca |
-| classic-signals.npz | R-raw | 630,332 | 8cf6d1218aa0 |
-| final-gpu.log | R-raw | 191 | a0eec1a8ea31 |
-| final-unit.log | R-raw | 188 | 94efba2f1d42 |
-| provenance.json | P-pin | 1,020 | 25e22b4f0696 |
-| repair-architecture.md | K | 9,498 | 12051c3e8571 |
-| repair-numerical.md | K | 10,769 | 0c5757fe5f36 |
-| repair-state.md | K | 8,481 | 3c7f2d5b687a |
-| simplification-checks.log | R-raw | 1,045 | fa9d464be740 |
-
-## research/shear_refinement
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.md | K-code | 4,142 | 67bdd8ed622b |
-| boundary_shear_tagging.py | K-code | 13,859 | b5415a1c4ea1 |
-| example.py | K-code | 6,323 | 66295d3f0273 |
-
-## research/surface_actuation_20261014
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| baseline.json | P-pin | 54,139 | 0ad06888dbeb |
-| cpu_checkpoint_run.json | R-raw | 400 | 39681b60ff15 |
-| cpu_checkpoint_stdout.txt | R-raw | 114 | 929e4b8d4f46 |
-| cpu_initial.txt | R-raw | 620 | 29213c58a679 |
-| cpu_surface_command.txt | R-raw | 118 | 6d8c615a6e03 |
-| cpu_surface_exit.txt | R-raw | 2 | 573541ac9702 |
-| cpu_surface_stdout.txt | R-raw | 99 | ee9237fc26e5 |
-| gpu_run.json | R-raw | 1,698 | dc8f87eafaa9 |
-| gpu_stdout.txt | R-raw | 159 | b262891e52c3 |
-| incremental.diff | D-snapshot | 50,206 | 43090a1a8b11 |
-| manifest.json | P-pin | 7,527 | 35daa01271cb |
-| report.txt | K | 5,078 | 1162a6479f9f |
-
-## research/wall_seam_pulse_20261014
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| analyze.py | R-raw | 10,343 | ed7cf6999a49 |
-| interpretation.txt | K | 3,514 | 90935db2aa99 |
-| results.json | R-raw | 15,137 | 678a0759871a |
-| run.json | R-raw | 1,170 | 53e303fd0d5d |
-| sources.csv | R-raw | 2,313 | 40d3736b8ef1 |
-| stdout.txt | R-raw | 1,179 | 756d8c38e213 |
-
-## tests/validation/multigrid/cpuref_0_3_evidence
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 4,133 | 62897bfd9812 |
-| README_grok.md | K | 1,751 | 2d36e05661a8 |
-| baseline.json | P-pin | 39,291 | 188491096547 |
-| manifest.json | P-pin | 3,495 | 10c19f5fe5ca |
-| results_horsea.json | R-raw | 2,281 | 3b163384e376 |
-| stdout_grok.txt | R-raw | 7,143 | 5a0c270ea4ae |
-| stdout_horsea.txt | R-raw | 9,013 | adff8bb8d295 |
-
-## tests/validation/multigrid/local_stress_v1_evidence
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 8,239 | 3513fd294223 |
-| TABLE_local_stress_observable_v1.md | K | 2,967 | 6115dcde0f46 |
-| baseline.json | P-pin | 43,991 | ab631ea4f2ad |
-| comparison.json | R-raw | 13,248 | d7d1b36eb247 |
-| manifest.json | P-pin | 4,132 | c6c44d8125cd |
-| results_horsea.json | R-raw | 2,671 | 79bdf001f948 |
-| run_once.py | R-raw | 4,313 | fa9c5239e993 |
-| source_manifest.json | P-pin | 622 | 0516f1860407 |
-| stdout_horsea.txt | R-raw | 17,091 | a20c554693df |
-| stdout_local_stress_observable_v1.txt | R-raw | 12,238 | 692ffe1a05da |
-
-## tests/validation/multigrid/shear_v0_2_evidence
-
-| File | Class | Bytes | Blob |
-|---|---|---:|---|
-| README.txt | K | 7,220 | 772f74ad40ff |
-| baseline.json | P-pin | 41,751 | 70d9c9fa71c0 |
-| comparison.json | R-raw | 7,679 | 0af8736f9a01 |
-| joint_report.md | K | 6,110 | eed871221298 |
-| manifest.json | P-pin | 3,796 | b22d03a1ba9e |
-| results_horsea.json | R-raw | 1,957 | b2cd48a07a08 |
-| run_once.py | R-raw | 3,245 | 0b8d5e21f326 |
-| source_manifest.json | P-pin | 574 | 4d1c742690c7 |
-| stdout_grok.txt | R-raw | 7,950 | 0e80b1aba7f6 |
-| stdout_horsea.txt | R-raw | 11,421 | 3c867cdac197 |
@@ -1,8 +1,8 @@
 # Fixed three-level rectangle unions

-This page describes three-level `FixedPatchStepper` setups built from the
-`refinements` level list, with rectangle unions on either adjacent pair. The
-same constructor supports arbitrary depth; three or more levels require
+This page describes the legacy three-level entry point of `FixedPatchStepper`,
+with rectangle unions on either adjacent pair. The `refinements` level-list
+entry point also supports arbitrary depth; three or more levels require
 all-blocked storage and bodies/Jets only on the finest level. This is not
 general AMR: there is no per-region timestep, moving geometry, automatic
 dynamic refinement or L1 body support in the three-level form.
@@ -12,15 +12,15 @@ No CUDA kernel changes are involved.

 ## Explicit coordinate frames

-For a single scalar parent patch, pass a scalar rectangle as `refinements[1]`:
-`(x0,y0,x1,y1)` in half-open integer indices of the allocated L1 window,
-including its ghost band.
+Keep the existing scalar `child=(x0,y0,x1,y1)` for a single scalar parent patch.
+Its coordinates retain their original meaning: half-open integer indices in the
+allocated L1 window, including its ghost band.

-A rectangle list as `refinements[1]` accepts a scalar or a set parent and
-interprets every rectangle in the actual allocated L1 array, including ghost
-bands and holes. It never infers region-local coordinates. The physical root
-cell edge corresponding to an L1 index `(x,y)` is
-`parent.fine_origin + (x,y)/2`:
+The new keyword `child_rectangles_in_parent=[...]` is mutually exclusive with
+`child`. It accepts a scalar or a set parent and interprets every rectangle in
+the actual allocated L1 array, including ghost bands and holes. It never infers
+region-local coordinates. The physical root cell edge corresponding to an L1
+index `(x,y)` is `parent.fine_origin + (x,y)/2`:

 - A scalar L1 parent has a shifted window origin.
 - A set L1 parent has origin `(0,0)` and public shape `(2*ny,2*nx)`.
@@ -47,9 +47,9 @@ tile edges.

 ```python
 run = FixedPatchStepper(
-    cfg, context=ctx,
-    refinements=[[(4, 4, 20, 28), (24, 4, 44, 28)], [(16, 16, 32, 40), (56, 16, 80, 40)]],
-    level_blocks=[(4, 4)] * 3,
+    cfg, [(4, 4, 20, 28), (24, 4, 44, 28)], context=ctx,
+    base_block=(4, 4), fine_block=(4, 4), child_block=(4, 4),
+    child_rectangles_in_parent=[(16, 16, 32, 40), (56, 16, 80, 40)],
 )
 ```

@@ -57,11 +57,11 @@ This example uses a 48x32 root. `initialize` and `download` use three Q-major
 dense arrays. Public arrays and masks still scale with the full allocated
 extent; sparse device buffers do not remove that host-memory limit.

-Stationary whole-circle L2 bodies and Jets (`level_objects[2]`, `level_jets[2]`) use root edge
+Stationary whole-circle `child_objects` and `child_jets` use root edge
 coordinates and a single L2 boundary object. Body IDs are physical object-list
 positions, not region IDs or caller `obj_id`. Complete boundary stencils must
 avoid the transfer footprint. Change a child Jet with
-`set_jet_amplitude(index, value, level=2)` (`level` is required); L1 bodies/Jets remain unsupported.
+`set_jet_amplitude(index, value, level=2)`; L1 bodies/Jets remain unsupported.

 ## Verification

@@ -1,120 +0,0 @@
-# Re_D = 50 Kármán inflow: paired pinball VIV / frozen PPO demo
-
-Development experiment, frozen before results, 2026-10-31. No new production
-method, structural damping, force filter, policy training, or main merge.
-[Force-spike research index](research/moving_boundary_force_spikes.md).
-
-## Plant and structure
-
-Base `e9213dd2cc9cfed0e8487a3cf4ebdd94d23dc64d`; fixed-policy contract from
-`580397eaf83c85b233495791ecc51662a374a247`. Reuse `steady_pinball` config,
-coordinate map and exact held-force oscillator. D40, U=.005, nu=.004, MRT,
-2559 x 1022, FP32 unshifted double buffers. Regularized parabolic inlet,
-NEQ extrapolation outlet, bounce-back y walls (.5,1020.5); no BC changes.
-D20 coordinates map x'=2x, y'=.5+2(y-.5).
-Upstream cylinder (400,510.5), radius40, is static. Pinballs radius20 at
-(1200,510.5), (1252,540.5), (1252,480.5) share only transverse translation.
-Lab probes radius10 at (1600,590.5), (1600,510.5), (1600,430.5) stay fixed.
-
-One shared `Translation`, travel ±D, max wall speed .025, existing clearance
-and per-step move guards unchanged. M2: m*=2 based on all three disks,
-M=7539.8223686, fn=.000025, K=.000186037660, C=zeta=0; release y=v=0.
-Each native step uses previous-step sum(CME_y+Wen_y), then exact oscillator
-update with held force. Wall speed is interval displacement y[n+1]-y[n].
-Cover/uncover impulses are logged, never added to the selected RHS. This
-estimator remains provisional; existing spike/convergence limitations remain.
-
-## Same release state, two clocks
-
-A static precursor retains the accepted Kármán sequence: upstream+probes,
-2,048,000-step warmup, 150 x 3,200-step no-pinball target samples, add static
-pinballs/sync, second 2,048,000-step warmup. Save both DDF buffers, flags,
-clock and last instantaneous force. Construct each moving arm fresh at the
-same zero-offset geometry, check flags, copy both buffers and clock, verify
-exact copy hashes. This one-time research initialization is not a moving
-checkpoint or FSI rollback. Initial policy observation and spin are zero.
-
-Frozen model SHA256 `148240c1dcb8b11d8e5a0a9e991f6874c4e799c9744707bf0fb32a8efeb0468d`;
-normalizer `534fda818c030a56960e95d0f3ac1e350d887d03db7f80f1d6453195a502b7f0`.
-Only these explicit supplied assets are accepted. Policy is CPU deterministic.
-Native policy signals: packed CME (same `read_force` path), lab area-mean
-velocity, each averaged over SI3200. Convert to original D20 training units:
-forces x2, area-mean velocity x2 x78, then frozen force-first normalization
-and clipping. Fine-grid probe pixel footprint is not exactly identical;
-using the original78 cells avoids a hidden area-count normalization change.
-The moving plant, motion-induced force, lab-frame wake displacement and D40
-resolution remain out of training distribution. No transfer guarantee.
-
-A=(8a+(0,-4,4))*.005; EMA alpha=.9^(1/4), reset0 each SI; omega=+A_eff/20.
-This preserves historical physical actuator timescale under dt/4.
-The zero arm substitutes a=(0,.5,-.5), so all spins are identically zero.
-Policy interval averaging does **not** average the native structural RHS.
-
-## Bound, output, and interpretation
-
-One serial pair, zero then controlled: 400SI=1,280,000 native steps=160D/U
-=32Tn per arm. No retuning/automatic extension. Stop on nonfinite state,
-no_donor, travel/speed/move rejection, or four-hour whole-pair wall cap.
-A failure stops the remaining run; retain valid rows and completed intervals.
-NaN trailing rows are unexecuted, not zero-valued observations.
-
-Report first/last80D/U windows, mean offset separately from centered RMS,
-half-range, peak, frequency and drift; native versus SI-averaged force,
-CME/Wen/node/crossing terms and action/observation clipping. Last80D/U is
-the principal descriptive window, not an asserted settled window. If zero
-arm half-range <.1D there, classify weak response and do not claim vibration
-suppression. Report continuous ratios regardless. Cloaking uses retained
-canonical last30 lagged sensor DTW against this precursor's no-pinball target,
-with fixed-body D20 results contextual only. These are development criteria,
-not paper uncertainty, grid convergence, or proof of validated FSI.
-
-Save native18-column rows (~184MB/arm), small SI signals, target, config,
-release two buffers (~188MiB), hashes and terminal reports outside checkout.
-No per-step field output. Expected new data <650MB, check actual resources.
-
-```
-CUDA_VISIBLE_DEVICES=0 PYTHONPATH=src python research/karman_viv/run.py \
-  --model /tmp/celeris-karman-viv-assets/model.zip \
-  --norm /tmp/celeris-karman-viv-assets/norm.json --out /tmp/NEW_OUTPUT
-```
-
-First `--smoke`: same D40 geometry, warmup32/target2x8/warmup32,
-4x8 response steps each arm; strictly plumbing only. CPU source checks and
-independent exact-tip review precede GPU. Preserve original DynamisLab files.
-
-## One predeclared m*=4 exploration (2026-10-31)
-
-The m*=2 attempt at `516975ef6482f983ace347cb10de7450d2fbd680` stopped
-at the declared travel guard in both arms: zero 10.469375 D/U, PPO 27.5525 D/U.
-Its principal 80–160 D/U paired window is unavailable. Early attenuation is
-not sustained suppression; control-only DTW is not a paired cloaking result.
-Those results remain unchanged and retained.
-
-The sole next candidate doubles M and K together: m*=4, M=15079.644737231,
-K=0.000372075320164, fn=0.000025, C=zeta=0. This increases inertia and stiffness,
-not damping. Half response under an identical prescribed external force is
-the selection rationale only; coupled flow feedback can invalidate it. This
-is an exploratory development case, not independent validation or a sweep.
-
-Reuse the exact saved static release, config, target, model and normalizer.
-`--release-dir` checks precursor metadata, config equality, both DDF/flags
-hashes and clock against the original transfer receipt. Each fresh arm still
-checks its upload against that seed. No warmup, moving restart or new release
-file is generated. All fluid/geometry/EMA/SI/RHS settings, 400SI per arm,
-zero damping, ±D guard and other stop conditions above remain unchanged.
-The original failure stops the remaining run rule also remains unchanged.
-
-```
-CUDA_VISIBLE_DEVICES=0 PYTHONPATH=src python research/karman_viv/run.py \
-  --model /tmp/celeris-karman-viv-assets/model.zip \
-  --norm /tmp/celeris-karman-viv-assets/norm.json --out /tmp/NEW_M4_OUTPUT \
-  --mass-ratio 4 --release-dir /tmp/celeris-results-karman-viv-516975e/pair
-```
-
-Report matched valid windows only, separately retaining mean offset,
-centered RMS, half-range, interval/native forces, crossing/diagnostic counts
-and paired DTW only where both arms have sufficient data. The larger
-controlled force excursions remain unresolved: retained m*=2 data strongly
-associate them with the post-action-reset ramp, not exclusively current-step
-node switching. No force smoothing, action-contract change, enlarged travel
-band or further parameter adjustment follows an unsuccessful outcome.
@@ -1,26 +0,0 @@
-# Device state lifecycle (uniform Simulation, FixedPatchStepper)
-
-State is grouped by what a change invalidates. This file describes the code as
-it is; it adds no framework. Line references are to candidate 0f8fdbc3.
-
-| Class | Contents | How it changes | Owner rule |
-|---|---|---|---|
-| 1. Module and its globals | Compile-time (visible to the compiler, fixed per module): `config.h` macros incl. `NX`/`NY`, `COLLISION_MODEL`, `BLOCK_ROOT_BC`, `WALL_*`. Runtime per-module globals (not visible to the compiler; written by host code): `__constant__` `d_params`, `d_w`, `d_cx`, `d_cy`, `d_block_channel`, `d_block_wall`; plus bound kernel handles | Globals are written once by the owner right after `load_module`. Uniform grid: `Simulation._recompile` (construction, body-topology sync) loads a new module and re-uploads; `update_runtime_params` rewrites `d_params` (omega, force, n_objects) between runs. Steppers: never rewritten after construction, so they are immutable for the instance's lifetime although they are runtime values. The blocked slot/reservoir root reads its slot from the `d_block_wall` constant (the former dense route used `WALL_*` macros; both were bit-identical in the parity gates). | Every owner loads its own module (`compiler.load_module` = `module_from_file`, no cache). A loaded module is never shared between live owners: globals are per module, so sharing would share mutable `d_params`. |
-| 2. Geometry, layout, tables | flags, curved-link tables, block layouts and halo pairs, transfer (explode/coalesce) tables, block kinds | Immutable for the life of an instance, except translating circles on the uniform grid: their swept-band flags and cut links are rewritten on the device every advancing step (`MovingCircleCells`/`MovingCircleLinks`, docs/moving_bodies.md); the host flag mirror is then stale for those cells. Uniform grid otherwise: rebuilt by body sync. `FixedPatchStepper`: a geometry change is a new instance (`remap_finest`), committed only after a successful transfer. | No in-place table edits. |
-| 3. Controls and dependent boundary columns | Jet amplitude -> per-link `surface_velocity`; body actions (uniform grid) | Between steps, without a table or module rebuild (`set_jet_amplitude`). | Input (index, level, amplitude) is validated before any device write; invalid input changes nothing and the instance stays usable. The host copy commits only after the upload returned. Any error after validation leaves the device column undefined and fails the instance: `FixedPatchStepper` status `failed`, `Simulation._failed`; every later device-touching public method (`Simulation`: `stream`, `set_jet_amplitude`, `initialize`, `sync_bodies`, `run`/`step`, `read_surface_exchange`, `read_body(s)`, `get_macroscopic`, `get_ddf`, `update_runtime_params`, `snapshot`, `restore`, save/load checkpoint) raises; cached host readers and host-side staging (e.g. `get_flags` without translating circles, `add_body`/`remove_body` before a sync) do not touch the device and stay callable; with translating circles `get_flags` reads the device flags back and refuses after a failure. Translating-circle targets follow the same rule: `set_body` validates before mutation, the applied offset commits only after a successful synchronized step, and a failed moving step fails the instance (docs/moving_bodies.md). `close()` still releases resources and stays retryable. |
-| 4. Per-step state | population double buffers and their parity, raw-exchange ledgers, observations | Device-only during `step(n)` / `run(n)`; buffer swaps are host-handle swaps. | Valid on the host only after the single wait at the end of the call. |
-
-Storage routes are separate concerns:
-
- Original uniform grid (`uniform.cu`, `Simulation`): whole-domain `NX`/`NY`.
- Blocked levels (`blocked.cu`; every `FixedPatchStepper` level, including the
-  single level of `refinements=[]`): `NX`/`NY` are one block window including halo.
- Dense refinement levels (`refinement.cu`) were removed: `level_blocks` is
-  required and every refinement level is blocked.
-
-A single-rectangle refinement (`FixedPatch2D`) is stored in its own fine
-window frame (`FixedPatchStepper.__init__`,
-`BlockLayout2D.build(*pair.fine_shape, ...)`). Only a rectangle set
-(`FixedPatchSet2D`) uses the level-wide frame `(2*ny, 2*nx)`, whose
-`fine_layout` requires that full grid to be divisible by the tile
-(`refinement.py:240-252`).
@@ -1,451 +0,0 @@
-# Moving circles on the uniform dense grid
-
-## Status and user guide (current)
-
-Development-stage feature, integrated from the reviewed slices S1–S3a
-(production code identical to `653fd997`). Physical evidence and its limits:
-`docs/validation/moving_bodies_stage1.md`. The force used as a structural RHS
-is a declared stage choice, not an established result.
-
-*What it does.* Translating circles (with optional spin) on the dense
-double-buffer D2Q9 path: per-step cut links from an FP64 geometry record
-(M2 `MovingCircleLinks`), reclassification and refill of covered/uncovered
-cells (M1 `MovingCircleCells`), moving-wall Bouzidi with wall velocity
-`u + omega x r`, and separate per-body diagnostics.
-
-*API.*
- `Simulation.add_body("circle", center=(x, y), radius=r,
-  translation=Translation(offset_box, max_speed))` before `initialize()`;
-  `offset_box = (x_min, x_max, y_min, y_max)` in lattice cells around the
-  base centre (must contain 0), `0 < max_speed ≤ .5`.
- `set_body(id, offset=(dx, dy), vx=..., vy=..., omega=...)` sets a pending
-  target (validated against the applied offset: box, Euclidean step ≤ .5
-  cell, speed, no sliding hold); `vx`/`vy` are the interval wall velocity.
- `run(1)` advances a pending target and commits it only after the step
-  synchronizes with `no_donor == 0`; `run(n > 1)` with a pending target
-  raises; without a target `run(n)` holds the geometry (spin allowed).
-  Direct `LBMStepper.step` refuses while a target is pending.
- `moving_diagnostics()` returns per body the columns of
-  `MovingTables.DIAG` (CME, Wen term, link mass, cover/uncover momentum and
-  mass, eq_only, no_donor, crossings) accumulated since obs were zeroed;
-  `obs`/`read_force` keep their contract (CME on the body).
- `get_flags()` reads device flags back when moving circles exist.
- `snapshot()` / `restore()` save and restore populations only, keeping the
-  current clock, controls, observations, geometry and flags. Use them only
-  with unchanged geometry; restoring across a translation is unsupported
-  and is not rejected at runtime. They do not provide FSI rollback.
-
-*Supported:* dense double buffer, D2Q9, FP32 unshifted, SRT/MRT, circles,
-spin. *Rejected before mutation:* EsoPull, ddf shifting, D3Q19, refinement /
-blocked steppers, Jets or surface actuation on a moving circle,
-`sync_bodies` and checkpoints while a moving circle exists, swept bands that
-touch the domain edge, other bodies, sensors or force regions.
-
-*Failure lifecycle.* Device-side failures (upload, step, sync, no_donor)
-mark the Simulation failed; later run/step/sync/checkpoint calls and direct
-stepper calls refuse until `close()`.
-
-*Known limitations.* No mass correction at curved walls (static or moving);
-cover/uncover and Wen terms are diagnostics, not a selected force law; the
-host loop costs a fixed per-step synchronization (≈ 1 ms/step measured on a
-7.2 M-cell grid, run(1) class); outer boundaries are the single dense
-channel package (see `configs/CONFIG.md`).
-
-## Design record (staged contract, kept as written)
-
-The sections below are the contract the slices were reviewed against
-(S0 → S3a). They are kept unchanged for provenance; where they say "draft",
-"proposed" or "until S2/S3", the status above supersedes them.
-
-Original scope (Frank via TRON, thread C0C78UFKGRM/1793335557.460509):
-uniform-grid prescribed translation and single-cylinder free transverse VIV;
-base main `b2034f87e03656c5f67ab88562a70d6c338b9918`.
-
-## 1. Working standards
-
- Lean, readable kernels in the existing idiom (`kernels/step/*.cu`, shared
-  `apply_bouzidi_link`); Python manages state and validation. No framework,
-  no compatibility layer, no new dependency.
- The existing stationary/rotating path (`CurvedBoundaryKernel`, host link
-  packing, `sync_bodies`) stays byte-identical. Moving circles are a separate,
-  explicitly enabled path with its own numerical contract (this file).
- One authority per state (section 4). No per-step full-domain download,
-  rebuild or recompile; local swept-band device updates are in scope.
- Small slices (S1 host spec, S2 kernels without motion, S3 motion + refill,
-  S4 oscillator); each reviewed SHA is frozen before targeted runs.
- Tolerances, benchmark parameters and the force composition used in the
-  structural RHS are declared before the runs that judge them. Fresh vs carried
-  evidence and existing baseline failures are recorded; smoke, convergence and
-  physical validation are reported separately. No undeclared force filtering.
- External code (waLBerla GPLv3, FluidX3D source-available, VIVSIM) is a
-  concept reference only; nothing is copied.
-
-## 2. Current update order (main b2034f87, dense double buffer)
-
-`Simulation.run(n)`: upload host action (if `upload_act`) → zero obs (if
-`zero_obs`) → `DoubleBufferStepper.step(n)` → download obs → synchronize.
-
-Per step (`lbm/stepper.py` `step`):
-
-1. `CurvedBoundaryKernel` over the packed cut links: reads post-collision
-   `G^{n-1}` at `k_f` (and `k_f - c` for q < 1/2), adds the moving-wall term
-   (`Uw = -omega*ry, Vw = omega*rx` + optional per-link `surface_velocity`),
-   writes the reflected value into slot `opp` of the solid node `k_s`, and
-   accumulates `c(f_toward + f_reflected)` and torque into `obs`.
-2. `OneStep` pull/collide `ddf → temp` (collides FLUID cells; obstacle
-   interiors flagged `SOLID|OBSTACLE|BC_CURVED`), then buffer swap.
-3. `ForceRegionKernel`, `SensorKernel`.
-
-Raw `obs` force is the force **on the body** (link derivation in section 6;
-DFG docs report `Cd > 0` from it). Translation `vx, vy` in the action slots is
-currently stored but not read by any curved kernel.
-
-## 3. Proposed update order (moving circles)
-
-Per step n, before the existing step 1:
-
- **M1 `MovingCircleCells`** (one thread per swept-band cell): classify with the
-  analytic predicates `in_old = inside(x, c^{n-1})`, `in_new = inside(x, c^n)`;
-  write `flag = in_new ? SOLID|OBSTACLE|BC_CURVED : FLUID`; covered cells
-  (`!in_old && in_new`) accumulate `node_cover`; fresh cells
-  (`in_old && !in_new`) are refilled (section 5) and accumulate `node_uncover`.
- **M2 `MovingCircleLinks`** (one thread per band cell × direction): compute
-  q and hit point at `c^n` (FP64, same formula as `find_circle_intersection`,
-  same clamp [0.01, 1] and fallback classes as `CircleGeometry.build_cut_links`),
-  skip non-cut slots, call `apply_bouzidi_link` with
-  `u_w = (vx^n, vy^n) + omega × (hit - c^n)`, accumulate the link terms
-  (section 6).
-
-Then the unchanged steps 1–3. M2 must follow M1 because a q < 1/2 link may
-read `k_f - c` at a fresh cell.
-
-Exclusivity: moving bodies are never packed into the `CurvedBoundaryKernel`
-link arrays (`n_curved` covers stationary/rotating bodies only), so M2 is the
-sole writer of their solid slots and the sole source of their link force; no
-double write and no double `obs`. The stationary path's packing, launch and
-arithmetic are unchanged.
-
-Completeness: after M1, every (fluid cell, direction) pair in the swept band
-whose neighbour is `in_new` is visited by M2. This holds because the band is
-the circle AABB at the declared extreme offsets plus 2 cells, and the host
-rejects per-step moves with `|c_new - c_old|_2 > 0.5` and bands touching the domain edge,
-other bodies, sensors or force regions. Each M2 write lands at
-`index_f(k_s, opp)`, the exact slot the adjacent fluid cell pulls, so every
-fluid pull from a solid slot of a moving body is BFL-written.
-
-## 4. State, masks and authority
-
- Host `ObjectState` is the single authority for one displacement
-  `offset = (dx, dy)` relative to the immutable base centre, plus
-  `velocity = (vx, vy)` and `omega`. Centres are always derived
-  (`c = base + offset`), never stored as independent state. Velocity is
-  supplied, never differenced from offsets.
- `c^{n-1}` is derived from the last *committed* offset, `c^n` from the
-  offset being applied. Per body a small device **motion record**
-  `{c^{n-1}, c^n, u^n}` is uploaded with the action buffer; action-slot meaning
-  is not overloaded. (CANDIDATE layout; OPEN.)
- Fail-closed commit: an enqueued upload is not a completed one. The new
-  offset becomes the committed offset only after the stream synchronization
-  that follows the upload and the step group succeeds. Any upload or later
-  synchronization failure leaves host and device motion state unknown: the
-  simulation is marked unusable (existing `_require_usable` lifecycle), and
-  no API may report a host/device match afterwards.
-
-### 4a. Applied geometry vs pending target (CANDIDATE, narrow API)
-
-Two distinct facts per moving body, one authority each:
-`applied` = offset of the geometry last applied on the device, changed only
-by a successful commit; `pending` = an optional requested target
-`(offset, velocity)`, changed only by `set_body`. A setter returning proves
-nothing about the device. The uploaded motion record is derived each run:
-`{c_old = base + applied, c_new = base + (pending.offset if pending is not
-None else applied), u = pending.velocity if pending is not None else 0}`
-(explicit `is not None`, so a zero offset or zero velocity is a valid target). Translational wall velocity exists only on a step
-that advances to a pending target; a hold step (`c_old == c_new`) has
-translational `u_w = 0` (spin unchanged), so a non-advancing circle never
-acts as a sliding wall. One moving step consumes one target.
-
-| situation | contract |
-|---|---|
-| `set_body` target | validated against `applied` (box, `|Δc|_2 ≤ 0.5` cell, speed bound) before mutation; on success replaces `pending` |
-| target with `offset == applied` and nonzero translational velocity | `ValueError` before mutation (would be a hold step with sliding wall velocity) |
-| two setters before a run | last wins; each validated against `applied`, not against the earlier pending target |
-| `run(1)` with pending | upload record, step, sync; on success `applied := pending.offset` (applied stores only the offset), `pending := None` |
-| `run(1)` without pending | hold: `c_old == c_new`, no cover/uncover, links at `applied`, translational `u_w = 0` |
-| `run(n > 1)` with pending | `ValueError` before mutation (single-step-only moving API) |
-| `run(n > 1)`, no pending | allowed: hold for n steps, translational `u_w = 0`, spin only |
-| `run(0)` | no motion upload, no commit; `pending` kept |
-| validation failure | `ValueError`, nothing mutated, retry allowed |
-| upload/launch/sync failure after enqueue | simulation unusable; `applied` and `pending` are not reported as device truth; no re-entry |
-
-Displacement norm: Euclidean per-step `|c_new - c_old|_2 ≤ 0.5` lattice
-cells (declared bound; CANDIDATE value).
- Membership is never read from a flag that M1 is overwriting. The host
-  verifies at `add_body` that every swept-band cell has base flag FLUID, so the
-  band's base state is known without reading `flag_gpu`.
- `flag_gpu` is the device authority for band cells while a moving body
-  exists; the host flag mirror is stale for those cells and is not used.
-
-## 5. Refill of fresh cells (CANDIDATE)
-
- Stored time level: everything in `ddf` at M1 is post-collision `G^{n-1}`; the
-  refill writes all 9 slots at that same level, so every slot of a fresh cell
-  that the following pull or a q < 1/2 link may read is defined. Donor values
-  are read at the same level `G^{n-1}` (old-fluid cells, untouched by M1).
- `G = f_eq(rho_bar, u_w(x)) + G_neq(x_d)` where `rho_bar` = mean density of
-  valid neighbours and `x_d` = the valid neighbour best aligned with the outward
-  normal `(x - c^n)/|x - c^n|`; `G_neq(x_d) = G(x_d) - f_eq(rho(x_d), u(x_d))`.
- Valid donor: inside the domain, base FLUID, `!in_old && !in_new`.
- Sets: `V(x)` = the 8 lattice neighbours that are in the domain, base FLUID
-  and `!in_old && !in_new`. `rho_bar` = mean density over `V(x)`. NEQ donor =
-  the member of `V(x)` with the largest `c·n` among those with `c·n > 0`
-  (`n` = outward normal at `c^n`); none → NEQ part 0 (counted as `eq_only`).
- `V(x)` empty → no defined density: the cell is refilled with
-  `f_eq(RHO, u_w(x))` so all 9 slots stay defined, the `no_donor` counter is
-  incremented, and the host treats `no_donor > 0` after the run as a hard
-  failure (simulation unusable). It is not a silent fallback.
- Non-emptiness is NOT assumed from the displacement bound. Geometry
-  assumptions: circle radius `R ≥ R_min` (CANDIDATE 4 cells), `|Δc|_2 ≤ 0.5`.
-  S1 includes a host enumeration over sub-cell centre positions and
-  displacement directions on a fine grid within these bounds that checks every
-  fresh cell has nonempty `V(x)`; it is evidence for those bounds, not a
-  proof, and runtime keeps the counter.
- Fresh cells only write, old-fluid cells only read: no race.
-
-## 6. Discrete momentum ledger (to review; not a selection)
-
-Notation per step n: `F^n` = fluid set after M1; links L = (k_f, dir) at
-`c^n`; `f_t = G_dir(k_f)`; `f_r` = value M2 writes into `(k_s, opp)`.
-Fluid momentum before streaming:
-
-    P_pre = P(G^{n-1} on F^{n-1}) - sum_cover sum_q c_q G_q + sum_fresh sum_q c_q G_q^refill
-
-During the pull, every population entering a fluid cell comes from a fluid
-cell except the BFL-written slots; `f_t` leaves into solid and is never pulled
-by a fluid cell. Collision conserves momentum for SRT/MRT without forcing.
-Hence, in exact arithmetic,
-
-    P_fluid^n - P_fluid^{n-1} = - sum_L c (f_t + f_r) - I_cover + I_uncover + B^n + S^n
-
-with `B^n` external-boundary momentum (inlet/outlet/walls) and `S^n` forcing.
-So **`F_CME + node_cover - node_uncover`** is, by construction, the body
-momentum that balances the fluid ledger of *this* storage/update order.
-Branch details: halfway fallback links (`f_r = f_t` plus the moving-wall
-addend) and q < 1/2 links enter the link accumulators exactly like Bouzidi
-links, with `c(f_t + f_r)`. In the q < 1/2 branch `G_dir(k_f - c)` is an
-interpolation input only, not a fluid-momentum sink. Pull-slot completeness
-is the section 3 contract. The scope excludes `ddf_shifting` (rejected), so
-the unshifted force form applies. The balance is a fluid-side identity; it
-does not close body+fluid globally in a domain with inlet/outlet/forcing
-(`B^n`, `S^n`), and the solid-slot writes are boundary plumbing, not physical
-streaming packets.
-
-The Wen 2014 relative-velocity link sum adds `-u_w (f_t - f_r) = u_w dm` per
-link (`dm = f_r - f_t`, the BFL mass defect). That term has no counterpart in
-the fluid ledger above. Peng et al. (PRE 2016 submitted, §II.C, Eqs. 20–21)
-show for a straight wall that the bounce-back error accumulated before a node
-switch cancels with the switching momentum. Whether `sum u_w dm` approximates
-`I_cover - I_uncover` here (implying double counting if both are used) is
-**NOT demonstrated** for this implementation: it needs a bounded experiment
-(prescribed slow translation; cumulative `sum u_w dm` vs cumulative node
-impulse, per crossing cycle). Momentum conservation is also distinct from
-Galilean invariance, which G4 tests.
-
-External reference note: waLBerla's covered/refill momentum switches
-(`conserveMomentumWhenMapping`, `conserveMomentumWhenRestoring`) default to
-false (Astra), so their existence does not establish which combination its
-validation cases use. A bookkeeping identity alone does not select the
-physical force either.
-
-Mass ledger (same proposition status). With `M^n` the active-fluid mass
-summed over `F^n` at the sample point,
-
-    M^n - M^{n-1} = sum_L dm - m_cover + m_uncover + B_m^n
-
-(`dm = f_r - f_t`, `m_cover`/`m_uncover` = summed `sum_q G` of covered and
-refilled cells, `B_m` external-boundary mass flux; collision conserves mass).
-
-Sample point (fixed): post-collision storage after the swap of step n, i.e.
-the same level `G` that M1 reads at step n+1; both ledgers are evaluated
-there. Ledger residual = left side minus every listed term. Zero mass flux
-does not imply zero momentum exchange: closed walls (bounce-back, free-slip)
-still exchange momentum, so "no inlet/outlet, no forcing" does NOT give
-`B = S = 0`. The rounding-level momentum check therefore uses either a
-momentum-isolated case (periodic in both directions, no forcing) or counts
-the wall impulse explicitly as part of `B`; the mass check may use a closed
-domain. Otherwise `B`, `S` are not separately measured, the residual is
-reported as their estimate and is not a pass criterion.
-Both ledger identities are **proposed, unreviewed**: they are not called
-proven until review and a host replay agree.
-
-Accumulators (separate, per body, per step window; all reported raw):
-`link_cme`, `link_wen_correction` (= `sum u_w dm`), `node_cover`,
-`node_uncover` (momentum), `link_dm`, `mass_cover`, `mass_uncover` (mass),
-plus counters of crossings, `eq_only` and `no_donor`, so force spikes can be
-correlated with crossing events.
-
-**OPEN — structural RHS candidates (not selected):**
-(a) `link_cme + node_cover - node_uncover`; (b) `link_cme + link_wen_correction`
-(no node impulse). Selection follows the ledger review and the bounded
-experiment above.
-
-## 7. Rejection semantics
-
- Before any mutation (`ValueError`, no device write, host state unchanged):
-  moving body with EsoPull, `ddf_shifting`, refinement/blocked stepper, D3Q19,
-  Jets or surface actuation on that body, `sync_bodies`/checkpoint while a
-  moving body exists; swept band touching domain boundaries, other bodies,
-  sensors or force regions; `set_body` offset outside the declared box,
-  per-step move `|c_new - c_old|_2 > 0.5` cell (the single bound of 4a), speed
-above the declared bound.
- Host motion state is committed only after the upload *and* the following
-  synchronization of the step group succeed (section 4); any failure in
-  between makes the simulation unusable and no host/device match is reported.
- The only soft device diagnostic is `eq_only` (NEQ part omitted, counted).
-  `no_donor > 0` is a hard failure: it is checked after the step group and
-  before the step is committed or any results are returned; on failure the
-  simulation is unusable (section 5).
-
-## 8. Coupling and units (CANDIDATE)
-
-Lattice units, rho0 = 1, per unit span. Step n uses `c^n`, `u^n` and yields
-`F^n`. Weak staggered update
-`v^{n+1} = v^n + (F^n - c v^n - k y^n)/m`, `y^{n+1} = y^n + v^{n+1}`
-(Newmark is an alternative; OPEN). Mass, natural frequency, damping and `U_r`
-follow the chosen benchmark's own definitions. Leontini, Thompson & Hourigan,
-JFS 22:857–864 (2006), DOI 10.1016/j.jfluidstructs.2006.04.003, as read by
-Grok from the full text: Re = 200, `m* = m/m_f = 10` (m_f displaced fluid
-mass), `zeta = c/c_crit = 0.01`, `U* = U/(f_N D)` with `f_N` the natural
-frequency in fluid assuming an inviscid added-mass term; the paper also
-reports frequencies normalised by the in-vacuo value. Our runner derives `k`
-from that in-fluid `f_N` (added-mass coefficient as stated in the paper) and
-never from the vacuum formula; `c_crit` convention and the original
-comparison data are still OPEN. Stability/convergence is gated by fluid
-time/space refinement of the coupled run, not assumed from the mass ratio;
-structural sub-stepping does not substitute for fluid-coupling time
-refinement.
-
-## 9. Gates (map; tolerances OPEN, declared before runs)
-
-G0 zero-motion regression, split: G0a populations of the existing stationary
-and spin-only path bitwise unchanged vs main; G0b moving path at rest (with
-and without spin) reproduces the stationary link set and populations; force
-estimator outputs are compared separately from populations, since the moving
-path adds estimator terms · G1 raw force sign (`Cd > 0`) ·
-G2/G3 prescribed translation incl. ledger accumulators · G4 matched
-relative-flow (moving body in quiescent fluid vs fixed body in uniform
-stream), optional boost, co-moving sanity · G5 Dütsch et al. 1998 Re 100,
-KC 5 in-line (needs 2-component offset) · G6 Leontini free transverse VIV
-(m* = 10, ζ = 0.01, Re = 200, definitions pending) · G7 time-level contract
-frozen before the oscillator.
-
-Candidate pre-run engineering tolerances (Astra; for discussion, not
-literature limits or measured outcomes; norms, averaging window, convergence
-protocol and physical reference uncertainty must be fixed before adoption, and
-none may be weakened after seeing runs):
-normalised momentum-ledger residual FP32 ≤ 5e-6 (FP64 oracle ≤ 2e-13);
-10-cycle relative mass drift ≤ 1e-4; prescribed-motion grid study D = 40/80/160
-with change in the force-response amplitude (observed quantity and norm to be
-named before adoption) ≤ 2 % and phase ≤ 2°; enlarged domain
-amplitude change ≤ 1 %; matched-frame force RMS ≤ 2 % and improving with
-refinement; VIV refinement amplitude ≤ 2 %, frequency ≤ 1 %, five consecutive
-cycle amplitudes within 1 %.
-
-Conditions stated before any moving kernel (S2/S3), not only at the
-oscillator stage: (i) fluid refinement protocol for the prescribed-motion
-gates — diffusive scaling (dx halved, dt quartered, physical Re, KC and
-amplitude fixed), the observed quantities and norms named in advance;
-(ii) Galilean constant-boost G4-boost requires boundaries compatible with a
-uniform boost (periodic in the boost direction or boundaries that move with
-it); if the current dense configuration cannot represent that, G4-boost is
-recorded as not runnable rather than replaced by another test.
-
-## 10. Proposed minimal S1 scope (host only; held until cross-review)
-
- `add_body` moving-circle declaration: base centre, declared offset box
-  (x/y), speed bound; swept-band computation and band-placement validation.
- `set_body(offset=..., velocity=..., omega=...)` validation before mutation
-  (section 7), applied/pending state and the run-transition table of 4a,
-  and the fail-closed commit of section 4.
- Host enumeration check of refill-donor non-emptiness (section 5) within
-  the declared `R_min` and displacement bound.
- Motion-record host layout and upload path; exclusion of moving bodies from
-  the packed `CurvedBoundaryKernel` links (stationary packing unchanged).
- Explicit rejections for unsupported modes.
- S1 execution guard: until the S2 moving kernels exist, any `run(n)` with
-  `n > 0` (and `step(n)`) while a moving body is declared raises before any
-  device mutation (no action/motion upload, no launch), including the
-  nominal at-rest case, because the moving body is excluded from the static
-  packed links and nothing else would apply its boundary. `run(0)` keeps its
-  existing behaviour. Simulations without moving bodies are unaffected.
-  Preparation/commit helpers are exercised by host tests with mocks; no
-  operational unsupported stepping path is exposed.
- Host tests (Astra runs them): rejection-before-mutation, band geometry,
-  derived centres, fail-closed behaviour under an injected upload/sync
-  failure, stationary packing byte-identical, execution guard (positive-step
-  run with a moving body raises before upload/launch; stationary unaffected). No kernels, no GPU runs, no
-  y-only VIV oscillator (S4), no force RHS.
-
-## 10a. S2a — fixed-centre moving links (implemented on `claude/moving-bodies-s2a`)
-
- `MovingCircleLinks` (`kernels/step/moving_circle.cu`, dense double buffer)
-  runs before the static curved kernel when moving tables are attached: one
-  thread per (band cell, direction) slot, FP64 `{cx, cy, r}` at the applied
-  offset, q/hit/clamp/fallback in the order of `build_cut_links` with explicit
-  `_rn` operations (host/device bit parity is a test target, not a claim),
-  then the unchanged `apply_bouzidi_link` with spin wall velocity only.
- `obs` keeps its contract (CME and torque from `apply_bouzidi_link`). A
-  separate per-body diagnostics buffer receives `cme`, the Wen term
-  `u_w * dm`, `link_dm` and the link count from the same link outputs; it is
-  zeroed with obs and only exists when moving circles do. Optional
-  `slot_debug` (q, fallback, rx, ry per slot) is null in production.
- Displacement is disabled: `set_body(offset=..., vx=..., vy=...)` on a
-  translating circle raises before mutation, before and after initialize, so
-  no pending target can exist and `run`/`step`/direct `LBMStepper.step` all
-  hold at the applied geometry. `initialize()` never reads or consumes
-  `pending`. `stepper.blocked` is cleared only when the moving tables are
-  attached (initialize, stepper recreation).
- S3 rule (not implemented): once targets are re-enabled, any pending target
-  must raise in `run`/`step` and in `LBMStepper.step` alike before any launch,
-  swap or step-count change; zero-step calls never consume it.
- Not validation: a pass of the zero-motion gates says nothing about moving
-  geometry. GPU parity (G0a/G0b) is unverified until run on a free device.
-
-## 10b. S3a — translation with refill (implemented on `claude/moving-bodies-s3a`)
-
- Targets are enabled again (4a). `set_body(offset, vx, vy)` validates against
-  `applied`; a pending target blocks direct `LBMStepper.step(n > 0)` before any
-  launch; `run(n > 1)` with a target raises before mutation; `run(0)` never
-  consumes it; `run(1)` advances it.
- Per advancing step, on one stream: upload the immutable FP64 records
-  `{c_old, c_new, r, u}` (only when changed) → M1 `MovingCircleCells` → M2
-  `MovingCircleLinks` (`u_w = u + omega x r` at the hit point) → static curved →
-  `OneStep` → swap → force region → sensors → synchronize → read `no_donor` →
-  commit (`applied := pending.offset`) → upload the hold record
-  (`c_old = c_new = applied`, `u = 0`) → synchronize. Hold steps launch no M1
-  and are the S2a path. Commit point: the advancing step-group sync plus a
-  zero `no_donor` count; a failure before it commits nothing. The hold-record
-  upload stages the next step after the commit: if it (or its sync) fails,
-  `applied` already matches the moved device geometry, but the Simulation is
-  still marked failed and refuses reuse. Any failure from the first upload on
-  marks the circles and the Simulation failed.
- M1 classifies with the old/new predicates only (no flag reads). Covered
-  cells add raw `sum c G` / `sum G` of `G^{n-1}` to `cover_*` and become
-  `SOLID|OBSTACLE|BC_CURVED`. Uncovered cells: donors are fluid in both
-  geometries; `rho_bar` over all of them; NEQ from the donor with the largest
-  unnormalized `c·n > 0` (first direction wins ties, `n` from `c_new`);
-  `u_w` (translation + spin) at the cell position; all nine slots written;
-  raw `sum c G`, `sum G` of the refill go to `uncover_*`; no donor →
-  `f_eq(RHO, u_w)` plus `no_donor` (hard failure before commit); no NEQ donor
-  → `eq_only`.
- `get_flags()` reads the device flags back (synchronized) when moving tables
-  exist; otherwise it returns the host array as before.
- Not selected: the structural force. CME+node vs CME+Wen stay OPEN until X1
-  and G4 have run.
-
-## 11. Remaining decisions
-
-Structural RHS (section 6); motion-record layout; refill details; coupling
-scheme; benchmark definitions and digitized reference data; tolerances;
-execution/resource feasibility (Astra, pending); whether a quiescent domain
-(zero inlet velocity) runs cleanly in the current config.
@@ -1,99 +0,0 @@
-# Moving-boundary force spikes: evidence and source index
-
-Updated 2026-10-31.
-
-This note indexes supplied audited observations and primary-source extractions.
-It does not report a newly measured cure or implement an alternative method.
-Paper details below were supplied by the parent investigation; no new source
-retrieval or independent paper verification was performed for this note.
-
-## Current implementation and interpretation
-
- Celeris M1 reconstructs a fresh node as `feq(rho_bar, u_wall) + donor NEQ`.
- In exact arithmetic, the donor non-equilibrium component has zero mass and
-  momentum when formed against the donor's own equilibrium moments.
- Re-projecting that same reconstruction onto the same wall velocity therefore
-  does not, by itself, change its mass or momentum or supply a cure for spikes.
- Floating-point residuals should be measured separately from this algebraic fact.
- Peng's alternative differs upstream: extrapolate PDFs from three donors, then
-  replace selected moments. It is not simply another projection of current M1.
- PPO interval-force observations and native per-step FSI right-hand-side forces
-  are distinct signals; comparisons must identify which signal is being used.
-
-## Audited run observations supplied to this note
-
- D40 revision: `e9213dd2cc9cfed0e8487a3cf4ebdd94d23dc64d`.
- Window: first `97.303 D/U` of physical time.
- Maximum displacement: `max |y|/D = 0.304893`.
- Maximum native force-coefficient increment: `max |ΔCy| = 0.66688`.
- D20 over the same physical-time window: `max |ΔCy| = 1.80735`.
- The largest D40 event involved 30 nodes.
- These are supplied audited observations, not measurements made for this note.
- Time steps and trajectories differ between runs. This comparison establishes
-  neither spatial convergence nor a unique cause for the force spikes.
-
-Evidence locations supplied by the investigation:
-
- Horsea: `/tmp/celeris-results-pinball-resolution`.
- Mac: `validation-evidence/pinball-force-diagnosis`.
-
-These locations index run evidence, not local copies of the cited papers.
-
-## Tao, Hu, and Guo (2016): time-step decoupling
-
-Computers & Fluids **133**, 1–14. DOI:
-[10.1016/j.compfluid.2016.04.009](https://doi.org/10.1016/j.compfluid.2016.04.009).
-[Publisher abstract](https://www.sciencedirect.com/science/article/pii/S0045793016301116).
-
- Abstract-level support only: non-equilibrium refill reduces oscillations.
- With local iteration, the compared refill methods give similar oscillation magnitudes.
- Time-step decoupling reduces oscillations further in the reported sedimentation,
-  Couette, and Poiseuille examples.
- The exact decoupling schedule and time-step ratios have not been verified.
- This abstract does not establish equivalence to an arbitrary force filter.
- Do not implement a claimed reproduction until the actual methods are available.
-
-## Marson et al. (2021): local iterations
-
-Physical Review E **103**, 053308. DOI:
-[10.1103/PhysRevE.103.053308](https://doi.org/10.1103/PhysRevE.103.053308).
-[Open repository record](https://archive-ouverte.unige.ch/unige:151868).
-
- §VI, p. 18 discusses pressure waves associated with fresh nodes.
- Appendix E.3, p. 25 and Fig. 18, p. 24 describe the local procedure.
- Copy a local sublattice, perform local collision and streaming, write the fresh
-  nodes, and repeat before the global collision and streaming operation.
- One to three iterations performed best in the reported tests; this is not a
-  universal iteration-count recommendation.
- The reported smoothed torque-noise assessment is qualitative here.
- Its thin-shell setting differs from the current moving-body configuration.
-
-## Peng (2016): extrapolation and moment replacement
-
-Computers & Mathematics with Applications **72**, 349–374. DOI:
-[10.1016/j.camwa.2015.08.027](https://doi.org/10.1016/j.camwa.2015.08.027).
-
- §5.1.2, Eq. (50), p. 368: extrapolate PDFs along an outward normal direction:
-  `f_new(x) = 3 f(x + e) - 3 f(x + 2e) + f(x + 3e)`.
- §5.1.3, Eq. (51): wall equilibrium plus donor non-equilibrium is the family
-  containing the current M1 reconstruction.
- §5.1.4, Eqs. (52)–(54): in MRT space, replace momentum with `j = rho0 u_wall`,
-  preserve the other moments, then apply the inverse transform.
- A compressible Celeris adaptation must choose the appropriate density;
-  copying the paper's `rho0` blindly is not justified.
- Three valid donors require new eligibility checks and fallback behavior beyond
-  the current one-link shared-body clearance rule.
- §§5.2–5.3 retain nonzero fluctuations in specific configurations; these results
-  do not promise elimination of force spikes in the present problem.
-
-## Bounded next investigation
-
-1. Retain current M1 as the baseline and compare matched prescribed trajectories
-   over matched physical-time windows.
-2. Record raw force RHS, node crossings, donor moments, mass and momentum changes,
-   impulse, spectra, and trajectory response together.
-3. Evaluate local iterations, Peng-style reconstruction, and force filtering as
-   separate interventions, with explicit definitions and diagnostics.
-4. Obtain the actual time-step-decoupling methods before implementing that method.
-
-The current task indexes evidence only; it makes no alternative-method change.
@@ -1,150 +0,0 @@
-# Uncontrolled steady pinball: development protocol
-
-Frozen before results: 1280 x 512 D2Q9/FP32/MRT, unshifted double buffer;
-rho=1, mean U=.01, nu=.004, D=20, Re_D=50. Centres are (600,255.5),
-(626,270.5), (626,240.5), radius10. No upstream cylinder. Passive probes stay
-at (800,295.5), (800,255.5), (800,215.5), radius5. Every omega is zero.
-Parabolic inlet, regularized NEQ damping1; y bounce-back planes .5/510.5;
-NEQ-extrapolated outlet with backflow clamp (the configured blend is inactive in
-this MRT route). Initial fluid is
-parabolic equilibrium. Fixed warmup is 4 NX/U=512000 steps.
-
-Geometry and fluid parameters follow DynamisLab 609116ec26f19766f5e9ce2b0df427d4e24faae8,
-`legacy_test/core/legacy_env_builder.py:build_steady_cloak` and the retained
-`config_lbm_pinball_legacy_re50d_u001.json`. This is a modern Celeris reconstruction,
-not a bitwise Legacy reproduction: Legacy uses shifted incompressible MRT, a
-different curved interpolation and prescribed parabolic outlet velocity. Current
-Celeris uses standard MRT, two-branch BFL and extrapolated outlet velocity.
-The fixed-hold control uses the SAME modern settings as the free case.
-
-## Shared translation and ownership
-
-`Translation(..., shared=True)` is explicitly transverse only. Reusing one
-envelope INSTANCE declares common motion; equal but separate envelopes are not
-linked. Before initialization and every positive Simulation.run, group members
-must have identical applied offsets, effective target offsets and interval wall
-velocities. Stage each member with set_body, then call run(1) once. An incomplete
-or inconsistent target group is rejected before device uploads and can be fixed.
-Existing pending-target direct-stepper restrictions remain.
-
-Only members of that group may have overlapping whole swept bands. Their fixed
-surface clearance must exceed4 lattice cells. This conservative bound exceeds
-2 sqrt(2)+MAX_STEP = 3.329: M1 changed cells lie in old/new disks and read one-link
-neighbors; M2 reads at most two links outside its new disk. Old/new relative
-displacement is at most .5. Thus reads cannot reach another member's old/new
-solid or M1 write region. M1 writes are disjoint. M2 writes opposite population
-slots inside its own new disk, also disjoint. Separate first_slot ranges still
-allocate each body's logical band/debug storage. Shared band cells alone do not
-write anything: M1 returns unless membership changes; M2 returns unless a cut
-link exists. Unrelated moving/static body and probe overlaps still reject.
-
-This is a sufficient restricted-group condition, not support for near-contact
-or independent motion. The r4, distance8.3, dy=.5 counterexample remains rejected.
-CPU tests enumerate candidate donors/write footprints over subcell phases;
-GPU tests compare fixed vs hold and member-order permutations through crossings
-at wall speed .01 over the full +/-D envelope (8000 steps). The initial .5-speed
-fixture failed with NaNs; a single-circle control also failed at step69. That
-Mach~.866 fixture was unsuitable as a low-Mach numerical gate. Its failure is
-retained; the geometric MAX_STEP proof is unchanged, not a stability guarantee.
-CUDA kernels and arithmetic are unchanged.
-
-## New structural parameters (not inherited from the paper)
-
-One transverse state y,v; total assembly M=10 rho (3 pi D^2/4)=9424.77796,
-fn=U/(5D)=.0001, Tn=10000, zeta=.01, K=M(2 pi fn)^2,
-C=2 zeta M(2 pi fn). Initial y=v=0, no seed or later kick. Force is the sum
-of the three instantaneous CME_y+Wen_y values from the previous fluid step;
-node impulses are logged separately and never added. The damped oscillator is
-integrated exactly for that piecewise-constant force over dt=1. Wall velocity
-is y[n+1]-y[n], not the endpoint oscillator velocity. No filtering or retuning.
-
-Observe600000 steps=60Tn=300 D/U after warmup, in each of free and fixed-hold
-cases. Final20Tn is a descriptive comparison window; ten-Tn blocks expose drift.
-No settled/periodic claim follows merely from reaching the cap. Stop on |y|>D,
-nonfinite values, no_donor, rejected displacement or speed>.05. Report any quiet
-response honestly. No automatic extension. --smoke uses32 warmup+32 steps only.
-
-Native-step rows retain y,v, each body's CME/Wen/node terms and refill counters;
-each600000x15 FP64 file is72MB. No full-field output or policy training. Compile
-and run on one device serially, keep original outputs and dirty trees untouched.
-This stage makes no claim of physical grid convergence or vibration suppression.
-
-Run from checkout with PYTHONPATH=src and the existing Python environment:
-`python research/steady_pinball/run.py --smoke --out <new-external-directory>`
-then separately `--out <new-free-directory>` and `--fixed --out <new-fixed-directory>`.
-
-## Zero-damping development follow-up (predeclared 2026-10-31)
-
-The original d0bcefa run and its zeta=.01 results remain historical evidence.
-The current runner exposes three fixed `--case` choices, all with C=0 as requested:
-
-| Case | M / (rho 3 pi D^2/4) | fn | M | K | Purpose |
-|---|---:|---:|---:|---:|---|
-| Z0 | 10 | .0001 | 9424.77796 | .00372075320 | Remove damping only |
-| M2 | 2 | .0001 | 1884.95559 | .000744150640 | Reduce mass and stiffness together at fixed fn |
-| R2 | 2 | .00006 | 1884.95559 | .000267894231 | Change stiffness only relative to M2 |
-
-R2 deliberately places fn at the retained fixed-body lift peak, f=.00006
-(St=.12 on mean U). This is an informed development choice, not independent
-physical validation or a promise of lock-in. All geometries, fluid settings,
-512000-step fixed warmup, y0=v0=0, force time level and unfiltered RHS are unchanged.
-No run result may select a replacement parameter or an automatic extension.
-
-Each case has a 600000-step cap, the same 300 D/U physical duration. This equals
-60 natural periods for Z0/M2 and 36 for R2. Compare the common final200000 native
-steps, and six100000-step blocks, retaining actual natural/response frequencies
-and ongoing drift. Do not call those blocks ten R2 periods. No settled-VIV claim
-follows from a larger displacement. Report all three outcomes, including quiet
-responses or stopped cases, alongside the existing fixed and damped-free records.
-
-Unchanged stops: |y|>D, invalid move/speed, nonfinite values or no_donor. A 1800s
-per-case wall cap and GPU headroom check bound resource use. Preserve partial rows;
-do not add damping, clip trajectories, filter forces, or relax any stop. Each
-case adds72MB of scalar history, no full fields. The separate Legacy/modern
-baseline diagnosis does not change this FSI protocol.
-
-## Matched D40 resolution comparison (predeclared 2026-10-31)
-
-The first finer case is M2, with exactly the same mass ratio2, reduced velocity5,
-zero structural damping, initial rest state and physical geometry as the retained
-D20 M2. Targeting a development response of0.5--1D does not imply this case will
-reach it. Do not change the structure within this comparison or discard a smaller
-response. D60 is a supported scaling choice, not an automatically scheduled run.
-
-For s=D/20 use dx'=dx/s, dt'=dt/s^2, U'=.01/s, nu'=.004, rho'=1,
-fn'=fn/s^2, M'=s^2 M and K'=K/s^2. The same physical force per unit span
-has F'_lat=F_lat/s. For D40 this gives U=.005, fn=.000025,
-M=7539.82237, K=.000186037660, Re_D=50, and Tn=40000 steps.
-The y walls are at .5 and ny-1.5, while x inlet/outlet source nodes are at0
-and nx-1. Therefore map x'=s*x and y'=.5+s*(y-.5), with
-nx'=s*(1280-1)+1, ny'=s*(512-2)+2. D40 uses2559x1022 and centres
-(1200,510.5),(1252,540.5),(1252,480.5); every radius, probe and envelope scales
-with D. The parabolic profile retains the same normalized wall coordinate.
-This preserves the existing ghost-source boundary convention, without asserting
-that it is an exact continuum open-boundary location.
-
-Warmup=2048000 and response=2400000 native steps at D40: the SAME256 and300
-D/U durations as D20, including60 natural periods after release. Compare the
-six50-D/U blocks and the common final100-D/U window. Report max absolute y/D,
-half-range, RMS, frequency and drift; peak-to-peak is not amplitude. No settling
-claim follows from completion. Keep raw individual CME/Wen/node terms and all
-crossing/fallback counters. Normalize net force by .5*rho*U^2*D in each case.
-Report native crossing/non-crossing force increments separately, plus D40
-four-step block means aligned with D20 intervals (diagnostic only, never replace
-the raw spikes). Report final-window high-frequency variance above f*D/U=1,
-using demeaned FFT Parseval weights, with the same physical cutoff for both cases.
-Different motion histories confound spike-size comparisons; this is simultaneous
-space/time/Mach refinement, not proof of a unique coarse-grid cause.
-
-Only one full D40 M2 is initially scheduled, after CPU checks and a32+32-step
-smoke. Stop on the unchanged geometry/speed/nonfinite/no_donor checks or a7200s
-whole-case wall cap; save completed rows and status. The velocity cap scales to
-.025 so its physical bound is unchanged. No force filtering, trajectory clipping,
-automatic parameter search or extension. Scalar history is288MB; no full fields
-or DDF snapshots are written. Two FP32 population buffers require about188MiB,
-before flags, moving tables and context overhead; measure actual peak usage in
-the smoke and full run. Keep all D20 outcomes. No production source changes.
-
-Commands (one GPU and serial compilation, existing environment):
-`python research/steady_pinball/run.py --case M2 --D 40 --smoke --out <new-smoke-dir>`
-then `python research/steady_pinball/run.py --case M2 --D 40 --wall-seconds 7200 --out <new-full-dir>`.
@@ -1,96 +0,0 @@
-# Supported settings: 2D Jet + fixed multilevel refinement (candidate 888c8038)
-
-Every entry names the guard that enforces it (file and function or kernel guard,
-at source revision 888c80381c006e976be2af8a452288729fc17c1b) and, where one
-exists, an existing test that exercises it. A setting not listed here is not
-claimed. Observations at the end are tied to the exact case in which they were
-measured; they are not general bounds.
-
-## Lattice, storage, collision
-
-| Setting | Supported | Guard |
-|---|---|---|
-| Dimension / lattice | 2D D2Q9 only (3D refinement is future work) | `lbm/refinement.py` `FixedPatch2D.from_config`; `#error` guards in `lbm/kernels/blocked.cu` |
-| Precision / streaming | FP32 storage, double buffer | same guards |
-| Collision on refinement levels | SRT or MRT; TRT and LES rejected | `lbm/refinement.py` `FixedPatch2D.from_config` (re-checked for fine boundaries in `prepare_fine_boundary`) |
-| Shifted (ddf_shifting) storage | supported (every level is blocked); one representation on all levels | `lbm/refinement_stepper.py` `FixedPatchStepper._check_storage` |
-| Fine relaxation | 1/tau_fine must lie inside the configured omega guards | `lbm/refinement.py` `FixedPatch2D.from_config` |
-| Single blocked level `FixedPatchStepper(refinements=[], level_blocks=[(by, bx)], level_objects=[circles])` (replaces `PeriodicBlockStepper`, removed in 8e1feff) | doubly periodic, SRT only, no LES/Jets/projection/exchange observation, stationary passive circles; `download()` returns a 1-tuple | `lbm/refinement_stepper.py` `_check_levels`, `FixedPatchStepper.__init__`; `lbm/blocks.py` `static_circle_tables` |
-| Refinement storage | blocked on every level: `level_blocks` is required, one tile `(by, bx)` per level dividing that level; a whole-level tile (`(ny, nx)` at the root, the fine window shape for one rectangle) always divides. Dense and mixed dense/blocked storage were removed (parity of D/D, D/B and B/B recorded at 1573942 and 2469af7) | `lbm/refinement_stepper.py` `_check_levels`, `FixedPatchStepper.__init__` |
-
-Tests: `tests/unit/test_refinement_mrt.py`, `tests/validation/multigrid/test_refinement_mrt_gpu.py`,
-`tests/unit/test_shifted_storage.py`, `tests/unit/test_shifted_block_operators.py`.
-
-## Refinement hierarchy (`FixedPatchStepper(cfg, *, context, refinements, ...)`)
-
-| Setting | Supported | Guard |
-|---|---|---|
-| Depth | at least one refinement level; one entry per level in `level_blocks`/`level_objects`/`level_jets` | `lbm/refinement_stepper.py` `_check_levels` |
-| Single L1 rectangle | two-coarse-cell margin to the domain edge | `lbm/refinement.py` `FixedPatch2D.from_config` |
-| Several L1 rectangles (union) | require `level_blocks[0]` and `level_blocks[1]`; transfers must close (dependency checks, no fixed gap rule) | `lbm/refinement_stepper.py` `_check_levels`; `lbm/refinement.py` `_check_parent_pull_closure` |
-| Nested levels | depth >= 3 must be all blocked; a blocked level requires blocked levels below; a scalar child needs a scalar parent | `lbm/refinement_stepper.py` `_check_levels`; `lbm/hierarchy.py` `build_hierarchy` |
-| Nested transfer support | child only over inherited ACTIVE cells, donors/receivers uncovered ACTIVE, no child over the parent restriction footprint | `lbm/refinement.py` `_nested_kind` |
-| Tile shape | positive `(by, bx)`; the level allocation must be divisible by the tile (no partial tiles yet) | `lbm/refinement_stepper.py` `_check_levels`, `lbm/refinement.py` `FixedPatchSet2D.fine_layout` (shape); `lbm/blocks.py` `BlockLayout2D.build` (divisibility) |
-| Coarse boundary | `periodic`, `slot_reservoir` or `channel` | `lbm/refinement_stepper.py` `FixedPatchStepper.__init__` |
-| `slot_reservoir` | on-site velocity bottom slot, reservoir top, velocity 0, 2 <= slot width < nx, patch rows 4..ny-4 | `lbm/refinement_stepper.py` `FixedPatchStepper.__init__`; `lbm/refinement.py` `prepare_fine_boundary` |
-| `channel` | all levels blocked; Zou-He inlet, pressure-NEQ outlet, stationary bounce-back walls; transfers away from the closure | `lbm/channel.py` `validate_channel_config`, `validate_channel_transfers` |
-| Explosion | `constant` (default); `projected_linear` only periodic, all-blocked SRT, no bodies/Jets, no LES (experimental) | `lbm/refinement_stepper.py` `FixedPatchStepper.__init__` |
-| L2 runtime remap (`remap_finest`) | periodic three-level L2 sets only, no L0/L1 bodies, identical pinned boundary | `lbm/refinement_stepper.py` `FixedPatchStepper.remap_finest` |
-
-Tests: `tests/unit/test_refinement_three_level_multipatch.py`, `tests/validation/multigrid/test_refinement_multipatch.py`,
-`test_refinement_three_level.py`, `test_refinement_three_level_multipatch_gpu.py`, `test_refinement_blocked_base.py`,
-`test_refinement_blocked_fine.py`, `test_channel_root_gpu.py`, `tests/unit/test_channel_root.py`,
-`tests/unit/test_projected_pair_stepper.py`, `test_runtime_child_remap_gpu.py`, `test_pinned_body_remap_gpu.py`.
-
-## Bodies and Jets on refined levels
-
-| Setting | Supported | Guard |
-|---|---|---|
-| Bodies | stationary circles without sensor/force-region roles, entirely inside the patch union, fully resolved, disjoint, stencil away from the two-hop transfer footprint | `lbm/refinement.py` `prepare_fine_boundary` |
-| Level | not on L0; only on the finest level of a nested hierarchy | `lbm/refinement_stepper.py` `_check_levels` |
-| Jet condition | velocity only; `pressure` is reserved and raises NotImplementedError | `body/jets.py` `Jet.__post_init__` |
-| Jet geometry | each Jet selects resolved links of exactly one stationary body; no Jet/Jet or Jet/SurfaceActuation overlap; abs(amplitude) < 1 lattice | `body/jets.py` `Jet.__post_init__`, `jet_link_shapes`, `_surface_links` |
-| Jets with shifted storage | only in the all-blocked stepper with SRT and no LES | `body/jets.py` `_surface_links` |
-| SurfaceActuation | unshifted storage only | `body/objects.py` `SimObject.validate_surface_actuation` |
-| Raw boundary exchange (force) | blocked body levels only; the window ledger requires `observe_raw_exchange` | `lbm/refinement_stepper.py` `FixedPatchStepper.__init__` |
-| Checkpoint with Jets | refused | `simulation.py` `Simulation.save_checkpoint` |
-
-Raw exchange is the cut-link momentum reaction (wall + aperture), not a validated
-nozzle thrust or stress load. Jet amplitude is a lattice velocity, not a flow rate.
-
-Tests: `tests/unit/test_jets.py`, `test_jets_review.py`, `test_shifted_jets.py`, `test_raw_exchange.py`,
-`tests/validation/multigrid/test_refinement_jets.py`, `test_shifted_jets_gpu.py`, `test_raw_exchange_gpu.py`,
-`test_exchange_window.py`, `test_fine_surface_gpu.py`.
-
-## Observations from specific tested cases (not general bounds)
-
- SRT channel root vs uniform OneStep, strict-parity test
-  `tests/validation/multigrid/test_channel_root_gpu.py::ChannelRootGPU::test_uniform_matched_root`:
-  in one of its 18 sub-cases (2 storage modes x 3 profile/clamp/damp settings x 3 blocks; which
-  one is not recorded), 1 of the 4320 compared values differs, max abs 2.33e-10, max rel 1.77e-7
-  (about 2 ULP). The test remains failed; its cause and any general bound are unresolved.
- MRT root parity test
-  `tests/validation/multigrid/test_refinement_mrt_gpu.py::RefinementMRTGPU::test_uniform_matched_mrt_root`
-  (12 sub-cases: 2 storage modes x 2 profiles x 3 blocks, default outlet settings) passed bitwise
-  in the Horsea focused GPU run at K1 7813334 (2026-10-21).
- Periodic Taylor-Green Re 100, measured at 36ffc8b1 (V3 matched pair, N128 depth 2):
-  every per-sample screen passed; the constant explosion's aggregate worst velocity L2,
-  0.004418, exceeds its preregistered 0.002 budget, while projected_linear passed that budget.
- Curved-wall pressure (pilot harness, exact-q analytic annulus, tau 0.8): the coarse swirl r1
-  case exceeded its terminal density-gain cap (1.105e-4 vs 1e-4), so the frozen 9-case matrix
-  is NOT_ESTABLISHED. No validated fix exists. This is a pilot harness, not production code.
- DFG 2D-1 Re 20 (V4, SRT, t* 60, pressure-NEQ outlet and local Zou-He inlet): refined and uniform
-  runs were NOT_STEADY under the frozen steady rule, so no interval verdict was given.
-
-## Moving circles (dense `Simulation`, uniform grid only)
-
-Translating circles with optional spin are supported on the dense double
-buffer D2Q9 FP32 path only (not on `FixedPatchStepper` or refined levels).
-API, supported/rejected modes and limits: `docs/moving_bodies.md`; stage-1
-evidence: `docs/validation/moving_bodies_stage1.md`.
-
-## Not supported in this release
-
-3D, dynamic/automatic AMR (tagging, time-varying hierarchies beyond `remap_finest`),
-moving bodies on refined levels, pressure Jets, Jet checkpoints, LES or TRT on refined
-levels, partial (non-dividing) tiles.
@@ -33,7 +33,7 @@ origin is retained. Physical lower edges are `origin + spacing*(x,y)` on L0,
 `origin + spacing*(parent.fine_origin + (x,y)/4)` on L2.

 Factory options `coarse_boundary` and `objects` must declare `"periodic"` and
-an empty collection; L2 bodies use `objects` as described below.
+an empty collection; L2 bodies use `child_objects` as described below.
 LBMConfig's channel settings do not select this operator's boundary mode.
 Geometry metadata is factory-created;
 manual mutation/forging of metadata is unsupported. Caller certifies the
@@ -77,7 +77,7 @@ PYTHONPATH=src python -m unittest discover -s tests/unit -p 'test_synchronized_r

 ## Explicit runtime continuation

-`replacement = current.remap_finest(rectangles)` returns a new ready
+`replacement = current.remap_child(rectangles)` returns a new ready
 `FixedPatchStepper` at the **same absolute step_count**. It supports only
 periodic three-level runs with no L0/L1 bodies and an existing L2
 `FixedPatchSet2D`; stationary L2 bodies/Jets follow the support contract below.
@@ -99,7 +99,7 @@ resources; an actual old-device synchronization/read failure marks the old
 stepper failed, consistent with its existing failure semantics.

 ```python
-replacement = current.remap_finest([(20, 16, 36, 40)])
+replacement = current.remap_child([(20, 16, 36, 40)])
 # Explicitly choose the returned continuation only after success.
 current.close()
 current = replacement
@@ -119,7 +119,7 @@ Per-population conservation is not an advancement target under collision.

 ### Bounded pinned-body extension

-`replacement = current.remap_finest(rectangles, objects=original_objects)`
+`replacement = current.remap_child(rectangles, child_objects=original_objects)`
 also accepts stationary Circles inside the L2 union. Each body's **physical
 boundary, complete BFL support and current per-link velocity must remain
 identical**. Rectangles are not pinned: they may be split, merged or resized,
@@ -130,7 +130,7 @@ coverage and two-hop BFL transfer-footprint checks still apply. This is manual
 remapping, not adaptive body tracking or runtime body editing.

 Supply all original root edge-frame definitions in their construction order.
-Do not pass `current.boundaries[2].objects`: those are projected fine-local copies.
+Do not pass `current.child_boundary.objects`: those are projected fine-local copies.
 There is no retained mutable original-object registry. Before reading device
 state, remapping reprojects the supplied definition onto the old topology and
 compares exact ordered circle centers/radii, flags, physical cut links, body
@@ -1,49 +0,0 @@
-# DFG 2D-1 (Re 20) against the official reference intervals
-
-`tests/validation/run_dfg_re20.py` runs the steady DFG 2D-1 case on the refined
-channel root (D40 root, D80 wide fine patch) and on the uniform D80 grid. Geometry,
-inflow, initial state, layout and observation are those of the pinned Re100 runner
-(`run_refined_dfg.py`, `re100_helpers.py`, both unchanged); only the lattice
-viscosity is set for Re 20 (root tau 0.56, fine 0.62, uniform 0.62, lattice speed 0.01).
-
-Label: "compared against the official reference bands", not a full benchmark
-certification: the outlet is pressure-NEQ (`neq_extrap`), not do-nothing, and the
-inlet is local Zou-He.
-
-## Quantities
-
- Cd = 2 Fx / (rho U^2 D), Cl = 2 Fy / (rho U^2 D), interval means over each sample.
- p_diff = p(0.15, 0.2) - p(0.25, 0.2), linear extrapolation to the exact surface
-  points (`re100_helpers.pressure_probes`). The helper returns dp / (rho U^2) in
-  scaled units; p_diff = dp * 0.04 for U = 0.2 m/s, rho = 1. Both are reported.
- Official intervals (Schaefer & Turek 1996): Cd [5.57, 5.59], Cl [0.0104, 0.0110],
-  p_diff [0.1172, 0.1176].
-
-## Bounds and steady rule (frozen before any run)
-
- End time t* = 60 (30 s physical): 240,000 refined root steps, 480,000 uniform steps.
- One sample every t* = 0.5 (0.25 s) at the end of a synchronized root step; Cd and
-  Cl are interval means. Trailing window t* 50..60 inclusive (21 samples).
- Steady rule (our engineering choice, not official): in the window, for each of Cd,
-  Cl, p_diff, max - min <= 10 % and |least-squares slope x window| <= 2 % of its
-  official interval width (range 2e-3 / 6e-5 / 4e-5; slope 4e-4 / 1.2e-5 / 8e-6).
-  Absolute limits, so the small Cl is never a divisor. Never relaxed after a run.
- The verdict uses the window mean; the distance to the nearest interval edge is
-  reported for each quantity (negative outside).
- Force sign: fluid on cylinder, x along the inflow, y up from the bottom wall; Cd > 0
-  and the official Cl > 0 (`cd_positive` is reported).
- Not steady at t* = 60: status `NOT_STEADY`, no interval verdict. Health limits
-  (Mach <= 0.2, rho in [0.5, 1.5]) stop the run with `UNHEALTHY`.
- Steady: `WITHIN_INTERVALS` or `OUTSIDE_INTERVALS`, with the per-quantity verdict.
-
-## Run
-
-```
-python tests/validation/run_dfg_re20.py --output <new-dir> --plan
-CUDA_VISIBLE_DEVICES=<n> python tests/validation/run_dfg_re20.py --case both \
-    --collision SRT --output <new-dir> --max-wall-seconds <cap>
-```
-
-The uniform D80 control separates method error from refinement error. `--plan` writes `plan.json` only. A GPU run writes `plan.json` and `result.json`
-(per case: lattice parameters, every sample, window ranges, status, verdict).
-Host contract tests: `tests/unit/test_dfg_re20.py`.
@@ -1,242 +0,0 @@
-# Prescribed in-line oscillation: Dütsch Re 100 / KC 5 — PROTOCOL (review draft)
-
-Production under test: `claude/moving-bodies-s3a` at `653fd997` (unchanged).
-Primary source: Dütsch, Durst, Becker & Lienhart, J. Fluid Mech. 360, 249–271
-(1998), doi:10.1017/S002211209800860X. Source facts below were verified from
-the paper (Slack C0C78UFKGRM/1793335557.460509, TRON 1793356317–1793356724,
-page numbers given). Everything marked ENGINEERING is our a-priori choice,
-fixed before any benchmark result; it is not a paper uncertainty.
-
-## 0. Source facts (with provenance)
-
- Motion (p.251): `x_c = -A sin(2 pi f t)`; paper phase phi = 0 is the mean
-  position moving left at `-U_max`. KC = 5 gives `A/D = 5/(2 pi) = .7957747`.
- Start (p.254): the computation starts a quarter cycle before phi = 0, at
-  `x = +A` with zero velocity (phi = -90°).
- Experiment (pp.252, 254–256): D = 10 mm, L = .65 m, tank 1.2 × .7 × .7 m,
-  rho = 998.2 kg/m³, mu = 1.00818 mPa·s, Re = 100, KC = 5; LDA with 1° phase
-  bins and 200 samples per node and degree; no quantified experimental error
-  recovered.
- Profiles (Fig. 8, p.260): LAB-FIXED stations x1 = -6, 0, 6, 12 mm, i.e.
-  x/D = -.6, 0, .6, 1.2, at phi = 180°, 210°, 330°; u1 and u2 versus x2.
- Original numerics (§2): cylinder-fixed accelerated frame (`x_i = x~_i +
-  x_i,s`, outer velocity `-u_c`, inertial source `-rho du_c/dt`), O-grid outer
-  diameter 120 D, illustrated 192 circumferential nodes, 720 steps/cycle; tank
-  influence neglected.
- Force fit (verified): force ON THE BODY per unit span
-  `F1 = -0.5 rho D c_d xdot|xdot| - (pi/4) rho D² c_i xddot` with `x = -A sin phi`;
-  normalized by `0.5 rho D U_max²`: `c_d cos phi |cos phi| - (pi² c_i / KC) sin phi`.
-  `c_i` is the ADDED-MASS coefficient; total inertia `c_m = c_i + 1` is a
-  different convention and is not used.
- Table 1 computed Morison coefficients (c_d, c_i) for 96 / 192 / 384 perimeter
-  nodes at dt/T = 1/720: (2.15, 1.42), (2.10, 1.45), (2.09, 1.45). These are
-  fitted computed coefficients, not a measured force and not an error bar. The
-  paper states the coarse direct force is closer to the finest direct force
-  than the Morison fit, but gives no waveform-error norm.
-
-## 1. Kinematics, time levels and phase bookkeeping
-
- Our run is in the LAB frame: the circle moves, the fluid is initially at rest
-  (rho = 1, u = 0); no fictitious inertial source is added. Lab-fixed profile
-  stations are compared directly (no frame transform needed).
- Geometry reference: the circle's base centre is the INITIAL position, the
-  right turning point `x_mean + A`; the declared offset box is x in [-2A, 0],
-  y = 0. The body is never teleported: offset 0 at s = 0.
- Elapsed time s = n dt from the start. Analytic position relative to the mean
-  `x(s) = A cos(2 pi s / T)`, velocity `u(s) = -U_max sin(2 pi s / T)`; paper
-  phase `phi = (360 s / T - 90) mod 360`.
- Step n moves from s_n to s_{n+1}: target offset `x(s_{n+1}) - A`; wall
-  velocity = the single-step interval average `(x(s_{n+1}) - x(s_n)) / dt`
-  (analytic, supplied, not differenced from stored offsets). The per-step
-  force of `run(1)` / `read_force(normalize=True)` is attributed to that same
-  interval.
- Paper cycle k = 1, 2, ... spans `s in [T/4 + (k-1) T, T/4 + k T)`; the
-  initial quarter cycle (s < T/4) is cycle 0 and never scored. Every logged
-  sample carries (k, phi). Example: phi = 330° of cycle 1 is at s = 7T/6.
- T is chosen as a multiple of 360 native steps, so phi = 180°, 210°, 330° fall
-  exactly on step boundaries and 1° bins hold whole steps.
-
-## 2. Resolution ladder (uniform grid, fixed Mach), ENGINEERING
-
-| D (cells) | T (steps) | U_max = 5 D / T | nu_lat = U_max D / 100 | tau (3 nu + .5) |
-|---|---|---|---|---|
-| 20 | 2,520 | .039683 | .0079365 | .5238 |
-| 40 | 5,040 | .039683 | .015873 | .5476 |
-| 80 | 10,080 | .039683 | .031746 | .5952 |
-
- MRT collision. Mach fixed (Ma ≈ .0687); a separate Mach check at D = 40
-  with T = 10,080 (U_max halved, tau .5238) is labelled MACH and not part of the
-  ladder.
- Per-step displacement ≤ U_max ≈ .04 cells (bound .5).
-
-## 3. Domain and boundaries (finite-domain reproduction), ENGINEERING
-
-The paper's 120 D O-grid is not reproduced; our rectangular box is a
-reproduction choice. The native dense channel (zero-velocity inlet,
-pressure-NEQ outlet, bounce-back y walls) is a finite-domain approximation,
-not infinite still fluid. The G4 x-periodic / y-slip override is a separately
-labelled sensitivity family and never mixed into the primary ladder. The
-runner owner confirms the zero-velocity inlet is supported as configured
-before any run.
-
-Order (closed):
-1. Smoke + ledger at D = 40, native BC, 40 D × 40 D (finite box).
-2. Domain sensitivity before any literature statement: same BC, D = 40,
-   L ∈ {20 D, 40 D, 60 D}; record the change in Fx waveform, c_d, c_i and the
-   scored profiles.
-3. Optional labelled BC sensitivity: one x-periodic / y-slip case at D = 40,
-   40 D; reported as a delta against native only.
-4. Only after step 2 passes: the D = 20 / 40 / 80 ladder on the chosen BC and
-   domain.
-
-Domain criteria (a-priori, ENGINEERING; separate from the Table 1 bands): the
-reference is 60 D at D = 40; 20 D and 40 D are compared with it on the common
-window (same cycle indices) and the common valid point set:
- `RMS(Fx_L - Fx_60D) / F_ref ≤ .01` over the window (per-step waveforms);
- `|c_d,L - c_d,60D| ≤ .02` and `|c_i,L - c_i,60D| ≤ .02` (window fits);
- `max(|u_L - u_60D|, |v_L - v_60D|)` over common points `/ U_max ≤ .02`.
-The chosen domain is the smallest of {20 D, 40 D} passing all three; if
-neither passes, the domain verdict is FAIL and the ladder is not run.
- Memory/runtime: measured by a smoke run before each new size; measurements
-  inform scheduling only, never tolerances.
-
-## 4. Observables (raw, per step, preserved)
-
- `obs` Fx, Fy (CME) and all `MovingTables.DIAG` columns per step: CME,
-  CME + Wen and CME + cover − uncover reported separately; crossings, eq_only,
-  no_donor (no_donor must stay 0).
- Velocity u1, u2 on lab-fixed lines x/D = -.6, 0, .6, 1.2 (relative to the
-  mean cylinder position) versus x2, at the scored phases. Lab frame
-  throughout; if any body-frame intermediate is used, position and velocity
-  are both transformed.
- Sampling cost: raw force and diagnostics counters are read every step
-  (small). Flags and velocity fields are read only at the steps inside the
-  three prescribed 1° phase bins (φ ∈ [180, 181), [210, 211), [330, 331),
-  T/360 steps each) of the cycles needed for settling and scoring, plus
-  sparse declared audits; never every step.
- Point set: fixed x2/D sample points per station, identical on every grid
-  and declared before running; per point the interpolation weights are
-  recorded; the scored set is the common subset valid on all compared grids
-  at that phase, with its coverage recorded; point sets never change silently.
- Interpolation: bilinear on cell centres using only cells that are fluid at
-  that step (flags read back via `get_flags()`); weights renormalized over the
-  fluid corners; a sample with no fluid corner, or inside the circle at that
-  step, is MISSING and logged, never set to zero. One-degree bins keep valid
-  fluid weights. The numerical average need not mimic the 200 LDA samples.
-
-## 5. Periodic-regime gate (every case, before any statistic), ENGINEERING
-
-Ledger rows, same schema for every case: dx, dt (in D and T units); U_max, nu,
-Re, KC (lattice and nondimensional); T (native steps, nondimensional);
-duration (native steps, s/T, paper cycles); discard; accepted window; cycle
-ledger; verdict PASS or FAIL-CLOSED.
-
-Scales: `F_ref = 0.5 rho U_max² D`, `U_ref = U_max`; never a near-zero mean
-force as denominator.
-
- Settling metrics, cycle k−1 → k, phase-aligned by step within the cycle
-  (error budget: one fifth of the tightest comparison band of the same
-  observable, so residual drift cannot obscure a domain or resolution pass):
-  - waveform `RMS(dFx) / F_ref ≤ .002`;
-  - `|d mean|`, `|d RMS|`, `|d peak|` of Fx, each `/ F_ref ≤ .002`;
-  - scored profiles (fluid-only) `|du| / U_max`, `|dv| / U_max ≤ .004` at the
-    three phases × four stations;
-  - Morison `|dc_d| ≤ .004`, `|dc_i| ≤ .004`.
- Conservative comparison: every domain and cross-resolution criterion is
-  applied to `|difference| + drift_a + drift_b`, where drift is the largest
-  pair metric of that case inside the scored window.
- These constants (protocol.py SETTLE, DOMAIN, CROSS) are frozen before any
-  physical result; no post-result loosening.
- Rule: all metrics for N = 3 consecutive whole paper cycles → settled.
-
-Cycle indexing (worked example, binding). Paper cycle k spans
-`s/T in [0.25 + (k-1), 0.25 + k)`, i.e. φ0 → φ0; cycle 0 is the startup
-quarter `s/T < 0.25`. Pair p_k compares cycle k−1 with cycle k.
-
- Discarded: cycles 0, 1, 2 (s/T < 2.25). Pairs are formed only between
-  cycles ≥ 3, so the first pair is p_4 (3 → 4).
- Settling proof for a case: three consecutive pairs all pass; K_case = the
-  first cycle AFTER the last of those pairs. Earliest possible: pairs 3→4,
-  4→5, 5→6 pass ⇒ K_case = 7.
- Common window: K = max over compared cases of K_case; every case scores the
-  same three complete cycles K, K+1, K+2 and must stay settled continuously:
-  every pair p_j for j = its own K_case .. K+2 must pass (including the wait
-  between its local settle and the common K), otherwise that case is
-  FAIL-CLOSED.
- Cap: cycle k ends at s/T = k + 0.25, so the last admissible scored cycle is
-  11 (ends 11.25 T) and K ≤ 9. Examples: K = 7 → cycles 7–9 (ends 9.25 T);
-  K = 9 → cycles 9–11 (ends 11.25 T); any K_case > 9 → FAIL-CLOSED.
- Run length: cases run sequentially; each runs to the end of cycle 11
-  (11.25 T: 28,350 / 56,700 / 113,400 steps for D = 20 / 40 / 80; the 12 T
-  cap is 30,240 / 60,480 / 120,960) and keeps its scalar and profile data, then
-  the common K is chosen. An unscorable partial cycle 12 is not run.
- Profiles: an empty common valid point set is FAIL-CLOSED; coverage, missing
-  points, bin time weights (equal per step) and the original fluid corner
-  weight sums are reported.
- The earlier G4 timing check (100 coarse vs 400 diffusive-fine steps) was a
-  matched short transient, not periodic evidence.
-
-## 6. Metrics and per-observable criteria (ENGINEERING, not paper uncertainty)
-
-Three criteria stay separate; the G4 same-grid 2% target is not reused.
-
- Morison fit: least squares of the normalized per-step force over the
-  accepted window against the two basis functions, each averaged over its
-  single step interval, fixed paper phase, no free phase shift; c_d and
-  added-mass c_i per force candidate.
- Cross-resolution: every scored observable's error against its reference must
-  decrease monotonically D20 → D40 → D80 (necessary, not sufficient).
- Against Table 1 (computed fit, not measured force): at D ≥ 40,
-  `|c_d - 2.09| ≤ .15` and `|c_i - 1.45| ≤ .15`, and monotone.
- Force waveform against its own Morison reconstruction: residual reported
-  only, no pass/fail (the paper reports fit error above its coarse numerical
-  error and gives no percentage).
- Fig. 8 LDA profiles: QUALITATIVE ONLY. The original figure could not be
-  accessed or rendered; no digitized ordinates and no measurement uncertainty
-  exist. After a digitization with figure number, tool and uncertainty note:
-  `RMS(|du|, |dv|) / U_max ≤ .15` at D ≥ 40 and monotone; LDA error stays
-  UNQUANTIFIED and is stated with every comparison.
- Fy sanity (not literature): `|mean Fy| / F_ref ≤ .05` in the accepted window.
- No force candidate is selected for an RHS by these results; each is
-  reported.
-
-Superseded (earlier drafts): the velocity-jump start, guessed stations and
-phases, "C_M" for c_i, and the uncertainty wording; cycles 4–6, the 30-cycle
-cap and the earlier tolerance numbers.
-
-## 6b. Amendment: duration-only diagnostic (declared before the run)
-
- Background: the D40 domain stage (20 D / 40 D / 60 D, 11.25 T each) failed
-  settling in every box (no window). That result stands.
- One declared diagnostic: D = 40, 60 D box, from rest, through cycle 31
-  (157,500 steps = 31.25 T). Physics, settling tolerances, bands and
-  production unchanged; three proof pairs plus a continuously settled
-  K..K+2 with K ≤ 29.
- Invocation: `run.py --D 40 --box 60 --cycles 31` then
-  `analyze.py --horizon 31`; the JSON records `horizon` and `horizon_mode`.
-  Without `--horizon` the analyzer is the original cap-11 scoring.
- Failure at 31.25 T: report and stop; no automatic extension, matrix, D80
-  or VIV. A pass shows only that this box settles with time; it is not a
-  domain or literature pass.
- The phase-locked high-frequency force component (residual of the mean
-  waveform after its Morison reconstruction, above 20/T) is reported per case
-  as unqualified; it needs separate qualification before any Morison or
-  literature statement.
-
-## 6a. Driver unit tests (CPU, before any run)
-
- Phase/cycle arithmetic: s ↔ (k, φ), cycle boundaries, bin membership,
-  window/cap selection for K = 7, 8, 9, 10.
- Solid-aware interpolation: all-fluid, partial-solid (renormalized weights),
-  no-fluid (MISSING) and inside-circle cases.
- Interval-averaged Morison bases and the two-parameter fit on a synthetic
-  waveform with known c_d, c_i.
-
-## 7. Order and scope
-
-Protocol review → one-shot Dütsch driver (analytic `set_body` + `run(1)`,
-cycle ledger, lab-fixed fluid-only station sampler, two-basis Morison fit; no
-reusable runner until the first smoke shows shared helpers pay off; no
-production change) → smoke (memory/runtime) → domain sensitivity →
-ladder → physical-validation verdict → only then single-cylinder VIV. No AMR,
-no pinball, no manuscript work.
@@ -1,46 +0,0 @@
-# Moving circles — stage-1 evidence (development level)
-
-Owner criterion (Yanqi via TRON): prescribed motion and one free VIV case both
-"reasonably close" to a predeclared reference = development-stage success.
-This is practical closeness, not a formal validation claim. Every number
-below is from Astra's receipts as posted in Slack C0C78UFKGRM thread
-1793335557.460509; raw outputs stay on Horsea under `/tmp/celeris-results-*`
-and the Mac evidence directory (not in git).
-
-## Code
-
- Production: `src/` identical to `653fd997` (slices S1 `983020b6`,
-  S2a `b920a303`, S3a `653fd997`). CPU suites and GPU hold/crossing gates
-  passed on those slices (G0a/G0b population-bitwise; X1 crossing ledger).
- Research drivers: `research/duetsch_re100_kc5/` (`dd37883d`, capture
-  `a0aea3b9`) and `research/viv_re150/` (`fb507aa1`), run as committed.
-
-## Prescribed in-line oscillation (Dütsch et al. 1998, Re 100, KC 5)
-
- Protocol: `docs/validation/duetsch_re100_kc5_protocol.md`.
- Frozen settling gate (.002 F_ref waveform): **FAILED** and kept on record:
-  D40 domain stage (20/40/60 D, 11.25 T) and the 60 D duration diagnostic
-  (31.25 T, 0/28 pairs; last waveform drift .00613 F_ref).
- Unscored late-cycle CME fits c_d ≈ 2.02–2.05, c_i ≈ 1.46–1.48 vs the
-  paper's computed (2.09, 1.45); fields clean and symmetric (owner view).
-  The owner accepts ~0.61 % cycle drift at D40 for this stage; the gate is
-  not re-scored.
- Fig. 8 LDA profiles: qualitative only (no digitized ordinates).
-
-## Free transverse VIV (Kolahdouz §4.1.1 setup, Qin §4.5 target)
-
- Predeclaration: `docs/validation/viv_re150_predeclare.md` (agreed at
-  `1abfe954` under its former name `leontini_viv_predeclare.md`); run at `fb507aa1`, single case, D = 40, 75 D × 60 D.
- Result: status `scored`, 336,384 steps (t U/D = 336.4); A_max = .5464 D vs
-  .520 D (+5.1 %, inside the declared ±10 % band); mean half peak-to-peak
-  .5448 D; f/f_n = .955; block drifts .78/.29/.18 %, last-five spreads
-  .15/.11/.10 %; finite, no_donor = 0, no seed; 337.7 s, ~1.0 ms/step.
-
-## Limitations (binding)
-
- One resolution (D40) per case; no grid or time convergence.
- Structural RHS = CME + Wen is a theory-motivated stage choice; CME-only
-  and node-impulse variants were not run as RHS; no force law is validated.
- Boundary mismatches: NEQ outlet with backflow clamp vs traction outlet;
-  finite box; the strict Dütsch settling failure is unexplained.
- No mass correction at curved walls; ~1 ms/step host-coupled overhead.
@@ -56,62 +56,3 @@ Root must independently review and admit any execution. An admitted paired pilot
 the existing watchdog, device selection, `--gpu-gates-approved`, positive
 `--max-wall-seconds` and a new output directory, adding only `--exchange-window` to the
 selected collision's pilot command. No GPU or remote action was performed for this patch.
-
-## Public Jet diagnostic option
-
-`--collision MRT --exchange-window --jet-scenario zero|fixed|reverse` selects
-unshifted FP32, no LES, constant transfer on both existing public backends. Default
-`none` and the historical manifests remain unchanged. `zero` registers both Jets at
-zero amplitude and retains every existing DFG verdict, including pressure. `fixed`
-uses outward radial parabolic sectors at pi/2 and 3pi/2, half-width pi/12, peaks
-(+.001,-.001). Both use the existing D40/D80 geometry and U=.01. Sector origins are
-(80.5,81) in root edge coordinates and (160,160.5) in uniform node coordinates;
-radial extent is [0,1.005R]. `reverse` keeps those peaks through t*=300, updates both
-public setters at that completed boundary, and continues to 305 with opposite signs.
-
-Fixed diagnostic windows are 250–260, 260–270, 270–280, 280–290 and 290–300; reversal
-adds 300–305. Histories retain exact interval endpoints and root/uniform lattice
-impulses. The refined window uses total exchange; uniform uses public `read_force`
-batch averages. Driven windows report mean/min/max/RMS Cd/Cl without applying DFG
-reference or periodicity gates. Exit zero means healthy execution, not qualification;
-`matched_case_pass` remains false. No independent CV or stress-load claim is made.
-
-This opt-in records current source/helper hashes with the existing manifest format,
-checkout revision/dirty state and runner hash. Pilot/full must match that snapshot
-and the exact scenario. It does not relabel current source as historical evidence.
-Use the existing bounded plan/pilot/full commands with the three option flags above;
-full requires the matching completed t*=5 paired pilot. `step_seconds` includes force
-readback; observation/overhead and total wall time are separate, not kernel throughput.
-
-Add `--observe-cv` to record independent scalar control-volume samples from the
-already downloaded public macros. The pilot exercises this path at t*=.02..5;
-full records 501 endpoints at 290..300. Each `cv_history.jsonl` row contains actual
-root time, preceding interval start/duration/impulse, and two inventories/outward
-fluxes ordered [mass,Px,Py]. Exclude the first row's preceding impulse: that row
-supplies the initial inventory. Uniform native impulse converts by .5² to root
-units; refined ledger impulse is already in root units. Explicit native-aligned
-contours differ by .25 root cells in x and are recorded in the plan. Cropping
-retains the two-cell face-gradient stencils. No fields or per-link arrays are saved.
-`cv_observation_seconds` is the CV portion of observation/overhead time. Helper hash
-and the observation flag must match pilot/full. Time integration, temporal
-coarsening and any physical assessment remain separate offline work.
-
-## Bounded resolution and placement controls
-
-Defaults remain `--case both --uniform-diameter 80 --placement wide`. Single-case
-runs use `--case uniform` or `--case refined` and never report a matched-case pass.
-Their own reference/periodicity or driven-diagnostic results remain available.
-A single zero-Jet full run exits successfully only when its periodicity and the
-unchanged complete DFG reference verdict pass; driven completion is not qualification.
-
-The D160 option requires `--case uniform --uniform-diameter 160` and an explicit
-public Jet scenario. U and Jet speeds stay .01 and ±.001; viscosity is .016,
-grid 3521×658, center (320,320.5), radius80. CV uses root spacing/time factor .25,
-origin (.375,.75), impulse factor .0625, root viscosity .004, and x-face shift .125.
-
-`--case refined --placement compact` selects root bounds (48,48,128,128), fine
-168×168 and origin (46,46), with the same D40/fineD80 body/Jet resolution. Its CV
-contours are (52,52,112,112) and (50,50,120,120); complete face-gradient stencils
-are clear of both solids and the transfer footprint. Compact is refined-only.
-CV metadata gives each grid's spacing/origin/contours explicitly. Case, uniform
-diameter and placement must match the newly completed pilot in every receipt.
@@ -159,3 +159,303 @@ theoretical stress-consistency certification or production-kernel change.
 ## Repository integration

 The four Python harness files remain together under tests/validation/taylor_green, so runtime provenance hashes precisely this harness directory. Formatting changes produce a new harness identity; preparation and integrated receipts must not be mixed. All analytic definitions, numerical floors, assessment gates, sample times, and source-import assertions are unchanged. Production source is unchanged from the cd3 snapshot; these periodic tests do not waive the separate channel GPU gate.
+
+## Oblique shear wave (test-only diagnostic, not GPU-qualified)
+
+`shear_wave.py` reuses the frozen oracle's constants, cell centers and
+geometry. `oracle.py` is byte-identical, and `test_shear_wave.py` pins its
+eec4677 SHA-256. `run_case.py --flow shear_wave` selects the shear wave;
+the default flow and its receipt are the unchanged Taylor–Green path.
+
+### Convention
+
+Integer mode (2,1) on the L=N periodic root domain:
+- the wavevector `k = (2*pi/L)*(2,1)` points 26.565° from +x;
+- mode (1,2) would point 63.435°, and a wrong-mode test catches a swap.
+
+Polarization is `E = (-1,2)/sqrt(5)`, perpendicular to k:
+
+    u = U*E*sin(k.x + phi)*exp(-nu*|k|^2*t),  phi = 0,  p = const,  rho0 = 1
+
+`nu = U*N/100`, the Taylor–Green Re100 viscosity at the same N. This is an
+exact incompressible Navier–Stokes solution. The initial condition is FP64
+second-order equilibrium at the actual leaf centers, with no
+non-equilibrium part.
+
+### Physical caveats
+
+1. *Scope of the cubic-term argument.* The second-order D2Q9 equilibrium
+   lacks the cubic third moment `rho*u_a*u_b*u_g` of the Maxwellian (Dellar,
+   https://people.maths.ox.ac.uk/dellar/papers/Galilean.pdf, eq. 3). At
+   Navier–Stokes order this produces a stress error proportional to
+   `d_g(rho u_a u_b u_g)`.
+
+   For the ideal constant-density, zero-background transverse wave, k.E = 0
+   makes that contracted derivative vanish. That is the only claim made.
+   It does not remove other discrete or finite-Mach errors. It is not
+   guaranteed once AMR introduces density, longitudinal or higher-mode
+   contamination. The analytic NS field itself is exact.
+2. *Startup.* Equilibrium initialization is not the discrete shear
+   eigenmode (Mei et al., https://doi.org/10.1016/j.compfluid.2005.08.008).
+   - The decay rate is a free-intercept least-squares fit of ln R over the
+     samples with t* >= 0.12, where `R = hypot(a_hat, b_hat)`.
+   - The intercept cancels only a constant amplitude prefactor, and only
+     once a single exponential dominates.
+   - Per-interval rates and the maximum log-fit residual are kept, so a
+     lingering transient stays visible.
+   - Late sampling alone does not show that transients have gone.
+
+### Metrics
+
+Computed on ACTIVE leaf cells, each weighted by its area `4**-level` in
+root-cell units. The partition must cover the domain exactly once, and one
+global pressure gauge is used.
+
+- `a_hat`, `b_hat`: weighted least-squares fit of `u.E` onto sin/cos, using
+  the 2x2 Gram matrix of the actual composite quadrature. A wrong Fourier
+  mode need not project to exactly zero on this quadrature.
+- `amplitude_error = R/A_exact - 1`.
+- `phase_drift = atan2(b_hat, a_hat)`, in radians, reported separately.
+- Rates are positive (minus the fitted slope).
+  - Per root step they are compared with `nu*|k|^2`. Uniform 2N uses its
+    own `nu = 0.0768` at N=256 and doubled step counts.
+  - In t* they are compared with `5*(2*pi)^2/Re = 1.97392088`.
+  - `rate_error = |rate/exact - 1|`.
+- `velocity_l2`, `residual_l2` (velocity left after removing the fitted
+  mode) and `longitudinal_l2` (the `u.k_hat` part), all relative to the
+  exact-field norm. A longitudinal perturbation also raises the
+  full-vector residual and the velocity L2.
+- `spurious_pressure_rms`: the raw gauged rms of `p = (rho-1)/3`.
+- `spurious_pressure_scaled`: that rms divided by `A_exact(t)^2/4`, a
+  continuum reference scale. It is *not* the discrete, globally gauged
+  Taylor–Green norm on the composite grid. Exact pressure is constant, so
+  no relative-to-exact claim is made. Max and per-level values are kept.
+
+### Preregistered screens (`shear_wave.assess`)
+
+Run set: uniform N, uniform 2N, and refined depth-2 runs at root N.
+
+- `eps(N) = (|k| h_root)^2 = 5*(2*pi/N)^2`: dimensionless, coefficient
+  one, 0.01205 at N=128. This is a chosen screen, not a proven error bound.
+- Absolute screens:
+  - rate_error, max |phase_drift| (radians) and max residual_l2 must each
+    be <= eps;
+  - velocity_l2 <= 0.05, mass <= 1e-5, spurious_pressure_scaled <= 0.02.
+- Budgets keep the `assess.py` form, `refined <= max(2*control_N, floor)`:
+  - floors are 0.002 for rate and residual, 0.02 for pressure;
+  - the comparative pressure budget is always redundant:
+    `max(2*control, 0.02)` is never below the 0.02 absolute ceiling;
+  - raw ratios to both the root and finest controls, including raw
+    pressure rms, are always reported.
+- Every record is validated before any screen is applied:
+  - exact scheduled steps and t*, with no duplicates;
+  - every numeric field finite, including list fields and density;
+  - error quantities nonnegative and rho_min > 0;
+  - signed quantities (amplitudes, `amplitude_error`, `phase_drift`,
+    per-interval rate errors) keep their sign.
+- Outcomes are kept distinct:
+  - INVALID_CONTROL: a control or refined run is missing, a control is
+    incomplete or invalid, or the records come from mixed sources;
+  - INVALID_RUN: a refined record fails validation;
+  - CONTROL_SCREEN_FAIL: complete, valid controls fail their own screens.
+    Each refined run's `own_screens_pass` is still reported, but
+    `controlled_pass` is false, so it is never a controlled-comparison pass;
+  - PASS/FAIL: every refined run's `controlled_pass` (own screens and
+    budgets against valid, passing controls).
+  - Finite modal extinction (late R = 0) is a physical failure, not
+    malformed data. The run gets `rate_fit_valid=false` with null fit
+    quantities, and its other metrics are kept. Nothing is clipped and no
+    rate is invented. The result is CONTROL_SCREEN_FAIL for a control, or
+    FAIL for a refined run.
+  - Screens are never retuned.
+
+### Limitations
+
+One flow, one phase and one rectangle, SRT only. The rectangle's vertical
+faces span 0.625 tangential periods and its horizontal faces 1.5, so this
+is not placement robustness. Two resolutions show a trend, not an order.
+
+### Receipt assessment and runner integrity
+
+- Fixed four-case N128 contract:
+  `python assess_shear_wave.py U128.json U256.json R128_constant.json R128_projected.json --output report.json --expected-revision <sha>`.
+  It reuses the shared provenance, build, workload and sample-time checks
+  from `assess_projected_pairs.py`, and adds shear metadata checks (flow,
+  mode, polarization, angle, phase, eps, limits, disabled early trace, and
+  pinned `shear_wave.py` hash).
+  - Missing, extra, duplicate or mixed-source records give `INVALID_SET`,
+    as does any failed shared check.
+  - Otherwise the result comes from `shear_wave.assess`, which separates
+    `INVALID_CONTROL` from `CONTROL_SCREEN_FAIL`.
+- `run_case.verify_source(..., flow="shear_wave")` requires the imported
+  `shear_wave.py` to be the selected harness file with the pinned
+  `SHEAR_WAVE_SHA256`. The default TG flow does not import it.
+- Sample and READY finiteness use `finite_row`, which accepts scalar and
+  list diagnostics. For TG's all-scalar rows it behaves the same as before.
+- Merge note: native 92b8afe adds a `scaled_n256` receipt block. When the
+  two are merged, keep both blocks and make `--flow shear_wave` and
+  `scaled_n256` mutually exclusive. Not merged here.
+
+### Scaled shear diagnostic (opt-in `scaled_shear_n256`)
+
+Runner: `run_case.py --flow shear_wave --diagnostic scaled_shear_n256 --re 100`
+with one of these four cases:
+- `--n 256 --depth 1` (U256)
+- `--n 512 --depth 1` (U512)
+- `--n 256 --depth 2 --explosion constant` (constant R256)
+- `--n 256 --depth 2 --explosion projected_linear` (projected R256)
+
+Everything physical is unchanged from N128:
+- `rectangles(256,2)` covers the same physical box;
+- same t* schedule (16N root steps);
+- `nu = U*N/100`;
+- same `eps(N)`, limits and floors.
+
+`scaled_n256` (Taylor–Green, from native 92b8afe) and `scaled_shear_n256`
+each require their own flow, so they are mutually exclusive. N512 is
+accepted only through one of the two diagnostics. The shear diagnostic
+takes no early-pressure trace.
+
+Assessment:
+
+    python assess_shear_wave.py U256.json U512.json R256_constant.json R256_projected.json \
+        --diagnostic scaled_shear_n256 --reference-files <four de5b0cc N128 receipts> \
+        --output report.json --expected-revision <sha>
+
+- The scaled N256/512 case, build and workload checks come from the
+  92b8afe assessor. Its TG-only diagnostic identity and early-sampling
+  checks are not used. Instead every record must carry
+  `diagnostic=scaled_shear_n256`, and N128 records must carry none.
+- The reference N128 receipts are hash-pinned to the audited de5b0cc
+  evidence (commit cba6bca). They are never relabelled as fresh controls.
+- The report always includes, for each case:
+  - the raw signed rate bias `rate/exact - 1` and the interval errors;
+  - each refined run's signed excess over *each* uniform control (rate
+    bias, residual, raw pressure rms);
+  - the N128→N256 signed changes and ratios. The ratio is null when the
+    N128 value is zero.
+- These are descriptive. Passing or failing another floor-controlled
+  screen is not the conclusion, and a two-resolution ratio is not a
+  convergence order.
+- Portability: the receipt's recomputed `eps = |k|^2` is compared within
+  4 ULPs (`close_ulps`), not by exact equality. A cross-runtime replay
+  differed by one ULP: 0.012047856934923534 on Horsea vs
+  0.012047856934923532 elsewhere. Source and file hashes, case identity,
+  the other metadata and every scientific threshold stay exact.
+
+### Nested shear preset (opt-in `nested_shear_n128`)
+
+A fixed three-level, two-region preset, defined in `shear_nested.py`. The
+wave, phase, Re100/U=0.03, initialization, five sample times, eps(root N),
+limits and floors are the same as before.
+
+- Refinements, given as parent-frame `(x0, y0, x1, y1)` rectangles on
+  level-wide, zero-origin unions:
+  - L0→L1: `(16,16,60,112)`, `(68,24,112,120)`
+  - L1→L2: `(44,44,108,212)`, `(148,60,212,228)`
+- Leaves `[7936, 12288, 86016]`, hops `[2048, 4096, 8192]`, work
+  771227648 per refined case; 3723493376 for all four cases.
+- Level ν `[.0384, .0768, .1536]`, τ `[.6152, .7304, .9608]`.
+
+Cases (`run_case.py --flow shear_wave --diagnostic nested_shear_n128 --re 100`):
+- `--n 128 --depth 1`
+- `--n 512 --depth 1` — the finest control is 4N, not 2N
+- `--n 128 --depth 3`
+- `--n 128 --depth 3 --explosion projected_linear [--final-snapshot]`
+
+`--final-snapshot` is allowed only for the projected depth-3 case. It writes
+`<output>.final_macro.npz`, containing:
+- ACTIVE leaves packed as `level`/`i`/`j`;
+- `rho`, `ux`, `uy` from the FP64 physical populations at the final root
+  synchronization;
+- embedded metadata: exact time, phase, mode and config.
+
+It contains no populations, restart state or time series. Its SHA-256 and
+size go into the receipt. A file over 8 MiB is removed and reported, never
+kept. All old paths stay scalar-only.
+
+Assessment: `assess_shear_wave.py U128.json U512.json R128c.json R128p.json
+--diagnostic nested_shear_n128 --output report.json --expected-revision <sha>`.
+- It reuses the case-agnostic provenance checks from the TG assessor, plus
+  exact nested scales, builds, patch, workload, metadata and the pinned
+  `shear_nested.py` hash.
+- The physics is `shear_wave.assess` generalized only in its depth-3 / 4N
+  shape contract; the metrics are unchanged.
+- `shear_wave.py` is byte-identical (81d5c8ee…), so historical receipt
+  identities and verdicts are untouched.
+- This preset changes placement and refined volume as well as depth. It
+  gives no isolated cost of an extra level and no resolution trend.
+
+### Depth-2 twin of the nested preset (opt-in `twin_shear_n128`)
+
+`shear_twin.py` uses the same two L0→L1 boxes as `shear_nested.py`, with no
+L2. Leaves are `[7936, 33792]`, hops `[2048, 4096]`, and work is 154664960 per
+refined case (611319808 for all four).
+
+The campaign is four fresh runs:
+`run_case.py --flow shear_wave --diagnostic twin_shear_n128 --re 100` with
+- `--n 128 --depth 1`
+- `--n 256 --depth 1` (the finest control is 2N)
+- `--n 128 --depth 2`
+- `--n 128 --depth 2 --explosion projected_linear`
+
+There is no snapshot option. Older exact controls serve only as consistency
+checks; they are not reused as references.
+
+Assessment uses the same preset contract as the nested preset, through
+`assess_shear_wave.py ... --diagnostic twin_shear_n128`:
+- the physics is the unchanged depth-2 / 2N `shear_wave.assess`;
+- receipts must pin `shear_twin.py`, `shear_nested.py` and `shear_wave.py`;
+- `shear_nested.py` stays byte-identical (fa6cfe87…), so the 335624c nested
+  receipts still validate.
+
+Labels:
+- *Twin vs nested* is the effect of adding this nested L2 refinement.
+  Removing L2 also changes the finest spacing and refined volume, so it does
+  not isolate abstract depth.
+- *Twin vs the single-box depth-2 runs* is a placement/geometry contrast at
+  equal depth.
+- Neither contrast is additive by construction.
+- The thin-band/acoustic explanation for the nested L1 pressure is a
+  hypothesis, not established.
+
+### Signed interface-probe traces (opt-in `--probe-trace`, mechanism diagnostic)
+
+`shear_probes.py` (pinned) uses native's validated 24-target layout through
+box 1, in root-128 physical coordinates:
+- a horizontal line y = 56, crossing the vertical faces x = 16 and 22;
+- a vertical line x = 38, crossing the horizontal faces y = 16 and 22;
+- normal coordinates 12.5, 14.5, 15.5, 16.25, 17.25, 19.25, 20.75, 21.75,
+  22.125, 23.125, 24.125, 26.125.
+
+Each target maps to the nearest ACTIVE leaf center. The deterministic tie
+rule is: distance, then finer level, then smaller j, then smaller i. This
+gives 24 unique cells in every case, and nested has 3 L0 + 5 L1 + 4 L2 per
+transect. Maximum displacement from target to center is 0.625 root cells in
+U128 (0.177 in U512).
+
+Allowed cases:
+- nested U128, nested U512, nested projected depth 3;
+- twin projected depth 2.
+
+The option can't be combined with `--final-snapshot`.
+
+Sampling:
+- The receipt stores each probe's leaf level, `i`/`j`, actual cell center
+  and displacement from its target, all in root-physical units (N=128).
+- Grids differ between cases, so centers are *not* collocated. Analytic
+  fields are evaluated at each actual center (`shear_probes.residuals`), and
+  comparisons across cases are between residuals at nearby but distinct
+  centers.
+- Times are root-physical steps 0–128 and 1920–2048. U512 is sampled every 4
+  lattice steps to match.
+- Each sample stores `rho`, `ux`, `uy` from the FP64 physical populations,
+  POST-collision G at root synchronization only. No substep content is
+  observed, and grid-scale alternation can alias.
+
+What's kept and enforced:
+- The five qualification samples stay unchanged.
+- No field dumps. The trace is validated for exact schedule, finiteness and
+  a 600 kB cap. If invalid it is dropped and an error is recorded, keeping
+  the scalar receipt.
+- There are no new pass gates; this is a mechanism diagnostic only.
@@ -1,155 +0,0 @@
-# Single-cylinder free transverse VIV, Re 150 (Kolahdouz/Qin) — PREDECLARATION (agreed at 1abfe954)
-
-(File renamed from `leontini_viv_predeclare.md`; the Leontini Re 200 case is only the queued second case below.)
-
-Stage goal (Yanqi via TRON): prescribed Dütsch case + one VIV case both
-"reasonably close" to a predeclared reference = development-stage success, then
-cleanup. The frozen Dütsch settling failure (0/28 pairs at 31.25 T) stays on
-record. Practical closeness is not a formal validation claim. Agreed by
-Claude, Grok and Astra at 1abfe954; implemented in research/viv_re150/.
-
-## Primary case (one case)
-
- Reference: Qin et al., arXiv:2003.12186, §4.5 (maximum amplitudes at
-  U_red = 3…8: .075, .551, .520, .459, .370, .084 D in the text, as quoted by
-  Grok/Astra) for the target; setup from Kolahdouz et al., arXiv:2003.12046,
-  §4.1.1 (read 2026-10-30 via ar5iv): U* sweep 3–8 with amplitudes only in
-  Fig. 3(b) (no text values), domain [−30, 45] D × [−30, 30] D with the
-  cylinder "initially at rest and centered at the origin", uniform inflow on
-  the left, zero normal traction and tangential velocity at the outlet, zero
-  normal velocity and tangential traction on y = ±30 D; no initial
-  perturbation and no total simulated time stated.
- Re = 150, U* = U/(f_n D) = 5, m/(rho D²) = 2 (m* = rho_s/rho_f = 8/pi),
-  zeta = 0, f_n = sqrt(K/M)/(2 pi) in vacuum. Transverse DOF only.
- Target: A_max = .520 D (peak amplitude, Qin §4.5). Multi-code reference
-  (Kolahdouz ILE-NS, Qin II-LBM). Reference uncertainty: not stated; the
-  spread between codes is not quantified here.
-
-## Our reproduction (declared differences)
-
- D = 40, MRT, dense double buffer; U_lat = .04, nu = U D / 150 = .010667,
-  tau = .532.
- Nominal 75 D × 60 D lattice allocation (3000 × 2400), based on the
-  Kolahdouz §4.1.1 layout. Coordinate clarification of the existing run:
-  the driver uses `(30 D, (ny - 1)/2)` = `(1200, 1199.5)` in lattice
-  coordinates, or `(30 D, 29.9875 D)`. The earlier `(30 D, 30 D)` wording
-  described the nominal box, not the exact executed centre.
-  Free-slip reflection planes are at `y = .5` and `y = ny - 1.5 = 2398.5`;
-  their separation is 2398 cells = 59.95 D, with the centre exactly midway,
-  29.975 D from each wall. Node counts are not physical wall-to-wall lengths.
-  This corrects the description, without changing the historical geometry
-  or results. Qin's own box ([0, 40 D] × [0, 20 D], centre (10 D, 10 D)) is
-  the target paper's, not ours.
- Boundaries: uniform Zou–He inlet, NEQ outlet (rho = 1, backflow clamp),
-  free-slip y walls. Kolahdouz uses a traction outlet: declared mismatch.
- Qin's own VIV box (40 D × 20 D) is not used; a smaller box would be a
-  declared cost cut with more blockage, not "the same case".
- Allowed y offset ±1.5 D; peak transverse speed ≈ .026 cells/step (bound .5).
-
-## Structure, coupling and time levels
-
- M = 2 rho D² (lattice rho = 1), f_n = U/(5 D) = 2e-4 per step, K = M (2 pi f_n)²,
-  zeta = 0. Equation of motion uses the structural mass only.
- Per-step sequence (binding): known (y_n, v_n) and the last completed force
-  F_last → candidate (y_{n+1}, v_{n+1}) by the update below → `set_body` with
-  offset y_{n+1} and wall velocity (y_{n+1} − y_n)/dt with lattice dt = 1 (interval average; a
-  different quantity from the endpoint v_{n+1}) → `run(1)` → only on success:
-  commit y_n ← y_{n+1}, v_n ← v_{n+1}, F_last ← force read for that step (failure
-  semantics: see the window section). Whether the
-  measured force represents the interval's start, midpoint or end is not
-  asserted; the one-step lag is declared, not corrected.
- Initial state: fluid initialized by `Simulation.initialize()` to the uniform
-  inlet velocity U everywhere (the code's actual initial condition; the
-  source gives no fluid initial condition), body at rest at the declared
-  centre, y_0 = v_0 = 0, F_last = 0.
- Structural update over one step with constant force F = F_last (exact
-  harmonic solution, zeta = 0): y_e = F/K, w = 2 pi f_n,
-  y^{n+1} = y_e + (y^n − y_e) cos w + (v^n / w) sin w,
-  v^{n+1} = −(y^n − y_e) w sin w + v^n cos w.
- Primary RHS (single coupled run): CME + Wen (theory-motivated stage choice:
-  Galilean-invariant link correction; G4 could not separate it from CME).
-  Raw CME and the node terms are logged as diagnostics of that trajectory;
-  the node impulse is not added. A run with CME-only as RHS is a separate,
-  labelled sensitivity case, decided separately. Neither RHS is claimed proven.
-
-## Window, failure semantics, acceptance (engineering, development stage)
-
-Clocks: lattice dt = 1; T_n = 1/f_n = 5,000 steps. Response cycles are
-counted from the measured signal; T_n is used only for the seed check.
-
- Start: body at rest at the declared centre (the only initial condition the
-  source states), y_0 = v_0 = 0, F_last = 0; fluid uniform at U (as
-  initialized by the code; our choice, not the source's).
- Seed (conditional, one time, declared): at step n_seed = 200,000
-  (t = 40 T_n), if max |y_t| over states t in [175,000, 200,000) is below
-  .01 D, then
-  in that step, after the check and before the candidate update, set
-  v_n += 2 pi f_n (.01 D) (F_last unchanged) and proceed normally; the
-  geometry moves continuously through the update. `seed_applied`, step and
-  size are logged; never repeated or changed.
- Cycle boundary (discrete, fixed threshold): step n closes a cycle iff
-  y[n−1] < 0 and y[n] ≥ 0 (upward crossing of the equilibrium y = 0);
-  y_0 = 0 is not a crossing; no boundary fewer than 2 samples after the
-  previous one.
- Per cycle: positive peak max(y), negative peak min(y), mean offset
-  (time-mean of y), amplitude a = (max − min)/2 (the only amplitude used for
-  settling).
- Eligibility: a completed cycle is counted (toward the settling proof and
-  the 150 budget) only if a ≥ .01 D; ineligible cycles are logged, never
-  counted, so near-zero motion cannot settle or pass.
- Seed reset: if the seed is applied, the incomplete cycle at n_seed is
-  discarded and the settling proof starts empty; the 150 budget and the
-  native cap keep running from t = 0.
- Windows: adjacent non-overlapping blocks of 10 counted cycles;
-  W_k = mean amplitude of block k (W_k ≥ .01 D by eligibility, so no zero
-  denominator).
- Block rule R(k), k ≥ 2: |W_k − W_{k−1}| / W_{k−1} ≤ .02 and, for the last 5
-  cycles of block k, max_i |a_i − ā_5| / ā_5 ≤ .01 with ā_5 their mean.
- Settled at the end of block k when R(k) holds. Scoring = the next two
-  blocks k+1, k+2 (20 counted cycles); both must satisfy R. If one fails,
-  that block becomes the new reference: the settling proof restarts from it
-  and continues within the caps (deterministic; no other retry). A pass
-  requires one complete stable 20-cycle scoring window before a cap; success
-  stops after its 20th cycle.
- Caps (both always armed; the first hit wins and is reported): 150 counted
-  response cycles including the 20 scoring cycles (so settling must complete
-  by counted cycle 130) → `timeout_response_cycles`; 1,000,000 native steps
-  (200 T_n) → `timeout_native_steps`.
- Durations reported: total steps, t U/D, counted and uncounted cycles,
-  measured T_resp (mean boundary interval); N_resp / f_n only as a labelled
-  secondary clock.
- Growth is not a failure: initial VIV growth is physical. Checked every
-  step (FAIL-CLOSED): non-finite y, v or force; |y| > 1.0 D (the tighter
-  gate; about twice the largest reference peak, .551 D) or the ±1.5 D offset
-  box reached; no_donor > 0; a failed upload/step/sync.
- On any failure the driver stops and reports; it never retries,
-  sub-iterates, retunes the RHS or parameters, or starts a second case.
-  Device-side failures (upload/step/sync, no_donor) mark the Simulation
-  failed through the existing lifecycle; input rejection by `set_body`
-  (offset box, speed, step bound) and timeouts end the driver run without
-  that mark.
- Target metric over the 20 scoring cycles: A_max/D = max over those cycles
-  of max(|positive peak|, |negative peak|) about y = 0 (Qin reports "maximum
-  amplitude"); also reported: mean amplitude, positive and negative peaks,
-  mean offset, f/f_n (no target).
- Acceptance: |A_max − .520 D| ≤ .052 D (±10 %), stated together with the
-  boundary mismatch and the absence of a quoted reference uncertainty. A pass
-  is "reasonably close" for the stage: not grid convergence, not force-RHS
-  validation, and it does not touch the Dütsch settling record.
- Driver reads force and the small diagnostics per step only; field reads
-  only at a few predeclared snapshots. No runtime claim: there is no measured
-  timing on this grid yet (the D40/60D receipt is a different, sampled case).
-
-## Plumbing smoke (not the benchmark)
-
-`run.py --smoke --D 20 --steps 32` runs exactly 32 steps of the same BC
-package and coupling loop (no seed, settle or score; never scored);
-status `smoke_ok` iff every step is finite, no_donor stays 0 and the body
-stays inside its box. The physical case is only the default invocation
-(`--D 40`, no `--smoke`).
-
-## Queued, not in this stage
-
-Leontini et al. JFS 22 (2006) Re = 200, m* = 10, zeta = 0.01, U* = 5.0 (needs
-the owners' c_crit convention and a Fig. 1 digitization). D80, literature
-claims, pinball, AMR, BC redesign, threshold changes.
@@ -1,9 +1,9 @@
 """Public API demo: fixed 2:1 patch with a stationary, optionally actuated circle.

 From this checkout, after checking the selected physical GPU is idle:
-    PYTHONPATH="$PWD/src" CUDA_VISIBLE_DEVICES=0 python examples/fixed_patch_circle.py
-    ... --speed -0.002 --mode slot_reservoir
-Both levels use blocked storage (--base-block, --fine-block tiles).
+    PYTHONPATH="$PWD/src" CUDA_VISIBLE_DEVICES=0 python examples/fixed_patch_circle.py --fine-block 16 20
+    ... --speed -0.002 --fine-block 16 20 --mode slot_reservoir
+Omit --fine-block for the (equivalent) dense fine storage.

 A short smoke run (default 128 coarse steps): it shows setup, stepping and
 fluid-only diagnostics, not a developed flow, accuracy or long-time stability.
@@ -40,13 +40,13 @@ def config(mode):
 def leaf_masks(run, mode):
    """Known fluid leaves: uncovered coarse cells (minus wall rows in slot mode)
    and fine ACTIVE cells outside the body."""
-    p = run.hierarchy.pairs[0]
+    p = run.patch
    x0, y0, x1, y1 = p.bounds
    coarse = np.ones(p.coarse_shape, bool)
    coarse[y0:y1, x0:x1] = False
    if mode == "slot_reservoir":
        coarse[[0, -1]] = False
-    solid = (run.boundaries[1].flags.reshape(p.fine_shape) & SOLID) != 0
+    solid = (run.fine_boundary.flags.reshape(p.fine_shape) & SOLID) != 0
    return coarse, (p.fine_kind == ACTIVE) & ~solid


@@ -71,10 +71,8 @@ def main():
    parser.add_argument("--mode", choices=("periodic", "slot_reservoir"), default="periodic")
    parser.add_argument("--speed", type=float, default=.002,
                        help="normal surface velocity, coarse lattice units (+ blows, - sucks, 0 passive)")
-    parser.add_argument("--base-block", type=int, nargs=2, metavar=("BY", "BX"), default=(12, 8),
-                        help="root tile; must divide the 24 x 32 root")
-    parser.add_argument("--fine-block", type=int, nargs=2, metavar=("BY", "BX"), default=(16, 20),
-                        help="fine tile; must divide the whole fine allocation (32 x 40 here)")
+    parser.add_argument("--fine-block", type=int, nargs=2, metavar=("BY", "BX"),
+                        help="blocked fine storage; must divide the whole fine allocation (32 x 40 here)")
    parser.add_argument("--steps", type=int, default=128)
    args = parser.parse_args()
    if args.steps < 0:
@@ -88,20 +86,20 @@ def main():
    body = SimObject(0, geometry=CircleGeometry(*CENTER, RADIUS), center=CENTER, radius=RADIUS,
                     surface_actuation=spec)
    cfg = config(args.mode)
+    fine_block = tuple(args.fine_block) if args.fine_block else None
    # The caller owns the CUDA context; the stepper must be closed first (the
    # nested with-statement does that).
    with CudaContext(0) as context, FixedPatchStepper(
-            cfg, context=context, coarse_boundary=args.mode, refinements=[BOUNDS],
-            level_blocks=[tuple(args.base_block), tuple(args.fine_block)],
-            level_objects=[(), (body,)]) as run:
-        p = run.hierarchy.pairs[0]
+            cfg, BOUNDS, context=context, coarse_boundary=args.mode,
+            fine_objects=[body], fine_block=fine_block) as run:
+        p = run.patch
        # Rest equilibrium is already postcollision G, so no initial collision is
        # needed. Non-leaf entries (covered, ghost, solid) are discarded by initialize.
        rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]
        run.initialize(np.broadcast_to(rest, (9, *p.coarse_shape)),
                       np.broadcast_to(rest, (9, *p.fine_shape)))
-        storage = f"blocked root {tuple(args.base_block)} fine {tuple(args.fine_block)}"
-        print(f"mode={args.mode} storage={storage} speed={args.speed:+g} "
+        storage = f"blocked {fine_block}" if fine_block else "dense"
+        print(f"mode={args.mode} fine storage={storage} speed={args.speed:+g} "
              f"(fine allocation {p.fine_shape[0]}x{p.fine_shape[1]}, fine origin {p.fine_origin})")
        masks = leaf_masks(run, args.mode)
        start = leaf_diagnostics(*run.download(), masks)
@@ -31,7 +31,6 @@ from CelerisLab.lbm.refinement import ACTIVE
 from CelerisLab.lbm.refinement_stepper import FixedPatchStepper

 BOUNDS, AMPLITUDE, WIDTH = (16, 4, 32, 28), .02, 12
-LEVEL_BLOCKS = [(12, 8), (8, 8)]  # blocked storage: 48x48 root, 56x40 fine window
 TIMES, MAX_MACH, MAX_SECONDS = (0, 300, 1200), .1, 120


@@ -133,8 +132,7 @@ def main():
                  lattice_model='D2Q9', collision='SRT', streaming='double_buffer',
                  store_precision='FP32', ddf_shifting=False, les_enabled=False)
    report = dict(config=dict(nx=48, ny=48, bounds=BOUNDS, W=WIDTH, A=AMPLITUDE, nu=.1,
-                              rho=1, tau_coarse=.8, tau_fine=1.1, coarse_boundary='slot_reservoir',
-                              level_blocks=LEVEL_BLOCKS),
+                              rho=1, tau_coarse=.8, tau_fine=1.1, coarse_boundary='slot_reservoir'),
                  guards=dict(check_every=50, positive_density=True, finite=True,
                              max_Mach=MAX_MACH, max_seconds=MAX_SECONDS,
                              timing='cooperative checks, not an exact interruption deadline'),
@@ -150,10 +148,9 @@ def main():
                  samples=[], status='running', last_synchronized_coarse_step=0)
    start, run = time.monotonic(), None
    try:
-        with CudaContext(0) as context, FixedPatchStepper(cfg, context=context,
-                coarse_boundary='slot_reservoir', refinements=[BOUNDS],
-                level_blocks=LEVEL_BLOCKS) as run:
-            p = run.hierarchy.pairs[0]
+        with CudaContext(0) as context, FixedPatchStepper(cfg, BOUNDS, context=context,
+                coarse_boundary='slot_reservoir') as run:
+            p = run.patch
            masks = [np.ones(p.coarse_shape, bool), p.fine_kind == ACTIVE]
            masks[0][[0, -1]] = False
            masks[0][4:28, 16:32] = False
@@ -16,7 +16,7 @@ from CelerisLab.config import load_lbm_config
 from CelerisLab.cuda.context import CudaContext
 from CelerisLab.lbm.equilibrium import compute_feq_d2q9, compute_macro_from_ddf
 from CelerisLab.lbm.refinement import ACTIVE
-from CelerisLab.lbm.refinement_stepper import FixedPatchStepper
+from CelerisLab.lbm.refinement_stepper import PeriodicPatchStepper


 def shear_equilibrium(shape, origin, dx, period):
@@ -48,9 +48,8 @@ def main():
                  nx=16, ny=16, viscosity=.1, velocity=1e-3, rho=1.0,
                  lattice_model="D2Q9", collision="SRT", streaming="double_buffer",
                  store_precision="FP32", ddf_shifting=False, les_enabled=False)
-    with CudaContext(0) as context, FixedPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)],
-                                                           level_blocks=[(16, 16), (24, 24)]) as run:
-        p = run.hierarchy.pairs[0]
+    with CudaContext(0) as context, PeriodicPatchStepper(cfg, (4, 4, 12, 12), context=context) as run:
+        p = run.patch
        coarse = shear_equilibrium(p.coarse_shape, (0, 0), 1.0, cfg.ny)
        fine = shear_equilibrium(p.fine_shape, p.fine_origin, .5, cfg.ny)
        coarse_leaf = np.ones(p.coarse_shape, dtype=bool)
@@ -1,220 +0,0 @@
-"""Sparse scientific frames and the approved new-reproduce presentation idiom.
-
-Frame gears/UI colors/rotation sectors derive from DynamisLab continuous_video.py
-(read-only SHA in docs). Modern velocity decoding and moving coordinates are used.
-All camera limits, vorticity limits, and motion scale are fixed, never following y.
-"""
-from functools import lru_cache
-import json
-from pathlib import Path
-import subprocess
-import time
-
-import numpy as np
-
-D,U,CY=40.,.005,510.5
-SIZE=(1280,800)
-CW,CCW='#8854B8','#138F78'
-MAIN=(0,120,1280,440)
-INSET=(960,492,1240,772)
-MAIN_LIMITS=(6.4,57.6,-6.4,6.4)
-INSET_LIMITS=(28.75,33.75,-2.5,2.5)
-
-
-def frame_schedule(steps,base_interval,accelerated=False):
-    """Original 15-frame gear holds; only readback cadence changes."""
-    if accelerated:
-        ramp=15*(1+2+5)*base_interval
-        if steps<=2*ramp:
-            raise ValueError('too short for both display ramps')
-        blocks=[(s,15*s*base_interval) for s in (1,2,5)]
-        blocks += [(10,steps-2*ramp)]
-        blocks += [(s,15*s*base_interval) for s in (5,2,1)]
-    else:
-        blocks=[(1,steps)]
-    result,done=[],0
-    for speed,duration in blocks:
-        end=done+duration
-        while done<end:
-            done=min(done+speed*base_interval,end)
-            result.append((done,speed))
-    return result
-
-
-def video_schedule(phase_steps,smoke=False):
-    if smoke:
-        phase=frame_schedule(phase_steps,8)
-    else:
-        # First 80 D/U of each phase is fast display; last 80 is normal.
-        half=phase_steps//2
-        phase=frame_schedule(half,800,True)
-        phase += [(half+n,s) for n,s in frame_schedule(phase_steps-half,800)]
-    return {p*phase_steps+n:s for p in range(3) for n,s in phase}
-
-
-def vorticity(ux,uy,flags):
-    """Centered dx=1 curl; mask every stencil touching nonfluid, no filling."""
-    ux,uy=np.asarray(ux,dtype=float),np.asarray(uy,dtype=float)
-    fluid=(flags&1)!=0
-    valid=(fluid[1:-1,1:-1]&fluid[1:-1,:-2]&fluid[1:-1,2:]&
-           fluid[:-2,1:-1]&fluid[2:,1:-1])
-    curl=((uy[1:-1,2:]-uy[1:-1,:-2])-(ux[2:,1:-1]-ux[:-2,1:-1]))/2
-    result=np.full(ux.shape,np.nan)
-    result[1:-1,1:-1]=np.where(valid,curl*D/U,np.nan)
-    return result
-
-
-def pixel(x,y,box,limits):
-    left,top,right,bottom=box
-    x0,x1,y0,y1=limits
-    return left+(x-x0)/(x1-x0)*(right-left),bottom-(y-y0)/(y1-y0)*(bottom-top)
-
-
-@lru_cache(maxsize=12)
-def font(size,bold=False):
-    from PIL import ImageFont
-    name='DejaVuSans-Bold.ttf' if bold else 'DejaVuSans.ttf'
-    return ImageFont.truetype('/usr/share/fonts/truetype/dejavu/'+name,size)
-
-
-def draw_circle(draw,x,y,r,wall_speed,box,limits):
-    cx,cy=pixel(x,y,box,limits)
-    radius=r*(box[2]-box[0])/(limits[1]-limits[0])
-    rect=(cx-radius,cy-radius,cx+radius,cy+radius)
-    draw.ellipse(rect,fill='white',outline='#263D4B',width=2)
-    if wall_speed is None:
-        return
-    fraction=abs(wall_speed)/(12*U)
-    if not np.isfinite(fraction) or fraction>1.00001:
-        raise RuntimeError('applied rotation exceeds fixed display reference')
-    r2=radius*.72
-    inner=(cx-r2,cy-r2,cx+r2,cy+r2)
-    draw.ellipse(inner,fill='#E4E9ED')
-    angle=min(fraction,1)*360
-    start,end=(-90,-90+angle) if wall_speed<0 else (-90-angle,-90)
-    if angle>0:
-        draw.pieslice(inner,start,end,fill=CW if wall_speed<0 else CCW)
-
-
-class Video:
-    def __init__(self,out,scene,bodies,phase_steps,smoke=False,source='unknown'):
-        from PIL import Image
-        from matplotlib import colormaps
-        self.out,self.scene,self.bodies=out,scene,bodies
-        self.schedule=video_schedule(phase_steps,smoke)
-        self.phase_steps=phase_steps
-        self.source=source
-        self.records=[]
-        self.palette=np.rint(colormaps['RdBu_r'](np.linspace(0,1,21))[:,:3]*255).astype('uint8')
-        self.log=open(out/'ffmpeg.log','wb')
-        self.proc=subprocess.Popen(['ffmpeg','-hide_banner','-loglevel','warning','-n',
-            '-f','rawvideo','-pix_fmt','rgb24','-s','1280x800','-r','30','-i','pipe:0',
-            '-an','-c:v','libx264','-threads','4','-preset','fast','-crf','18',
-            '-pix_fmt','yuv420p','-movflags','+faststart',str(out/'continuous_viv.mp4')],
-            stdin=subprocess.PIPE,stderr=self.log)
-        self.closed=False
-        self.seconds=0.
-
-    def capture(self,sim,step,phase,eff,rows):
-        speed=self.schedule.get(step)
-        if speed is None:
-            return
-        from PIL import Image,ImageDraw
-        start=time.monotonic()
-        macro=sim.get_macroscopic()
-        flags=sim.get_flags().reshape(sim.field.ny,sim.field.nx)
-        fluid=(flags&1)!=0
-        if any(not np.isfinite(macro[k][fluid]).all() for k in ('rho','ux','uy')):
-            raise RuntimeError('nonfinite fluid field at video sample')
-        omega=vorticity(macro['ux'],macro['uy'],flags)
-        finite=np.isfinite(omega)
-        index=np.floor((np.clip(np.nan_to_num(omega),-3,3)+3)/6*21).astype(int).clip(0,20)
-        rgb=self.palette[index]
-        rgb[~finite]=[232,235,237]
-        field=Image.fromarray(rgb[::-1])
-        canvas=Image.new('RGB',SIZE,'white')
-        draw=ImageDraw.Draw(canvas)
-        for box,limits in ((MAIN,MAIN_LIMITS),(INSET,INSET_LIMITS)):
-            x0,x1,y0,y1=limits
-            # Lattice cell-centre coordinates -> image pixel-edge coordinates.
-            crop=(x0*D+.5,sim.field.ny-(CY+y1*D+.5),
-                  x1*D+.5,sim.field.ny-(CY+y0*D+.5))
-            picture=field.crop(crop).resize((box[2]-box[0],box[3]-box[1]),Image.Resampling.BOX)
-            canvas.paste(picture,box[:2])
-            if box==INSET:
-                _,eq=pixel(30,0,box,limits)
-                for x in range(box[0],box[2],10):
-                    draw.line((x,eq,min(x+5,box[2]),eq),fill='#657887',width=1)
-            if self.scene=='karman':
-                draw_circle(draw,10,0,1,None,box,limits) if box==MAIN else None
-            for bid,w in zip(self.bodies,eff):
-                obj=sim.bodies.objects[bid]
-                x,y=obj.motion.centre(obj.motion.applied)
-                draw_circle(draw,x/D,(y-CY)/D,obj.radius/D,float(w),box,limits)
-        x0,y0=pixel(INSET_LIMITS[0],INSET_LIMITS[2],MAIN,MAIN_LIMITS)
-        x1,y1=pixel(INSET_LIMITS[1],INSET_LIMITS[3],MAIN,MAIN_LIMITS)
-        draw.rectangle((x0,y1,x1,y0),outline='#647C8C',width=1)
-        draw.rectangle(INSET,outline='#647C8C',width=1)
-        def text(x,y,value,size=16,color='#263D4B',bold=False):
-            draw.text((x,y),value,font=font(size,bold),fill=color)
-        on=phase=='on'
-        text(28,15,'INCOMING FLOW',12,'#667887',True)
-        text(28,39,'Steady inflow' if self.scene=='steady' else 'Periodic cylinder wake',29,bold=True)
-        text(28,83,'One continuous flow and oscillator trajectory | Re_D = 50 | zero structural damping',15)
-        text(850,18,'CYLINDER ROTATION',12,bold=True)
-        text(850,43,'Clockwise',14,CW);text(1020,43,'Counterclockwise',14,CCW)
-        text(850,70,'Sector angle = actual surface speed',13,'#667887')
-        text(850,90,'Full circle = 12 x reference inflow speed',13,'#667887')
-        draw.line((24,453,1256,453),fill='#E5EBEF')
-        text(28,465,'CLOAKING CONTROL',12,'#667887',True)
-        draw.rounded_rectangle((28,490,92,524),radius=17,fill='#137F73' if on else '#A8B4BC')
-        cx=75 if on else 45
-        draw.ellipse((cx-12,495,cx+12,519),fill='white')
-        text(108,491,'ON' if on else 'OFF',22,'#137F73' if on else '#667887',True)
-        text(195,493,('Fixed rotations' if self.scene=='steady' else 'Frozen PPO') if on else 'Zero rotation',18)
-        text(570,467,f't U/D = {step*U/D:.2f}',18,bold=True)
-        local=(step-1)%self.phase_steps+1
-        transition=(phase!='off_before' and local*U/D<=1.)
-        text(570,495,f'Playback {speed}x | '+('switch transient' if transition else phase.replace('_',' ')),16)
-        text(960,467,f'Fixed lab-frame inset | y/D={rows[-1,1]/D:+.3f}',13,bold=True)
-        # Motion trace: fixed +/-D limits, a fixed 60 D/U trailing time span.
-        box=(55,560,895,732)
-        draw.rectangle(box,outline='#CCD6DD')
-        middle=(box[1]+box[3])/2
-        draw.line((box[0],middle,box[2],middle),fill='#A8B4BC')
-        t=step*U/D
-        left=max(0.,t-60)
-        first=max(0,int(left*D/U))
-        sample=rows[first::max(1,(len(rows)-first)//1200)]
-        xy=[(box[0]+(r[0]*U/D-left)/60*(box[2]-box[0]),middle-r[1]/D*(box[3]-box[1])/2) for r in sample]
-        if len(xy)>1:draw.line(xy,fill='#263D4B',width=2)
-        text(28,535,'Transverse displacement y/D (fixed scale; dashed inset line = equilibrium)',14)
-        text(24,554,'+1',12);text(25,642,'0',12);text(24,722,'-1',12)
-        text(55,739,f'{left:.1f}',12);text(835,739,f'{left+60:.1f}',12)
-        text(350,739,'response time t U/D',12)
-        text(28,774,f'Vorticity D/U: fixed [-3, +3] | exploratory, not convergence proof | source {self.source[:8]}',12)
-        self.proc.stdin.write(canvas.tobytes())
-        local=step%self.phase_steps
-        if not self.records or local in (0,self.phase_steps//2) or self.records[-1]['phase']!=phase:
-            canvas.save(self.out/f'keyframe-{step:09d}.png')
-        elapsed=time.monotonic()-start
-        self.seconds+=elapsed
-        self.records.append(dict(frame=len(self.records),step=step,absolute_clock=sim.stepper.step_count,
-            tU_D=t,phase=phase,playback_speed=speed,y_D=float(rows[-1,1]/D),
-            surface_speeds=eff.tolist(),render_s=elapsed,
-            fraction_finite_outside_color_limits=float(np.mean(np.abs(omega[finite])>3))))
-
-    def close(self):
-        if self.closed:return
-        self.closed=True
-        self.proc.stdin.close()
-        code=self.proc.wait(timeout=60)
-        self.log.close()
-        receipt=dict(frames=self.records,frame_count=len(self.records),fps=30,size=SIZE,
-            duration_s=len(self.records)/30,render_total_s=self.seconds,ffmpeg_exit=code,
-            normalization='centered dx=1 vorticity D/U, all 5 stencil cells fluid',
-            color_limits=[-3,3],color_bins=21,main_limits_D=MAIN_LIMITS,inset_limits_D=INSET_LIMITS,
-            y_origin_lattice=CY,trace_limits_D=[-1,1],inset_camera='fixed lab frame',
-            acceleration='frame cadence only; native solver and SI unchanged')
-        (self.out/'video.json').write_text(json.dumps(receipt,indent=2)+'\n')
-        if code:raise RuntimeError(f'ffmpeg exit {code}')
@@ -1,222 +0,0 @@
-"""Continuous OFF -> ON -> OFF VIV illustration; docs/continuous_viv_video.md.
-
-Each invocation owns ONE Simulation and ONE oscillator. Rendering never advances
-the solver or changes the policy clock. No topology changes or moving restart.
-"""
-from __future__ import annotations
-
-import argparse
-import json
-from pathlib import Path
-import subprocess
-import sys
-import time
-
-import numpy as np
-
-ROOT = Path(__file__).resolve().parents[2]
-sys.path.insert(0, str(ROOT))
-from research.karman_viv import run as base
-from research.continuous_viv.render import Video, frame_schedule
-
-D, U, SCALE, SI = 40., .005, 2., 3200
-PHASES = ('off_before', 'on', 'off_after')
-STEADY_WALL = np.array([0., -5.1, 5.1]) * U
-
-
-def timing(scene, smoke):
-    if smoke:
-        return 1,32,32
-    # Prior video's steady interval was 1000 at D20; diffusive D40 uses 4000.
-    return (320,4000,2048000) if scene=='steady' else (400,SI,2048000)
-
-
-def command(scene, phase, obs, model):
-    """Physical surface speeds; OFF is not a zero normalized PPO action."""
-    if phase != 'on':
-        return np.zeros(3), np.array([0., .5, -.5])
-    if scene == 'steady':
-        return STEADY_WALL.copy(), np.full(3, np.nan)
-    action = np.asarray(model.predict(obs, deterministic=True)[0], np.float32)
-    if action.shape != (3,) or not np.isfinite(action).all() or (np.abs(action)>1).any():
-        raise RuntimeError('invalid PPO action')
-    return base.wall_target(action, SCALE), action
-
-
-def add_scene(sim, scene):
-    if scene == 'karman':
-        return base.add_scene(sim, SCALE, moving=True)
-    from CelerisLab.body.motion import Translation
-    probes = [sim.add_body('sensor', c, 10.) for c in base.scaled_points(base.PROBES, SCALE)]
-    envelope = Translation((0., 0., -D, D), .025, shared=True)
-    bodies = [sim.add_body('circle', c, D/2, translation=envelope)
-              for c in base.scaled_points(base.CENTRES, SCALE)]
-    return probes, bodies
-
-
-def evolve(sim, probes, bodies, structure, force, *, scene, model, norm,
-           intervals, si, out, render, start, wall_cap):
-    """One native-step loop across all phases; completed SI feeds the next SI."""
-    from CelerisLab.body.motion import MovingTables
-    cols = {k:i for i,k in enumerate(MovingTables.DIAG)}
-    count = len(PHASES)*intervals*si
-    rows = np.lib.format.open_memmap(out/'steps.npy', mode='w+', dtype=np.float64,
-                                   shape=(count, len(base.STEP_COLUMNS)))
-    # The completed count is authoritative after any interrupted run.
-    completed = 0
-    obs = np.zeros(12, np.float32)
-    signals, switches = [], []
-    origin_clock = sim.stepper.step_count
-    status = 'running'
-    try:
-        for phase in PHASES:
-            switches.append(dict(phase=phase, step=completed, absolute_clock=sim.stepper.step_count,
-                                 y=structure.y, v=structure.v, previous_rhs=force,
-                                 input_observation=obs.tolist()))
-            for i in range(intervals):
-                target, action = command(scene, phase, obs, model)
-                # Match the frozen inference contract: reset the EMA every SI.
-                eff = np.zeros(3)
-                sensor_sum, force_sum = np.zeros(6), np.zeros(6)
-                for k in range(si):
-                    if k % 1000 == 0:
-                        base.check_time(start, wall_cap)
-                    y1, v1 = structure.candidate(force)
-                    if not np.isfinite([y1,v1]).all() or abs(y1)>D:
-                        raise RuntimeError('nonfinite structure or |y| > D; no retuning')
-                    eff = base.ema(eff, target, SCALE)
-                    omega = eff/(D/2)
-                    for bid,w in zip(bodies,omega):
-                        sim.set_body(bid, omega=float(w), offset=(0.,y1), vy=y1-structure.y)
-                    sim.run(1, zero_obs=True, sync_obs=True)
-                    d = sim.moving_diagnostics()
-                    cme,wen = d[:,cols['cme_y']], d[:,cols['wen_y']]
-                    node = d[:,cols['cover_jy']]-d[:,cols['uncover_jy']]
-                    row = (completed+1,y1,v1,*cme,*wen,*node,
-                           d[:,cols['eq_only']].sum(),d[:,cols['no_donor']].sum(),
-                           d[:,cols['crossings']].sum(),*omega)
-                    if not np.isfinite(row).all() or row[13] != 0:
-                        raise RuntimeError('nonfinite moving diagnostic or no_donor')
-                    f=np.array([v for p in bodies for v in sim.read_force(p)[:2]])
-                    s=np.array([v for p in probes for v in sim.read_sensor(p)[:2]])
-                    if not np.isfinite([f,s]).all():
-                        raise RuntimeError('nonfinite force/sensor observation')
-                    sensor_sum += s
-                    force_sum += f
-                    force=float(cme.sum(dtype=np.float64)+wen.sum(dtype=np.float64))
-                    rows[completed]=row
-                    completed += 1
-                    structure.y,structure.v=y1,v1
-                    if sim.stepper.step_count != origin_clock+completed:
-                        raise RuntimeError('noncontinuous solver clock')
-                    render(sim, completed, phase, eff, rows[:completed])
-                if scene == 'karman':
-                    raw, obs, clipped = base.observation(sensor_sum/si,force_sum/si,SCALE,norm)
-                else:
-                    # Steady uses prescribed rotations, not a model or borrowed norm.
-                    raw=np.r_[sensor_sum/si,force_sum/si]
-                    clipped=0
-                signals.append(dict(phase=phase, step=completed, raw=raw.tolist(),
-                                    observation=obs.tolist(), clipped=clipped,
-                                    action=action.tolist() if np.isfinite(action).all() else None,
-                                    target_surface_speed=target.tolist()))
-                if (i+1)%10==0 or i+1==intervals:
-                    rows.flush()
-                    progress=dict(phase=phase, interval=i+1, completed_steps=completed,
-                                  tU_D=completed*U/D, y_D=structure.y/D,
-                                  elapsed_s=time.monotonic()-start)
-                    (out/'progress.json').write_text(json.dumps(progress)+'\n')
-                    print(json.dumps(progress),flush=True)
-        status='duration_completed_not_physics_qualified'
-    except BaseException as exc:
-        status=f'error: {type(exc).__name__}: {exc}'
-        raise
-    finally:
-        rows.flush()
-        (out/'signals.json').write_text(json.dumps(signals,allow_nan=False)+'\n')
-        report=dict(status=status,completed_steps=completed,origin_clock=origin_clock,
-                    final_clock=sim.stepper.step_count,switches=switches,
-                    elapsed_s=time.monotonic()-start,columns=base.STEP_COLUMNS,
-                    M=structure.mass,K=structure.stiffness,fn=structure.frequency,damping=0.,
-                    max_abs_y_D=float(np.abs(rows[:completed,1]).max()/D) if completed else None)
-        (out/'report.json').write_text(json.dumps(report,indent=2,allow_nan=False)+'\n')
-
-
-def main():
-    ap=argparse.ArgumentParser(description=__doc__)
-    ap.add_argument('--scene',choices=('steady','karman'),required=True)
-    ap.add_argument('--out',type=Path,required=True)
-    ap.add_argument('--model',type=Path)
-    ap.add_argument('--norm',type=Path)
-    ap.add_argument('--release-dir',type=Path)
-    ap.add_argument('--smoke',action='store_true',help='3 x 32 steps, all switches, no physical result')
-    ap.add_argument('--wall-seconds',type=float,default=10800.)
-    args=ap.parse_args()
-    if not np.isfinite(args.wall_seconds) or args.wall_seconds<=0:
-        ap.error('finite positive wall cap required')
-    if args.scene=='karman':
-        if args.model is None or args.norm is None:
-            ap.error('Karman requires the frozen model and norm')
-        if base.sha(args.model)!=base.MODEL_SHA or base.sha(args.norm)!=base.NORM_SHA:
-            ap.error('frozen Karman model/normalizer hash mismatch')
-        if not args.smoke and args.release_dir is None:
-            ap.error('physical Karman requires its verified static release')
-    elif any(p is not None for p in (args.model,args.norm,args.release_dir)):
-        ap.error('steady uses constant control and its own warmup, no borrowed policy or release')
-    out=args.out.resolve()
-    if out==ROOT or ROOT in out.parents:
-        ap.error('output must be outside checkout')
-    out.mkdir(parents=True,exist_ok=False)
-    intervals,si,warm=timing(args.scene,args.smoke)
-    cfgpath=out/'config.json'
-    cfgpath.write_text(json.dumps(base.config(40),indent=2)+'\n')
-    source=subprocess.check_output(['git','-C',str(ROOT),'rev-parse','HEAD'],text=True).strip()
-    case=dict(source=source,scene=args.scene,smoke=args.smoke,D=D,U=U,nu=.004,
-              phases=PHASES,SI=si,intervals_per_phase=intervals,
-              phase_duration_tU_D=intervals*si*U/D, mass_ratio=4.,fn_D_U=.2,zeta=0.,
-              first_ppo_observation='previous complete OFF interval; no reset at switches',
-              rhs='previous native step CME_y+Wen_y; no filtering; policy uses SI-mean CME',
-              control='fixed (0,-5.1,+5.1)U' if args.scene=='steady' else 'frozen karman_re100 PPO; actual Re_D50',
-              model_sha256=base.sha(args.model) if args.model else None,
-              norm_sha256=base.sha(args.norm) if args.norm else None,
-              config_sha256=base.sha(cfgpath),render='sparse post-step snapshots only; no step skipping')
-    model=base.load_policy(args.model) if args.model else None
-    norm=json.loads(args.norm.read_text()) if args.norm else None
-    seed=None
-    if args.scene=='karman' and not args.smoke:
-        seed,force=base.saved_release(args.release_dir)
-        case['release_sha256']=base.sha(args.release_dir/'release.npz')
-    (out/'case.json').write_text(json.dumps(case,indent=2)+'\n')
-    from CelerisLab import Simulation
-    from CelerisLab.body.motion import MovingTables
-    started=time.monotonic()
-    structure=base.Structure(4.,2.5e-5,0.,D)
-    video=None
-    try:
-        with Simulation(str(cfgpath)) as sim:
-            probes,bodies=add_scene(sim,args.scene)
-            sim.initialize()
-            if seed is not None:
-                case['release_transfer']=base.install_seed(sim,seed)
-                del seed
-            else:
-                base.warmup(sim,warm-1,started,args.wall_seconds)
-                sim.run(1)
-                d=sim.moving_diagnostics()
-                force=float(d[:,MovingTables.DIAG.index('cme_y')].sum(dtype=np.float64)
-                            +d[:,MovingTables.DIAG.index('wen_y')].sum(dtype=np.float64))
-            case.update(warmup_executed=0 if 'release_transfer' in case else warm,
-                        origin_clock=sim.stepper.step_count)
-            (out/'case.json').write_text(json.dumps(case,indent=2)+'\n')
-            phase_steps=intervals*si
-            video=Video(out,args.scene,bodies,phase_steps,smoke=args.smoke,source=source)
-            evolve(sim,probes,bodies,structure,force,scene=args.scene,model=model,norm=norm,
-                   intervals=intervals,si=si,out=out,render=video.capture,
-                   start=started,wall_cap=args.wall_seconds)
-    finally:
-        if video is not None:
-            video.close()
-
-
-if __name__=='__main__':
-    main()
@@ -1,224 +0,0 @@
-"""Ledger, settling, common window and Morison fits for Dütsch cases (numpy only).
-
-    python analyze.py CASE_DIR [CASE_DIR ...]   # cases of one comparison
-"""
-from __future__ import annotations
-
-import json
-import math
-import os
-import sys
-
-import numpy as np
-
-import protocol as p
-
-
-def load(path):
-    with open(os.path.join(path, "case.json")) as fh:
-        case = json.load(fh)
-    raw = np.load(os.path.join(path, "raw.npz"))
-    case.update(force=raw["force"], diag=raw["diag"], samples=raw["samples"], path=path)
-    return case
-
-
-def cycle_slices(case):
-    """{k: slice of step indices m whose interval [m, m+1] lies in paper cycle k}."""
-    T, q = case["T"], case["T"] // 4
-    return {k: slice(q + (k - 1) * T, q + k * T)
-            for k in range(1, case["cycles"] + 1) if q + k * T <= len(case["force"])}
-
-
-def coarse_wave(case, k, r=1):
-    """Normalized per-step Fx of cycle k, averaged over r native steps per sample."""
-    f = case["force"][cycle_slices(case)[k], 0] / case["F_ref"]
-    return f.reshape(-1, r).mean(axis=1)
-
-
-def profiles(case, k):
-    """{(phase, station, x2): (u, v)} of cycle k, time-averaged over the bin steps
-    (equal weights per step) from valid samples only."""
-    s = case["samples"]
-    acc = {}
-    for _, _, ph, xs, x2, u, v, _ in s[s[:, 1] == k]:
-        if not (math.isnan(u) or math.isnan(v)):
-            acc.setdefault((ph, xs, x2), []).append((u, v))
-    return {key: tuple(np.mean(vals, axis=0)) for key, vals in acc.items()}
-
-
-def coverage(case, k):
-    s = case["samples"]
-    rows = s[s[:, 1] == k]
-    missing = int(np.isnan(rows[:, 5]).sum())
-    return dict(samples=len(rows), missing=missing, bin_steps=len(set(rows[:, 0])),
-                min_fluid_weight=float(np.nanmin(np.where(rows[:, 7] > 0, rows[:, 7], np.nan)))
-                if len(rows) else math.nan)
-
-
-def common_points(dicts):
-    keys = set(dicts[0])
-    for d in dicts[1:]:
-        keys &= set(d)
-    return sorted(keys)
-
-
-def candidates(case):
-    """Per-step Fx of each reported force candidate (none is selected as an RHS)."""
-    d = case["diag"]
-    return {"cme": d[:, 0], "cme_wen": d[:, 0] + d[:, 2], "cme_node": d[:, 0] + d[:, 6] - d[:, 9]}
-
-
-def cycle_morison(case, ks, fx=None):
-    T = case["T"]
-    fx = case["force"][:, 0] if fx is None else fx
-    idx = np.concatenate([np.arange(len(fx))[cycle_slices(case)[k]] for k in ks])
-    b = np.array([p.interval_bases(int(m), T) for m in idx])
-    return p.morison_fit(fx[idx] / case["F_ref"], b[:, 0], b[:, 1])
-
-
-def pair_metrics(case, k):
-    a, b = coarse_wave(case, k - 1), coarse_wave(case, k)
-    pa, pb = profiles(case, k - 1), profiles(case, k)
-    common = common_points([pa, pb])  # empty set -> inf -> pair fails (FAIL-CLOSED)
-    prof = max((max(abs(pa[c][0] - pb[c][0]), abs(pa[c][1] - pb[c][1])) for c in common),
-               default=math.inf) / case["u_max"]
-    (cd0, ci0), (cd1, ci1) = cycle_morison(case, [k - 1]), cycle_morison(case, [k])
-    m = dict(wave=float(np.sqrt(np.mean((b - a) ** 2))),
-             scalar=float(max(abs(b.mean() - a.mean()), abs(np.sqrt(np.mean(b * b)) - np.sqrt(np.mean(a * a))),
-                              abs(np.abs(b).max() - np.abs(a).max()))),
-             profile=float(prof), morison=float(max(abs(cd1 - cd0), abs(ci1 - ci0))),
-             profile_points=len(common))
-    m["pass"] = all(m[key] <= tol for key, tol in p.SETTLE.items())
-    return m
-
-
-def hf_component(case, ks):
-    """Unqualified phase-locked high-frequency force component (reported, not checked):
-    mean CME waveform over cycles ks minus its two-basis Morison reconstruction,
-    split at 20/T; cycle differencing does not remove it."""
-    T = case["T"]
-    if not ks:
-        return dict(label="unqualified phase-locked HF force component, not checked", cycles=[])
-    mean = np.mean([coarse_wave(case, k) for k in ks], axis=0)
-    c_d, c_i = cycle_morison(case, ks)
-    q = T // 4
-    b = np.array([p.interval_bases(q + m, T) for m in range(T)])
-    resid = mean - (c_d * b[:, 0] - (np.pi ** 2 * c_i / p.KC) * b[:, 1])
-    spec = np.fft.rfft(resid)
-    high = spec.copy()
-    high[:21] = 0.0
-    energy = one_sided_energy(spec, T)
-    return dict(label="unqualified phase-locked HF force component, not checked",
-                cycles=list(ks), hf_rms_over_F_ref=float(np.sqrt(np.mean(np.fft.irfft(high, T) ** 2))),
-                hf_energy_fraction=float(energy[21:].sum() / max(energy.sum(), 1e-300)),
-                top_harmonics=[int(j) for j in np.argsort(energy[21:])[::-1][:5] + 21])
-
-
-def one_sided_energy(spec, n):
-    """Parseval-consistent energy per rfft bin: interior bins count twice, DC and
-    (for even n) Nyquist once."""
-    w = np.full(len(spec), 2.0)
-    w[0] = 1.0
-    if n % 2 == 0:
-        w[-1] = 1.0
-    return w * np.abs(spec) ** 2
-
-
-def ledger(case, horizon=p.LAST_SCORED):
-    ks = [k for k in sorted(cycle_slices(case)) if k <= horizon]
-    pairs = {k: pair_metrics(case, k) for k in ks if k - 1 > p.DISCARD}
-    return pairs, p.settled_start({k: v["pass"] for k, v in pairs.items()})
-
-
-def main(argv):
-    """argv: CASE_DIR ... [--reference CASE_DIR]; the reference defaults to the
-    largest D (resolution ladder); domain runs name the 60 D case explicitly."""
-    ref_path = None
-    if "--reference" in argv:
-        i = argv.index("--reference")
-        ref_path, argv = argv[i + 1], argv[:i] + argv[i + 2:]
-    horizon, explicit = p.LAST_SCORED, "--horizon" in argv  # default: original scoring
-    if explicit:
-        i = argv.index("--horizon")
-        horizon, argv = int(argv[i + 1]), argv[:i] + argv[i + 2:]
-    paths = argv if ref_path is None or ref_path in argv else argv + [ref_path]
-    cases = [load(path) for path in paths]
-    for c in cases if explicit else ():  # complete cycles 1..N; never pad or shift
-        if c["cycles"] < horizon or len(c["force"]) < round((0.25 + horizon) * c["T"]):
-            raise SystemExit(f"{c['path']}: run does not contain complete cycles 1..{horizon}")
-    ledgers = [ledger(c, horizon) for c in cases]
-    window = p.common_window([k for _, k in ledgers],
-                             [{k: v["pass"] for k, v in pairs.items()} for pairs, _ in ledgers],
-                             last_scored=horizon)
-    report = dict(window=window, horizon=horizon, cases=[],
-                  horizon_mode="default-cap" if horizon == p.LAST_SCORED else
-                  "extended duration diagnostic (declared amendment, D40/60D only)")
-    for case, (pairs, k_case) in zip(cases, ledgers):
-        limit = round((0.25 + horizon) * case["T"])  # events inside the horizon only
-        entry = {key: case[key] for key in ("path", "D", "T", "box", "n", "u_max", "nu", "tau", "A",
-                                            "steps", "cycles", "F_ref")}
-        entry.update(duration_T=case["steps"] / case["T"], K_case=k_case, pairs=pairs,
-                     coverage={k: coverage(case, k) for k in sorted(cycle_slices(case))
-                               if p.DISCARD < k <= horizon},
-                     no_donor=float(case["diag"][:limit, 13].sum()),
-                     eq_only=float(case["diag"][:limit, 12].sum()),
-                     hf_component=hf_component(case, window or tuple(
-                         [k for k in sorted(cycle_slices(case)) if p.DISCARD < k <= horizon][-3:])))
-        if window:  # residual drift inside the scored window (pairs K..K+2)
-            entry["window_drift"] = {key: max(pairs[k][key] for k in window)
-                                     for key in ("wave", "profile", "morison")}
-            entry["morison_obs"] = cycle_morison(case, window)
-            entry["morison"] = {name: cycle_morison(case, window, fx)
-                                for name, fx in candidates(case).items()}
-            entry["fy_mean"] = float(np.mean(np.concatenate(
-                [case["force"][cycle_slices(case)[k], 1] for k in window])) / case["F_ref"])
-        report["cases"].append(entry)
-    if window and len(cases) > 1:  # cross-resolution waveform against the finest case
-        fine = (next(c for c in cases if c["path"] == ref_path) if ref_path
-                else max(cases, key=lambda c: c["D"]))
-        report["reference"] = fine["path"]
-        ref = np.concatenate([coarse_wave(fine, k) for k in window])
-        for case, entry in zip(cases, report["cases"]):
-            r = fine["T"] // case["T"]  # 1 for equal-D domain runs
-            ref_c = ref.reshape(-1, r).mean(axis=1)
-            own = np.concatenate([coarse_wave(case, k) for k in window])
-            entry["wave_rms_vs_finest"] = float(np.sqrt(np.mean((own - ref_c) ** 2)))
-        for k in window:  # profiles on the common valid point set of all compared cases
-            per_case = [profiles(c, k) for c in cases]
-            keys = common_points(per_case)
-            report.setdefault("common_profile_points", {})[k] = len(keys)
-            if not keys:
-                report["verdict"] = "FAIL-CLOSED: empty common profile set"
-                continue
-            fine_p = per_case[cases.index(fine)]
-            for case, entry, prof in zip(cases, report["cases"], per_case):
-                d = max(max(abs(prof[key][0] - fine_p[key][0]), abs(prof[key][1] - fine_p[key][1]))
-                        for key in keys) / case["u_max"]
-                entry.setdefault("profile_max_vs_finest", {})[k] = float(d)
-        ref_entry = report["cases"][cases.index(fine)]
-        for entry in report["cases"]:  # conservative: difference + both drifts
-            if entry is ref_entry:
-                continue
-            drift = {key: entry["window_drift"][key] + ref_entry["window_drift"][key]
-                     for key in ("wave", "profile", "morison")}
-            dm = max(abs(entry["morison"]["cme"][0] - ref_entry["morison"]["cme"][0]),
-                     abs(entry["morison"]["cme"][1] - ref_entry["morison"]["cme"][1]))
-            entry["conservative"] = dict(
-                wave=entry["wave_rms_vs_finest"] + drift["wave"],
-                profile=max(entry.get("profile_max_vs_finest", {}).values(), default=math.inf)
-                + drift["profile"],
-                morison_cme=dm + drift["morison"])
-            bands = p.DOMAIN if ref_path else p.CROSS  # domain runs name the 60 D reference
-            c = entry["conservative"]
-            entry["pass_scope"] = (
-                ("wave+profile+morison_cme" if "morison" in bands else "wave+profile")
-                + ": conservative (|diff| + both window drifts) on the obs/CME Fx waveform and "
-                "simulation-to-simulation profiles; CME+Wen and CME+node reported, not checked; "
-                "no Fig. 8 / literature verdict")
-            entry["pass"] = (c["wave"] <= bands["wave"] and c["profile"] <= bands["profile"]
-                             and ("morison" not in bands or c["morison_cme"] <= bands["morison"]))
-    print(json.dumps(report, indent=1, default=float))
-
-
-if __name__ == "__main__":
-    main(sys.argv[1:])
@@ -1,52 +0,0 @@
-"""Research-only field capture helpers for the Dütsch driver (numpy only).
-
-Snapshots are taken at the first step of the scored phase bins in declared
-cycles: a near-body crop at full resolution and a fluid-weighted block-mean
-downsample of the whole domain; plus scalar trends at every bin read.
-"""
-from __future__ import annotations
-
-import numpy as np
-
-CROP_X, CROP_Y, DOWN = 8.0, 6.0, 8      # crop half-widths in D; downsample factor
-STRIP = 2.0                             # inlet/outlet strip width in D
-
-
-def crop_box(xm, ym, D, n, body_extent):
-    """Inclusive integer crop (x0, x1, y0, y1); fail closed if it leaves the domain
-    interior or does not contain the body's swept extent (x_lo, x_hi, y_lo, y_hi)."""
-    x0, x1 = int(round(xm - CROP_X * D)), int(round(xm + CROP_X * D))
-    y0, y1 = int(round(ym - CROP_Y * D)), int(round(ym + CROP_Y * D))
-    if x0 < 1 or y0 < 1 or x1 > n - 2 or y1 > n - 2:
-        raise ValueError("capture crop leaves the domain interior")
-    bx0, bx1, by0, by1 = body_extent
-    if not (x0 <= bx0 and bx1 <= x1 and y0 <= by0 and by1 <= y1):
-        raise ValueError("capture crop clips the body's swept extent")
-    return x0, x1, y0, y1
-
-
-def downsample(field, fluid, f=DOWN):
-    """Fluid-weighted f x f block means; NaN where a block has no fluid cell."""
-    ny, nx = field.shape
-    h, w = ny // f, nx // f
-    v = np.where(fluid, field, 0.0)[:h * f, :w * f].reshape(h, f, w, f).sum(axis=(1, 3))
-    c = fluid[:h * f, :w * f].reshape(h, f, w, f).sum(axis=(1, 3))
-    with np.errstate(invalid="ignore", divide="ignore"):
-        return np.where(c > 0, v / np.maximum(c, 1), np.nan).astype(np.float32)
-
-
-def fluid_mean(field, fluid, xs=slice(None), ys=slice(None)):
-    m = fluid[ys, xs]
-    return float(field[ys, xs][m].mean()) if m.any() else float("nan")
-
-
-def trend_row(s, k, ph, rho, ux, uy, fluid, D, n, crop):
-    """(s, cycle, phase, <rho>, <ux>, <uy>, <rho>_crop, inlet <rho>, <ux>, outlet <rho>, <ux>)."""
-    w = max(1, int(round(STRIP * D)))
-    x0, x1, y0, y1 = crop
-    cx, cy = slice(x0, x1 + 1), slice(y0, y1 + 1)
-    inlet, outlet, inner = slice(1, 1 + w), slice(n - 1 - w, n - 1), slice(1, n - 1)
-    return (s, k, ph, fluid_mean(rho, fluid), fluid_mean(ux, fluid), fluid_mean(uy, fluid),
-            fluid_mean(rho, fluid, cx, cy),
-            fluid_mean(rho, fluid, inlet, inner), fluid_mean(ux, fluid, inlet, inner),
-            fluid_mean(rho, fluid, outlet, inner), fluid_mean(ux, fluid, outlet, inner))
@@ -1,136 +0,0 @@
-"""Pure arithmetic of the Dütsch Re 100 / KC 5 protocol (numpy only, no CUDA).
-
-docs/validation/duetsch_re100_kc5_protocol.md is the contract: elapsed time s
-in native steps from the right turning point, paper phase
-phi = (360 s / T - 90) mod 360, paper cycle k >= 1 spans
-s/T in [0.25 + (k-1), 0.25 + k); cycle 0 is the startup quarter.
-"""
-from __future__ import annotations
-
-import math
-from functools import lru_cache
-
-import numpy as np
-
-KC, RE = 5.0, 100.0
-STATIONS = (-0.6, 0.0, 0.6, 1.2)          # lab-fixed x/D from the mean position
-PHASES = (180.0, 210.0, 330.0)            # degrees; bins [p, p + 1)
-X2 = tuple(np.round(np.arange(-1.5, 1.5001, 0.05), 10))  # declared x2/D points
-DISCARD, LAST_SCORED, N_PAIRS = 2, 11, 3   # cycles 0..2 discarded, cap 12 T
-# A-priori bands. Settling is one fifth of the tightest comparison band of the
-# same observable, and comparisons add both cases' residual window drift
-# (conservative: |difference| + drift_a + drift_b <= band).
-DOMAIN = dict(wave=.01, morison=.02, profile=.02)  # vs the 60 D reference at D = 40
-CROSS = dict(wave=.02, profile=.02)                # D40 vs D80
-SETTLE = dict(wave=.002, scalar=.002, profile=.004, morison=.004)
-
-
-def amplitude(D):
-    return KC * D / (2.0 * math.pi)
-
-
-def position(s, T, A):
-    """Centre position relative to the mean: x = A cos(2 pi s / T), evaluated from the
-    native step modulo T so every cycle repeats the same geometry bit for bit."""
-    return A * math.cos(2.0 * math.pi * (int(s) % T) / T)
-
-
-def phase(s, T):
-    """Paper phase in degrees from the native step modulo T (the unwrapped cycle
-    index is kept separately by ``cycle``)."""
-    return (360.0 * (int(s) % T) / T - 90.0) % 360.0
-
-
-def cycle(s, T):
-    return 0 if s < 0.25 * T else int(math.floor(s / T - 0.25)) + 1
-
-
-def bin_phase(s, T):
-    """Scored phase whose 1-degree bin [p, p + 1) contains time s, else None."""
-    phi = phase(s, T)
-    for p in PHASES:
-        if p <= phi < p + 1.0:
-            return p
-    return None
-
-
-@lru_cache(maxsize=8)
-def _quadrature_rule(points):
-    """Reuse the nodes and weights, which depend only on quadrature order."""
-    return np.polynomial.legendre.leggauss(points)
-
-
-def interval_bases(n, T, points=16):
-    """Single-step interval averages over [n, n + 1] of cos phi |cos phi| and sin phi
-    (phi in radians = 2 pi s / T - pi / 2), Gauss-Legendre quadrature."""
-    x, w = _quadrature_rule(points)
-    s = int(n) % T + 0.5 * (x + 1.0)  # periodic: identical bases in every cycle
-    phi = 2.0 * np.pi * s / T - 0.5 * np.pi
-    c = np.cos(phi)
-    return 0.5 * float(np.sum(w * c * np.abs(c))), 0.5 * float(np.sum(w * np.sin(phi)))
-
-
-def morison_fit(f_norm, b1, b2):
-    """Least squares of f_norm = c_d b1 - (pi^2 c_i / KC) b2 (paper phase, no shift)."""
-    a = np.column_stack([b1, -(math.pi ** 2 / KC) * np.asarray(b2)])
-    (c_d, c_i), *_ = np.linalg.lstsq(a, np.asarray(f_norm), rcond=None)
-    return float(c_d), float(c_i)
-
-
-def inside_circle(x, y, centre, radius):
-    return (x - centre[0]) ** 2 + (y - centre[1]) ** 2 < radius * radius
-
-
-def sample(field, fluid, x, y, centre, radius):
-    """Profile sample: MISSING if the exact point is inside the body (checked before
-    any corner interpolation), else ``bilinear_fluid``."""
-    if inside_circle(x, y, centre, radius):
-        return None, (), 0.0
-    return bilinear_fluid(field, fluid, x, y)
-
-
-def bilinear_fluid(field, fluid, x, y):
-    """Bilinear value at (x, y) in cell coordinates from fluid cells only.
-
-    Returns (value, ((ix, iy, weight), ...), fluid_weight_sum) with weights
-    renormalized over the fluid corners and the original sum of their bilinear
-    weights, or (None, (), 0.0) when no corner is fluid (MISSING, never zero).
-    """
-    x0, y0 = int(math.floor(x)), int(math.floor(y))
-    fx, fy = x - x0, y - y0
-    corners = ((x0, y0, (1 - fx) * (1 - fy)), (x0 + 1, y0, fx * (1 - fy)),
-               (x0, y0 + 1, (1 - fx) * fy), (x0 + 1, y0 + 1, fx * fy))
-    used = [(i, j, w) for i, j, w in corners if w > 0.0 and fluid[j, i]]
-    total = sum(w for _, _, w in used)
-    if total == 0.0:
-        return None, (), 0.0
-    used = tuple((i, j, w / total) for i, j, w in used)
-    return float(sum(w * field[j, i] for i, j, w in used)), used, float(total)
-
-
-def settled_start(pairs_pass):
-    """K_case from {k: pass of pair (k-1 -> k)}: first cycle after three consecutive
-    passing pairs among cycles > DISCARD, or None."""
-    run = 0
-    for k in sorted(pairs_pass):
-        if k - 1 <= DISCARD:
-            continue
-        run = run + 1 if pairs_pass[k] else 0
-        if run == N_PAIRS:
-            return k + 1
-    return None
-
-
-def common_window(k_cases, pairs_pass_by_case, last_scored=LAST_SCORED):
-    """Common scored cycles K..K+2 with K = max K_case, or None (FAIL-CLOSED) when a
-    case never settled, K + 2 exceeds the cap, or a case fails any pair p_j for
-    j = its own K_case .. K + 2 (continuous settling, including the wait for K)."""
-    if any(k is None for k in k_cases):
-        return None
-    K = max(k_cases)
-    if K + 2 > last_scored:
-        return None
-    for k_case, pairs in zip(k_cases, pairs_pass_by_case):
-        if not all(pairs.get(j, False) for j in range(k_case, K + 3)):
-            return None
-    return K, K + 1, K + 2
@@ -1,133 +0,0 @@
-"""One-shot Dütsch Re 100 / KC 5 prescribed in-line oscillation driver.
-
-Protocol: docs/validation/duetsch_re100_kc5_protocol.md. Native dense channel
-(zero-velocity inlet, pressure-NEQ outlet, bounce-back y walls), MRT, lab frame.
-Writes raw per-step force/diagnostics and phase-bin profile samples to --out
-(outside the checkout); analysis is in analyze.py. No production change.
-
-    python run.py --D 40 --box 40 --cycles 11 --out /path/outside/checkout
-"""
-from __future__ import annotations
-
-import argparse
-import json
-import math
-import os
-import tempfile
-
-import numpy as np
-
-import protocol as p
-
-
-TEMPLATE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "..", "src",
-                        "CelerisLab", "configs", "config_lbm.json")
-
-
-def config(D, box, T):
-    """Shipped config_lbm.json (full parser schema) with only the case fields
-    overridden: grid, still fluid (velocity 0), nu from Re, MRT, uniform inlet
-    profile, bounce-back y walls. Inlet scheme and outlet mode stay the
-    template's (zou_he_local, neq_extrap) and are recorded in case.json."""
-    u = p.KC * D / T
-    n = int(round(box * D))
-    with open(TEMPLATE) as fh:
-        cfg = json.load(fh)
-    cfg["grid"].update(lattice_model="D2Q9", nx=n, ny=n, nz=1)
-    cfg["physics"].update(data_type="FP32", viscosity=u * D / p.RE, velocity=0.0, rho=1.0)
-    cfg["method"].update(collision="MRT", streaming="double_buffer", store_precision="FP32",
-                         ddf_shifting=False, y_wall_bc="bounce_back")
-    cfg["method"]["les"]["enabled"] = False
-    cfg["method"]["inlet"]["profile"] = "uniform"
-    return cfg, u, n
-
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument("--D", type=int, required=True)
-    ap.add_argument("--box", type=float, default=40.0, help="box side in D")
-    ap.add_argument("--T", type=int, default=None, help="period in steps (multiple of 360)")
-    ap.add_argument("--cycles", type=int, default=p.LAST_SCORED, help="run to the end of this cycle")
-    ap.add_argument("--out", required=True)
-    ap.add_argument("--dump-fields", default="",
-                    help="research capture: comma-separated paper cycles, e.g. 11,21,30,31")
-    args = ap.parse_args()
-    D, T = args.D, args.T or 126 * args.D
-    if T % 360:
-        raise SystemExit("T must be a multiple of 360 steps")
-    if os.path.realpath(args.out).startswith(os.path.realpath(os.path.join(os.path.dirname(__file__), "..", ".."))):
-        raise SystemExit("--out must be outside the checkout")
-    cfg, u_max, n = config(D, args.box, T)
-    A, R = p.amplitude(D), 0.5 * D
-    xm = ym = 0.5 * (n - 1)
-    os.makedirs(args.out, exist_ok=True)
-
-    from CelerisLab.body.motion import Translation
-    from CelerisLab.simulation import Simulation
-    with tempfile.NamedTemporaryFile("w", suffix=".json", delete=False) as fh:
-        json.dump(cfg, fh)
-    sim = Simulation(fh.name)
-    try:
-        body = sim.add_body("circle", (xm + A, ym), R,
-                            translation=Translation((-2.0 * A, 0.0, 0.0, 0.0), 1.01 * u_max))
-        sim.initialize()
-        dump = {int(c) for c in args.dump_fields.split(",") if c}
-        if dump:
-            import capture
-            if max(dump) > args.cycles or min(dump) <= p.DISCARD:
-                raise SystemExit("--dump-fields cycles must lie in the scored range of this run")
-            crop = capture.crop_box(xm, ym, D, n, (xm - A - R, xm + A + R, ym - R, ym + R))
-            trend = []
-        steps = int(round((0.25 + args.cycles) * T))
-        force = np.zeros((steps, 2)); diag = []; samples = []
-        for m in range(steps):
-            x0, x1 = p.position(m, T, A), p.position(m + 1, T, A)
-            sim.set_body(body, offset=(max(x1 - A, -2.0 * A), 0.0), vx=x1 - x0)
-            sim.run(1)
-            force[m] = sim.read_force(body)[:2]
-            diag.append(sim.moving_diagnostics()[0])
-            s = m + 1  # state after the step
-            ph = p.bin_phase(s, T)
-            if ph is not None and p.cycle(s, T) > p.DISCARD:
-                fields = sim.get_macroscopic()
-                fluid = (sim.get_flags().reshape(n, n) & 1) != 0
-                ux, uy = (np.asarray(fields[k]).reshape(n, n) for k in ("ux", "uy"))
-                if dump:  # research capture only; the default path is unchanged
-                    rho = np.asarray(fields["rho"]).reshape(n, n)
-                    trend.append(capture.trend_row(s, p.cycle(s, T), ph, rho, ux, uy, fluid, D, n, crop))
-                    if p.cycle(s, T) in dump and p.phase(s, T) == ph:  # first step of the bin
-                        x0c, x1c, y0c, y1c = crop
-                        cy_, cx_ = slice(y0c, y1c + 1), slice(x0c, x1c + 1)
-                        np.savez_compressed(
-                            os.path.join(args.out, f"fields_c{p.cycle(s, T)}_p{int(ph)}.npz"),
-                            s=s, cycle=p.cycle(s, T), phase=ph, crop=np.asarray(crop),
-                            force=force[m], centre=np.asarray((xm + p.position(s, T, A), ym)),
-                            ux=ux[cy_, cx_].astype(np.float32), uy=uy[cy_, cx_].astype(np.float32),
-                            rho=rho[cy_, cx_].astype(np.float32), fluid=fluid[cy_, cx_].astype(np.uint8),
-                            down_ux=capture.downsample(ux, fluid), down_uy=capture.downsample(uy, fluid),
-                            down_rho=capture.downsample(rho, fluid))
-                centre = (xm + p.position(s, T, A), ym)  # analytic centre after the step
-                for xs in p.STATIONS:
-                    for x2 in p.X2:
-                        x, y = xm + xs * D, ym + x2 * D
-                        u, wu, wsum = p.sample(ux, fluid, x, y, centre, R)
-                        v, _, _ = p.sample(uy, fluid, x, y, centre, R)
-                        samples.append((s, p.cycle(s, T), ph, xs, x2,
-                                        math.nan if u is None else u, math.nan if v is None else v,
-                                        wsum, json.dumps(wu)))
-        if dump:
-            np.save(os.path.join(args.out, "trend.npy"), np.asarray(trend, float))
-        np.savez(os.path.join(args.out, "raw.npz"), force=force, diag=np.asarray(diag),
-                 samples=np.asarray([r[:8] for r in samples], float))
-        with open(os.path.join(args.out, "case.json"), "w") as fh:
-            json.dump(dict(D=D, T=T, box=args.box, n=n, u_max=u_max, nu=cfg["physics"]["viscosity"],
-                           tau=3 * cfg["physics"]["viscosity"] + 0.5, A=A, steps=steps,
-                           cycles=args.cycles, F_ref=0.5 * u_max ** 2 * D,
-                           inlet=cfg["method"]["inlet"], outlet=cfg["method"]["outlet"],
-                           weights=[r[8] for r in samples]), fh)
-    finally:
-        sim.close()
-
-
-if __name__ == "__main__":
-    main()
@@ -1,332 +0,0 @@
-"""One paired zero/PPO Karman pinball VIV experiment; see docs/karman_viv.md.
-
-Research-only adapter: static precursor -> two fresh, identical moving plants.
-No moving checkpoint/rollback, policy retraining, or force filtering.
-"""
-from __future__ import annotations
-
-import argparse
-import hashlib
-import json
-from pathlib import Path
-import subprocess
-import sys
-import time
-
-import numpy as np
-
-ROOT = Path(__file__).resolve().parents[2]
-sys.path.insert(0, str(ROOT))
-from research.steady_pinball.run import Structure, config, scaled_points, CENTRES, PROBES, COLUMNS
-
-BIAS = np.array([0., -4., 4.])
-MODEL_SHA = '148240c1dcb8b11d8e5a0a9e991f6874c4e799c9744707bf0fb32a8efeb0468d'
-NORM_SHA = '534fda818c030a56960e95d0f3ac1e350d887d03db7f80f1d6453195a502b7f0'
-RELEASE_SOURCE = '516975ef6482f983ace347cb10de7450d2fbd680'
-STEP_COLUMNS = (*COLUMNS, 'omega_F', 'omega_U', 'omega_L')
-
-
-def sha(path):
-    h = hashlib.sha256()
-    with open(path, 'rb') as f:
-        for block in iter(lambda: f.read(1024*1024), b''):
-            h.update(block)
-    return h.hexdigest()
-
-
-def array_sha(a):
-    return hashlib.sha256(memoryview(np.ascontiguousarray(a)).cast('B')).hexdigest()
-
-
-def observation(sensor_mean, force_mean, scale, norm):
-    """Fine-grid area means/CME -> trained D20 sensor sums/forces -> frozen norm."""
-    sensors = np.asarray(sensor_mean, np.float64)*scale*78.
-    forces = np.asarray(force_mean, np.float64)*scale
-    raw = np.asarray([*sensors, *forces], np.float32)
-    preclip = np.hstack((raw[6:]/norm['force_norm_fact'],
-                        (raw[:6]-np.asarray(norm['sens_deviation'], np.float32)) /
-                        np.asarray(norm['sens_norm_fact'], np.float32)))
-    if not np.isfinite(preclip).all():
-        raise RuntimeError('nonfinite policy observation')
-    return raw, np.clip(preclip, -1, 1).astype(np.float32), int((np.abs(preclip)>1).sum())
-
-
-def wall_target(action, scale):
-    return (8.*np.asarray(action)+BIAS)*(.01/scale)
-
-
-def ema(eff, target, scale):
-    alpha = .9**(1./scale**2)
-    return alpha*eff + (1.-alpha)*target
-
-
-def load_policy(model):
-    # Same inference spaces as legacy_test.core.model_loader, without importing it.
-    import gymnasium as gym
-    from stable_baselines3 import PPO
-    class InferenceEnv(gym.Env):
-        observation_space = gym.spaces.Box(-1., 1., (12,), np.float32)
-        action_space = gym.spaces.Box(-1., 1., (3,), np.float32)
-        def reset(self, *, seed=None, options=None):
-            super().reset(seed=seed)
-            return np.zeros(12, np.float32), {}
-        def step(self, action):
-            return np.zeros(12, np.float32), 0., False, False, {}
-    return PPO.load(str(model), env=InferenceEnv(), device='cpu')
-
-
-def add_scene(sim, scale, moving=False, pinball=True):
-    from CelerisLab.body.motion import Translation
-    sim.add_body('circle', scaled_points(((200., 255.5),), scale)[0], 20.*scale)
-    probes = [sim.add_body('sensor', c, 5.*scale) for c in scaled_points(PROBES, scale)]
-    bodies = []
-    if pinball:
-        envelope = Translation((0., 0., -20.*scale, 20.*scale), .05/scale, shared=True) if moving else None
-        bodies = [sim.add_body('circle', c, 10.*scale, translation=envelope)
-                  for c in scaled_points(CENTRES, scale)]
-    return probes, bodies
-
-
-def capture_seed(sim):
-    """Capture both FP32 buffers at fixed geometry; never a moving-state checkpoint."""
-    import pycuda.driver as cuda
-    with sim.ctx.activate():
-        sim.stream.synchronize()
-        buffers = [np.empty_like(sim.field.ddf) for _ in range(2)]
-        for dst, src in zip(buffers, (sim.field.ddf_gpu, sim.field.temp_gpu)):
-            cuda.memcpy_dtoh(dst, src)
-    return (*buffers, sim.get_flags(), sim.stepper.step_count)
-
-
-def install_seed(sim, seed):
-    """Only a new, zero-offset instance may receive the static release state."""
-    import pycuda.driver as cuda
-    current, spare, flags, clock = seed
-    if sim.stepper.step_count != 0 or any(a.shape != sim.field.ddf.shape or a.dtype != sim.field.ddf.dtype
-                                         for a in (current, spare)):
-        raise ValueError('release transfer requires a fresh matching field')
-    if not np.array_equal(sim.get_flags(), flags):
-        raise ValueError('static/moving release flags differ')
-    for obj in sim.bodies.objects:
-        if obj.motion is not None and (obj.motion.applied != (0., 0.) or obj.motion.pending is not None):
-            raise ValueError('release transfer requires zero geometry and no target')
-    with sim.ctx.activate():
-        sim.stream.synchronize()
-        cuda.memcpy_htod(sim.field.ddf_gpu, current)
-        cuda.memcpy_htod(sim.field.temp_gpu, spare)
-    sim.stepper._step_count = clock  # one-time research initialization, not restore()
-    sim.field.invalidate_host_ddf_cache()
-    copied = capture_seed(sim)
-    if copied[3] != clock or any(not np.array_equal(a, b, equal_nan=True) for a, b in zip(copied[:3], seed[:3])):
-        raise RuntimeError('release transfer did not preserve both buffers/flags')
-    return dict(current=array_sha(copied[0]), spare=array_sha(copied[1]), flags=array_sha(copied[2]), clock=copied[3])
-
-
-def check_time(start, cap):
-    if time.monotonic()-start > cap:
-        raise TimeoutError('paired experiment wall cap')
-
-
-def warmup(sim, count, start, cap):
-    while count:
-        check_time(start, cap)
-        n = min(count, 10000)
-        sim.run(n)
-        count -= n
-
-
-def precursor(cfgpath, scale, warm, si, targets, out, start, cap):
-    from CelerisLab import Simulation
-    with Simulation(str(cfgpath)) as sim:
-        probes, _ = add_scene(sim, scale, pinball=False)
-        sim.initialize()
-        warmup(sim, warm, start, cap)
-        target = []
-        for _ in range(targets):
-            check_time(start, cap)
-            sim.run(si)
-            target.append([v*scale*78. for p in probes for v in sim.read_sensor(p)[:2]])
-        np.save(out/'target.npy', np.asarray(target, np.float32))
-        first = sim.bodies.count
-        for c in scaled_points(CENTRES, scale):
-            sim.add_body('circle', c, 10.*scale)
-        sim.sync_bodies()
-        bodies = list(range(first, first+3))
-        warmup(sim, warm-1, start, cap)
-        sim.run(1)
-        force = sum(float(sim.read_force(p)[1]) for p in bodies)
-        seed = capture_seed(sim)
-        np.savez(out/'release.npz', current=seed[0], spare=seed[1], flags=seed[2], clock=seed[3], force=force)
-        print(json.dumps(dict(event='precursor_complete', clock=seed[3], force=force,
-                              elapsed_s=time.monotonic()-start)), flush=True)
-        return seed, force
-
-
-def run_arm(name, cfgpath, scale, si, intervals, seed, initial_force, model, norm, out, start, cap, *, mass_ratio=2.):
-    from CelerisLab import Simulation
-    from CelerisLab.body.motion import MovingTables
-    cols = {k:i for i, k in enumerate(MovingTables.DIAG)}
-    diameter = 20.*scale
-    structure = Structure(mass_ratio, 1.e-4/scale**2, 0., diameter)
-    arm = out/name
-    arm.mkdir()
-    rows = np.lib.format.open_memmap(arm/'steps.npy', mode='w+', dtype=np.float64,
-                                    shape=(si*intervals, len(STEP_COLUMNS)))
-    rows[:] = np.nan
-    signals = {k:np.full((intervals, width), np.nan, np.float32) for k, width in
-               [('sensors',6), ('forces',6), ('actions',3), ('observations',12)]}
-    completed = completed_intervals = clipped = 0
-    status, transfer = 'running', None
-    force = initial_force
-    obs = np.zeros(12, np.float32)
-    arm_start = time.monotonic()
-    try:
-        with Simulation(str(cfgpath)) as sim:
-            probes, bodies = add_scene(sim, scale, moving=True)
-            sim.initialize()
-            transfer = install_seed(sim, seed)
-            for i in range(intervals):
-                action = -BIAS/8 if name == 'zero' else np.asarray(model.predict(obs, deterministic=True)[0], np.float32)
-                if action.shape != (3,) or not np.isfinite(action).all() or (np.abs(action)>1).any():
-                    raise RuntimeError('invalid policy action')
-                target, eff = wall_target(action, scale), np.zeros(3)
-                sensor_sum, force_sum = np.zeros(6), np.zeros(6)
-                for k in range(si):
-                    if k % 1000 == 0:
-                        check_time(start, cap)
-                    y1, v1 = structure.candidate(force)
-                    if not np.isfinite([y1,v1]).all() or abs(y1)>diameter:
-                        raise RuntimeError('nonfinite structure or |y| > D; no retuning')
-                    eff = ema(eff, target, scale)
-                    omega = eff/(diameter/2)
-                    for p, w in zip(bodies, omega):
-                        sim.set_body(p, omega=float(w), offset=(0., y1), vy=y1-structure.y)
-                    sim.run(1, zero_obs=True, sync_obs=True)
-                    d = sim.moving_diagnostics()
-                    cme, wen = d[:,cols['cme_y']], d[:,cols['wen_y']]
-                    node = d[:,cols['cover_jy']]-d[:,cols['uncover_jy']]
-                    row = (completed+1,y1,v1,*cme,*wen,*node,
-                           d[:,cols['eq_only']].sum(),d[:,cols['no_donor']].sum(),d[:,cols['crossings']].sum(),*omega)
-                    if not np.isfinite(row).all() or row[13] != 0:
-                        raise RuntimeError('nonfinite moving diagnostic or no_donor')
-                    f = np.array([v for p in bodies for v in sim.read_force(p)[:2]])
-                    s = np.array([v for p in probes for v in sim.read_sensor(p)[:2]])
-                    if not np.isfinite([f,s]).all():
-                        raise RuntimeError('nonfinite force/sensor observation')
-                    # Policy sees packed CME as in fixed-body training; structure sees CME+Wen.
-                    force_sum += f
-                    sensor_sum += s
-                    force = float(cme.sum(dtype=np.float64)+wen.sum(dtype=np.float64))
-                    rows[completed] = row
-                    completed += 1
-                    structure.y, structure.v = y1,v1
-                raw, obs, nclip = observation(sensor_sum/si, force_sum/si, scale, norm)
-                clipped += nclip
-                for key, val in [('sensors',raw[:6]),('forces',raw[6:]),('actions',action),('observations',obs)]:
-                    signals[key][i] = val
-                completed_intervals = i+1
-                if (i+1)%10 == 0 or i+1 == intervals:
-                    rows.flush()
-                    np.savez(arm/'signals.npz', **signals)
-                    print(json.dumps(dict(event='progress', arm=name, interval=i+1, step=completed,
-                                          tU_D=completed*.01/scale/diameter, y_D=y1/diameter,
-                                          elapsed_s=time.monotonic()-arm_start)), flush=True)
-            status = 'duration_completed_not_qualified'
-    except BaseException as exc:
-        status = f'error: {type(exc).__name__}: {exc}'
-        raise
-    finally:
-        rows.flush()
-        np.savez(arm/'signals.npz', **signals)
-        report = dict(status=status, completed_steps=completed, completed_intervals=completed_intervals,
-                      elapsed_s=time.monotonic()-arm_start, release_transfer=transfer, clipped_observation_channels=clipped,
-                      columns=STEP_COLUMNS, M=structure.mass,K=structure.stiffness,fn=structure.frequency,damping=0.,
-                      max_abs_y_D=float(np.max(np.abs(rows[:completed,1]))/diameter) if completed else None)
-        (arm/'report.json').write_text(json.dumps(report,indent=2)+'\n')
-
-
-def saved_release(directory):
-    """Read the retained m*=2 static release; not a moving-state restart."""
-    case = json.loads((directory/'case.json').read_text())
-    expected = dict(source=RELEASE_SOURCE, model_sha256=MODEL_SHA, norm_sha256=NORM_SHA,
-                    smoke=False, D=40, U=.005, nu=.004, warmup_each=2048000,
-                    target_intervals=150, SI=3200)
-    if any(case.get(k) != v for k, v in expected.items()):
-        raise ValueError('saved release case does not match the frozen precursor')
-    if json.loads((directory/'config.json').read_text()) != config(40):
-        raise ValueError('saved release config differs')
-    with np.load(directory/'release.npz') as data:
-        seed = (data['current'], data['spare'], data['flags'], int(data['clock']))
-        force = float(data['force'])
-    transfer = json.loads((directory/'zero/report.json').read_text())['release_transfer']
-    if seed[3] != transfer['clock'] or seed[3] != 4576000 or not np.isfinite(force):
-        raise ValueError('saved release clock/force differs')
-    if [array_sha(a) for a in seed[:3]] != [transfer[k] for k in ('current','spare','flags')]:
-        raise ValueError('saved release buffer/flags hash differs')
-    target = np.load(directory/'target.npy')
-    if target.shape != (150,6) or not np.isfinite(target).all():
-        raise ValueError('saved target is incomplete or nonfinite')
-    return seed, force
-
-
-def main():
-    ap = argparse.ArgumentParser(description=__doc__)
-    ap.add_argument('--model', type=Path, required=True)
-    ap.add_argument('--norm', type=Path, required=True)
-    ap.add_argument('--out', type=Path, required=True)
-    ap.add_argument('--smoke', action='store_true', help='short plumbing only; no physical conclusion')
-    ap.add_argument('--mass-ratio', type=float, choices=(2.,4.), default=2.,
-                    help='4 is the single declared exploratory candidate; fn and damping unchanged')
-    ap.add_argument('--release-dir', type=Path, help='retained m*=2 precursor; skip warmup')
-    ap.add_argument('--wall-seconds', type=float, default=14400.)
-    args = ap.parse_args()
-    if not np.isfinite(args.wall_seconds) or args.wall_seconds<=0:
-        ap.error('positive finite wall cap required')
-    if args.release_dir is not None and args.smoke:
-        ap.error('saved physical release cannot be used for the plumbing smoke')
-    if sha(args.model)!=MODEL_SHA or sha(args.norm)!=NORM_SHA:
-        ap.error('model/normalizer must match frozen provenance')
-    out = args.out.resolve()
-    if out == ROOT or ROOT in out.parents:
-        ap.error('output must be outside checkout')
-    out.mkdir(parents=True, exist_ok=False)
-    norm = json.loads(args.norm.read_text())
-    model = load_policy(args.model)
-    scale = 2.
-    warm, si, targets, intervals = (32,8,2,4) if args.smoke else (2048000,3200,150,400)
-    cfgpath = out/'config.json'
-    cfgpath.write_text(json.dumps(config(40),indent=2)+'\n')
-    receipt = dict(source=subprocess.check_output(['git','-C',str(ROOT),'rev-parse','HEAD'],text=True).strip(),
-                   model_sha256=sha(args.model),norm_sha256=sha(args.norm),smoke=args.smoke,D=40,U=.005,nu=.004,
-                   warmup_each=warm,target_intervals=targets,SI=si,response_intervals=intervals,
-                   response_steps=si*intervals,response_tU_D=si*intervals*.005/40,
-                   rhs='previous native step sum CME_y+Wen_y; policy uses interval packed CME',
-                   probe_frame='lab-fixed; fine area mean * 2 * trained 78 cells',
-                   ema_native_alpha=.9**.25, structural_damping=0., mass_ratio=args.mass_ratio,
-                   exploratory=args.mass_ratio==4., columns=STEP_COLUMNS)
-    loaded = None
-    if args.release_dir is not None:
-        loaded = saved_release(args.release_dir)
-        cfgpath.write_bytes((args.release_dir/'config.json').read_bytes())
-        (out/'target.npy').write_bytes((args.release_dir/'target.npy').read_bytes())
-        receipt.update(release_dir=str(args.release_dir.resolve()), release_source=RELEASE_SOURCE,
-                       release_sha256=sha(args.release_dir/'release.npz'),
-                       warmup_executed=0, target_sha256=sha(out/'target.npy'))
-    (out/'case.json').write_text(json.dumps(receipt,indent=2)+'\n')
-    start = time.monotonic()
-    status = 'running'
-    try:
-        seed, force = loaded if loaded is not None else precursor(cfgpath,scale,warm,si,targets,out,start,args.wall_seconds)
-        for name in ('zero','controlled'):
-            run_arm(name,cfgpath,scale,si,intervals,seed,force,model,norm,out,start,args.wall_seconds,
-                    mass_ratio=args.mass_ratio)
-        status = 'smoke_completed' if args.smoke else 'pair_completed_not_qualified'
-    except BaseException as exc:
-        status = f'error: {type(exc).__name__}: {exc}'
-        raise
-    finally:
-        (out/'terminal.json').write_text(json.dumps(dict(status=status,elapsed_s=time.monotonic()-start),indent=2)+'\n')
-
-
-if __name__ == '__main__':
-    main()
@@ -1,49 +0,0 @@
-{
-    "_doc": "Legacy geometry Re_D=50, U0=0.01, SI=800 baseline (kar_legacy_re50d_u001)",
-    "grid": {
-        "lattice_model": "D2Q9",
-        "nx": 1280,
-        "ny": 512,
-        "nz": 1
-    },
-    "physics": {
-        "data_type": "FP32",
-        "viscosity": 0.004,
-        "velocity": 0.01,
-        "rho": 1.0
-    },
-    "method": {
-        "collision": "MRT",
-        "streaming": "double_buffer",
-        "store_precision": "FP32",
-        "ddf_shifting": false,
-        "les": {
-            "enabled": false,
-            "cs": 0.16,
-            "closed_form": true
-        },
-        "trt": {
-            "magic_param": 0.1875
-        },
-        "inlet": {
-            "profile": "parabolic",
-            "scheme": "regularized",
-            "regularized_neq_damp": 1.0
-        },
-        "outlet": {
-            "mode": "neq_extrap",
-            "backflow_clamp": true,
-            "blend_alpha": 0.7,
-            "srt_neq_damp": 0.5
-        },
-        "y_wall_bc": "bounce_back",
-        "omega_guard": {
-            "min": 0.01,
-            "max": 1.99
-        }
-    },
-    "cuda": {
-        "threads_per_block": 256,
-        "compute_capability": "auto"
-    }
-}
@@ -1,196 +0,0 @@
-"""Uncontrolled paper-geometry steady Re_D=50, one transverse assembly DOF.
-
-Three predeclared zero-damping structures; --smoke uses only 32 + 32 steps.
-See docs/steady_pinball_fiv.md for historical solver differences and new structure.
-"""
-from __future__ import annotations
-
-import argparse
-import json
-import math
-from pathlib import Path
-import subprocess
-import time
-
-import numpy as np
-
-D, U, NU = 20., .01, .004
-CENTRES = ((600., 255.5), (626., 270.5), (626., 240.5))
-PROBES = ((800., 295.5), (800., 255.5), (800., 215.5))
-WARMUP, STEPS, PERIOD = 512000, 600000, 10000
-STRUCTURES = {'Z0': (10., 1.e-4), 'M2': (2., 1.e-4), 'R2': (2., 6.e-5)}
-COLUMNS = ('step', 'y', 'v', 'cme_F', 'cme_U', 'cme_L', 'wen_F', 'wen_U', 'wen_L',
-           'node_F', 'node_U', 'node_L', 'eq_only', 'no_donor', 'crossings')
-ROOT = Path(__file__).resolve().parents[2]
-
-
-def config(diameter=D):
-    """Diffusive refinement preserves the inlet/outlet and half-grid y walls."""
-    scale = diameter / D
-    if diameter not in (20, 40, 60):
-        raise ValueError('diameter must be 20, 40 or 60')
-    cfg = json.loads(Path(__file__).with_name('config.json').read_text())
-    cfg['grid']['nx'] = round((cfg['grid']['nx'] - 1) * scale + 1)
-    cfg['grid']['ny'] = round((cfg['grid']['ny'] - 2) * scale + 2)
-    cfg['physics']['velocity'] = U / scale
-    return cfg
-
-
-def scaled_points(points, scale):
-    return tuple((scale*x, .5 + scale*(y-.5)) for x, y in points)
-
-
-class Structure:
-    """Exact damped oscillator update for a force held over dt=1; no force filter."""
-    def __init__(self, mass_ratio=10., frequency=1.e-4, zeta=0., diameter=D):
-        if not (math.isfinite(mass_ratio) and mass_ratio > 0. and
-                math.isfinite(frequency) and frequency > 0. and
-                math.isfinite(zeta) and 0. <= zeta < 1.):
-            raise ValueError('positive finite mass ratio/frequency and 0 <= zeta < 1 required')
-        self.mass_ratio, self.frequency = mass_ratio, frequency
-        self.mass = mass_ratio * 3. * math.pi * diameter * diameter / 4.
-        self.omega = 2. * math.pi * frequency
-        self.zeta = zeta
-        self.stiffness = self.mass * self.omega**2
-        self.damping = 2. * self.zeta * self.mass * self.omega
-        self.y = self.v = 0.
-        a = self.zeta * self.omega
-        wd = self.omega * math.sqrt(1. - self.zeta**2)
-        self.ec = math.exp(-a) * math.cos(wd)
-        self.es = math.exp(-a) * math.sin(wd) / wd
-        self.a = a
-
-    def candidate(self, force):
-        equilibrium = force / self.stiffness
-        z = self.y - equilibrium
-        return (equilibrium + (self.ec + self.a*self.es)*z + self.es*self.v,
-                -self.omega**2*self.es*z + (self.ec - self.a*self.es)*self.v)
-
-
-def summarize(rows, diameter=D, block_steps=10*PERIOD):
-    windows = []
-    for start in range(0, len(rows), block_steps):
-        block = rows[start:start + block_steps]
-        fy = block[:, 3:9].sum(axis=1)
-        windows.append(dict(start_step=int(block[0, 0]), end_step=int(block[-1, 0]),
-                            y_mean_D=float(block[:, 1].mean()/diameter),
-                            y_rms_D=float(np.sqrt(np.mean(block[:, 1]**2))/diameter),
-                            y_peak_D=float(np.abs(block[:, 1]).max()/diameter),
-                            fy_mean=float(fy.mean()), fy_rms=float(np.sqrt(np.mean(fy**2))),
-                            mean_power=float(np.mean(fy*block[:, 2]))))
-    return windows
-
-
-def main():
-    ap = argparse.ArgumentParser(description=__doc__)
-    ap.add_argument('--out', required=True, type=Path)
-    ap.add_argument('--fixed', action='store_true', help='same modern moving-path geometry held fixed')
-    ap.add_argument('--smoke', action='store_true', help='32+32 steps, no physical result')
-    ap.add_argument('--case', choices=STRUCTURES, default='Z0',
-                    help='predeclared structure; all cases have zero structural damping')
-    ap.add_argument('--D', type=int, choices=(20, 40, 60), default=20,
-                    help='diameter in cells; diffusive scaling, matched geometry and physical duration')
-    ap.add_argument('--wall-seconds', type=float, default=7200., help='whole-case wall-clock cap')
-    args = ap.parse_args()
-    if not math.isfinite(args.wall_seconds) or args.wall_seconds <= 0:
-        ap.error('--wall-seconds must be finite and positive')
-    scale, time_scale = args.D / D, (args.D // int(D))**2
-    velocity = U / scale
-    centres, probes = scaled_points(CENTRES, scale), scaled_points(PROBES, scale)
-    period = PERIOD*time_scale
-    out = args.out.resolve()
-    if out == ROOT or ROOT in out.parents:
-        ap.error('output must be outside the checkout')
-    out.mkdir(parents=True, exist_ok=False)
-    cfg = config(args.D)
-    (out/'config.json').write_text(json.dumps(cfg, indent=2)+'\n')
-    source = subprocess.check_output(['git', '-C', str(ROOT), 'rev-parse', 'HEAD'], text=True).strip()
-    mass_ratio, frequency = STRUCTURES[args.case]
-    s = Structure(mass_ratio, frequency/time_scale, zeta=0., diameter=args.D)
-    warmup, count = (32, 32) if args.smoke else (WARMUP*time_scale, STEPS*time_scale)
-    rows = np.lib.format.open_memmap(out/'steps.npy', mode='w+', dtype=np.float64,
-                                     shape=(count, len(COLUMNS)))
-    rows[:] = np.nan
-    from CelerisLab import Simulation
-    from CelerisLab.body.motion import MovingTables, Translation
-    names = MovingTables.DIAG
-    col = {k: names.index(k) for k in names}
-    status, completed, f_last = 'running', 0, 0.
-    started = time.monotonic()
-    report = dict(source=source, case=args.case, fixed=args.fixed, smoke=args.smoke, columns=COLUMNS,
-                  structure=dict(mass=s.mass, stiffness=s.stiffness, damping=s.damping,
-                                 mass_ratio_three_disks=s.mass_ratio,
-                                 zeta=s.zeta, fn=s.frequency, Tn=1./s.frequency, y0=0., v0=0.),
-                  warmup_steps=warmup, requested_steps=count, dt=1., D=args.D, U=velocity, nu=NU,
-                  relative_to_D20=dict(dx=1/scale, dt=1/time_scale),
-                  centres=centres, probes=probes, wall_planes=(.5, cfg['grid']['ny']-1.5),
-                  wall_cap_seconds=args.wall_seconds,
-                  duration_Tn=count*s.frequency, duration_tU_D=count*velocity/args.D,
-                  summary_block_steps=10*period,
-                  rhs='sum of three instantaneous CME_y + Wen_y, one-step lag, no filtering')
-    try:
-        with Simulation(str(out/'config.json')) as sim:
-            # Match Legacy object order; probes remain passive and fixed in the lab.
-            for c in probes:
-                sim.add_body('sensor', c, 5.*scale)
-            envelope = Translation((0., 0., -args.D, args.D), .05/scale, shared=True)
-            bodies = [sim.add_body('circle', c, args.D/2, translation=envelope) for c in centres]
-            sim.initialize()
-            # At release obtain the last instantaneous force, not a warmup average.
-            remaining = warmup - 1
-            while remaining:
-                if time.monotonic()-started > args.wall_seconds:
-                    raise TimeoutError('whole-case wall cap during warmup')
-                chunk = min(10000, remaining)
-                sim.run(chunk)
-                remaining -= chunk
-            sim.run(1)
-            d = sim.moving_diagnostics()
-            f_last = float(d[:, col['cme_y']].sum(dtype=np.float64) + d[:, col['wen_y']].sum(dtype=np.float64))
-            report['warmup_elapsed_s'] = time.monotonic()-started
-            print(json.dumps(dict(event='release', **report)), flush=True)
-            for n in range(count):
-                if n % 1000 == 0 and time.monotonic()-started > args.wall_seconds:
-                    raise TimeoutError('whole-case wall cap during response')
-                y1, v1 = (0., 0.) if args.fixed else s.candidate(f_last)
-                if not all(map(math.isfinite, (y1, v1))) or abs(y1) > args.D:
-                    status = 'stopped_nonfinite_or_travel_bound'
-                    break
-                if not args.fixed:
-                    for bid in bodies:
-                        sim.set_body(bid, offset=(0., y1), vy=y1-s.y)
-                sim.run(1)
-                d = sim.moving_diagnostics()
-                cme, wen = d[:, col['cme_y']], d[:, col['wen_y']]
-                node = d[:, col['cover_jy']] - d[:, col['uncover_jy']]
-                row = (n+1, y1, v1, *cme, *wen, *node,
-                       d[:, col['eq_only']].sum(), d[:, col['no_donor']].sum(), d[:, col['crossings']].sum())
-                if not np.isfinite(row).all() or row[-2] != 0:
-                    status = 'stopped_nonfinite_or_no_donor'
-                    break
-                rows[n] = row
-                completed = n+1
-                s.y, s.v = y1, v1
-                f_last = float(cme.sum(dtype=np.float64)+wen.sum(dtype=np.float64))
-                if completed % period == 0:
-                    rows.flush()
-                    print(json.dumps(dict(event='progress', step=completed, t_Tn=completed*s.frequency,
-                                          y_D=s.y/args.D, elapsed_s=time.monotonic()-started)), flush=True)
-            else:
-                status = 'smoke_completed' if args.smoke else 'duration_completed_not_qualified'
-    except BaseException as exc:
-        status = f'error: {type(exc).__name__}: {exc}'
-        raise
-    finally:
-        rows.flush()
-        report.update(status=status, completed_steps=completed, elapsed_s=time.monotonic()-started,
-                      windows=summarize(rows[:completed], args.D, 10*period),
-                      totals={key: float(rows[:completed, i].sum()) for key, i in
-                              [('eq_only', 12), ('no_donor', 13), ('crossings', 14)]},
-                      limitation='Uncontrolled development response only. No automatic settling, grid convergence, control or historical-solver equivalence claim.')
-        (out/'report.json').write_text(json.dumps(report, indent=2)+'\n')
-        print(json.dumps(report), flush=True)
-
-
-if __name__ == '__main__':
-    main()
@@ -1,23 +0,0 @@
-# Research VIV driver — coupling contract (not production)
-
-`run.py` couples a 1-DOF undamped spring–mass (`viv.py`) to the production
-moving-circle API. Everything specific to fluid–structure coupling lives here,
-not in `src/`.
-
- Per step: known (y_n, v_n) and the last completed force F_last → exact
-  harmonic candidate (y_{n+1}, v_{n+1}) → `set_body(offset=(0, y_{n+1}),
-  vy=y_{n+1} − y_n)` (interval wall velocity, lattice dt = 1) → `run(1)` →
-  commit y, v and F_last only after the step succeeded. One step of explicit
-  force lag (weak coupling); no sub-iteration.
- Structural RHS = CME + Wen (y), read from `moving_diagnostics()` by the
-  names in `MovingTables.DIAG`; raw CME, the `obs` force and node terms are
-  logged as diagnostics. This is a stage choice, not a validated force law.
- Production guarantees used: fail-closed target commit (synchronized step,
-  `no_donor == 0`), input rejection before mutation, a failed device step
-  marks the Simulation failed.
- Not provided, by design: device-resident structure state or batched
-  (multi-step) coupling, strong/sub-iterated coupling (would need state
-  rollback), more than one DOF. These are future work and would be a separate
-  execution path, not an abstraction over this driver.
- Recorded result and limits: `docs/validation/moving_bodies_stage1.md`;
-  predeclaration: `docs/validation/viv_re150_predeclare.md`.
@@ -1,136 +0,0 @@
-"""One-shot predeclared VIV run (docs/validation/viv_re150_predeclare.md).
-
-Re 150, U* = 5, m/(rho D^2) = 2, zeta = 0, D = 40 on a nominal 75 D x 60 D
-lattice (uniform inlet, NEQ outlet, free-slip y walls). The cylinder is at
-(30 D, (ny - 1)/2); y-wall planes are .5 and ny - 1.5 in lattice coordinates.
-Structural RHS = CME + Wen (diagnostics: raw CME, node terms).
-Research driver only: Simulation API, no production change.
-
-    PYTHONPATH=src python research/viv_re150/run.py --out /path/outside/checkout
-"""
-from __future__ import annotations
-
-import argparse
-import json
-import math
-import os
-import tempfile
-
-import numpy as np
-
-import viv
-
-D, U = 40, 0.04
-TEMPLATE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "..", "src",
-                        "CelerisLab", "configs", "config_lbm.json")
-
-
-def config(D=D, U=U):
-    nx, ny = 75 * D, 60 * D
-    with open(TEMPLATE) as fh:
-        cfg = json.load(fh)
-    cfg["grid"].update(lattice_model="D2Q9", nx=nx, ny=ny, nz=1)
-    cfg["physics"].update(data_type="FP32", viscosity=U * D / viv.RE, velocity=U, rho=1.0)
-    cfg["method"].update(collision="MRT", streaming="double_buffer", store_precision="FP32",
-                         ddf_shifting=False, y_wall_bc="free_slip")
-    cfg["method"]["les"]["enabled"] = False
-    cfg["method"]["inlet"]["profile"] = "uniform"
-    return cfg, nx, ny
-
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument("--out", required=True)
-    ap.add_argument("--D", type=int, default=D)
-    ap.add_argument("--smoke", action="store_true",
-                    help="plumbing smoke only: exactly --steps steps (<= 64), never scored")
-    ap.add_argument("--steps", type=int, default=0)
-    args = ap.parse_args()
-    if args.smoke != bool(args.steps) or args.steps > 64 or args.steps < 0:
-        raise SystemExit("--smoke requires --steps N with 1 <= N <= 64 (and only with --smoke)")
-    if args.D != D and not args.smoke:
-        raise SystemExit("the physical case is predeclared at D = 40")
-    if os.path.realpath(args.out).startswith(os.path.realpath(os.path.join(os.path.dirname(__file__), "..", ".."))):
-        raise SystemExit("--out must be outside the checkout")
-    os.makedirs(args.out, exist_ok=True)
-    for name in ("report.json", "steps.npy"):  # never overwrite earlier evidence
-        if os.path.exists(os.path.join(args.out, name)):
-            raise SystemExit(f"{args.out} already holds {name}; use a fresh output directory")
-    Dn = args.D
-    cfg, nx, ny = config(Dn)
-    s, cyc = viv.Structure(Dn, U), viv.Cycles(Dn)
-    T_n = 1.0 / s.f_n
-    step_cap, n_seed = int(round(viv.STEP_CAP_TN * T_n)), int(round(viv.SEED_TN * T_n))
-    quiet = int(round(5 * T_n))
-    if args.smoke:
-        step_cap = args.steps
-    centre = (30.0 * Dn, 0.5 * (ny - 1))
-
-    from CelerisLab.body.motion import MovingTables, Translation
-    col = {k: MovingTables.DIAG.index(k) for k in ("cme_y", "wen_y", "cover_jy", "uncover_jy", "no_donor")}
-    from CelerisLab.simulation import Simulation
-    with tempfile.NamedTemporaryFile("w", suffix=".json", delete=False) as fh:
-        json.dump(cfg, fh)
-    sim = Simulation(fh.name)
-    rows, status, seed_step, f_last = [], "running", None, 0.0
-    try:
-        body = sim.add_body("circle", centre, 0.5 * Dn,
-                            translation=Translation((0.0, 0.0, -1.5 * Dn, 1.5 * Dn), 0.5))
-        sim.initialize()
-        for n in range(step_cap):
-            # rows[k] holds the state y_{k+1}; the declared window is y_t, t in [n_seed - 5 T_n, n_seed)
-            if not args.smoke and n == n_seed and \
-                    max(abs(r[1]) for r in rows[n_seed - quiet - 1:n_seed - 1]) < viv.ELIGIBLE * Dn:
-                s.v += s.seed_velocity(Dn)         # after the quiet check, before the update
-                seed_step = n
-                cyc.discard_current()
-                cyc.reset_proof()
-            y1, v1 = s.candidate(f_last)
-            if not (math.isfinite(y1) and math.isfinite(v1)) or abs(y1) > viv.Y_LIMIT * Dn:
-                status = "fail_bound_or_nonfinite"
-                break
-            try:
-                sim.set_body(body, offset=(0.0, y1), vy=y1 - s.y)
-            except ValueError as exc:              # input rejection: stop, no retry
-                status = f"rejected: {exc}"
-                break
-            sim.run(1)                             # device failures raise and mark the Simulation failed
-            d = sim.moving_diagnostics()[0]
-            f_obs = sim.read_force(body)[1]
-            f_rhs = float(d[col["cme_y"]] + d[col["wen_y"]])   # CME + Wen (y)
-            row = (n, y1, v1, f_rhs, float(d[col["cme_y"]]), float(d[col["wen_y"]]), float(f_obs),
-                   float(d[col["cover_jy"]] - d[col["uncover_jy"]]), float(d[col["no_donor"]]))
-            if not viv.finite(row):                # every recorded output, not only the RHS
-                status = "fail_nonfinite_output"
-                break
-            s.y, s.v, f_last = y1, v1, f_rhs       # commit only after a successful step
-            rows.append(row)
-            if args.smoke:
-                continue                           # no settle / score in the plumbing smoke
-            if cyc.update(s.y) == "scored":
-                status = "scored"
-                break
-            if cyc.counted >= viv.CYCLE_CAP:
-                status = "timeout_response_cycles"
-                break
-        else:
-            status = ("smoke_ok" if all(r[8] == 0.0 for r in rows) else "smoke_no_donor") \
-                if args.smoke else "timeout_native_steps"
-    except BaseException as exc:
-        status = f"error: {exc!r}"
-        raise
-    finally:
-        np.save(os.path.join(args.out, "steps.npy"), np.asarray(rows, float))
-        report = dict(status=status, smoke=args.smoke, D=Dn, steps=len(rows), t_U_over_D=len(rows) * U / Dn, T_n=T_n,
-                      seed_step=seed_step, counted_cycles=cyc.counted, cycles=cyc.log,
-                      columns=["n", "y", "v", "F_rhs_cme_wen", "F_cme", "F_wen", "F_obs",
-                               "node_cover_minus_uncover_y", "no_donor"])
-        if status == "scored" and not args.smoke:
-            report["score"] = viv.score(cyc.window)
-        with open(os.path.join(args.out, "report.json"), "w") as fh:
-            json.dump(report, fh, indent=1)
-        sim.close()
-
-
-if __name__ == "__main__":
-    main()
@@ -1,126 +0,0 @@
-"""Pure logic of the predeclared Re 150 free transverse VIV case (stdlib only).
-
-Contract: docs/validation/viv_re150_predeclare.md. Oscillator update with a
-constant force over one lattice step, response-cycle tracking with fixed y = 0
-crossings, eligibility, 10-cycle blocks, settling/scoring with deterministic
-restart, and the conditional seed.
-"""
-from __future__ import annotations
-
-import math
-
-RE, U_STAR, MASS_NUMBER = 150.0, 5.0, 2.0      # m/(rho D^2) = 2 -> m* = 8/pi
-TARGET_A, BAND = 0.520, 0.10                   # Qin §4.5 maximum amplitude, ±10 %
-ELIGIBLE, BLOCK, LAST5 = 0.01, 10, 5           # in D; cycles; cycles
-WINDOW_TOL, LAST5_TOL = 0.02, 0.01
-CYCLE_CAP, STEP_CAP_TN, SEED_TN, Y_LIMIT = 150, 200, 40, 1.0
-
-
-def finite(values):
-    """True iff every recorded value is finite (fail-closed output check)."""
-    return all(math.isfinite(float(v)) for v in values)
-
-
-class Structure:
-    """Undamped spring-mass, exact harmonic update over dt = 1 with constant force."""
-
-    def __init__(self, D, u):
-        self.m = MASS_NUMBER * D * D           # lattice rho = 1
-        self.f_n = u / (U_STAR * D)
-        self.w = 2.0 * math.pi * self.f_n
-        self.k = self.m * self.w * self.w
-        self.y = self.v = 0.0
-
-    def candidate(self, force):
-        ye = force / self.k
-        c, s = math.cos(self.w), math.sin(self.w)
-        return (ye + (self.y - ye) * c + self.v / self.w * s,
-                -(self.y - ye) * self.w * s + self.v * c)
-
-    def seed_velocity(self, D):
-        return self.w * ELIGIBLE * D           # amplitude ~ .01 D
-
-
-class Cycles:
-    """Upward y = 0 crossings, eligibility, blocks, settle/score with restart."""
-
-    def __init__(self, D):
-        self.D = D
-        self.reset_proof()
-        self.counted = 0
-        self.log = []                          # one dict per completed cycle
-        self._cur = None
-        self._prev = 0.0
-        self._since = 0
-
-    def reset_proof(self):
-        self.amps = []                         # eligible amplitudes since proof start
-        self.blocks = []                       # block means
-        self.settled_at = None                 # block index where R held
-        self.window = None                     # completed scoring cycles (list of dicts)
-
-    def discard_current(self):
-        self._cur, self._since = None, 0
-
-    def rule(self, k):
-        """R(k): block-mean change ≤ 2 % and last-five spread ≤ 1 %."""
-        if k < 1:
-            return False
-        w0, w1 = self.blocks[k - 1], self.blocks[k]
-        last = self.amps[(k + 1) * BLOCK - LAST5:(k + 1) * BLOCK]
-        a5 = sum(last) / LAST5
-        return abs(w1 - w0) / w0 <= WINDOW_TOL and max(abs(a - a5) for a in last) / a5 <= LAST5_TOL
-
-    def update(self, y):
-        """Feed y after a committed step; returns 'scored' when a stable window completes."""
-        out = None
-        crossing = self._prev < 0.0 <= y and self._since >= 2
-        if crossing:
-            if self._cur is not None:
-                out = self._close()
-            self._cur, self._since = dict(ymax=y, ymin=y, ysum=0.0, n=0), 0
-        if self._cur is not None:
-            c = self._cur
-            c["ymax"], c["ymin"] = max(c["ymax"], y), min(c["ymin"], y)
-            c["ysum"] += y
-            c["n"] += 1
-        self._since += 1
-        self._prev = y
-        return out
-
-    def _close(self):
-        c = self._cur
-        a = 0.5 * (c["ymax"] - c["ymin"]) / self.D
-        cyc = dict(ymax=c["ymax"] / self.D, ymin=c["ymin"] / self.D,
-                   offset=c["ysum"] / c["n"] / self.D, amp=a, steps=c["n"], eligible=a >= ELIGIBLE)
-        self.log.append(cyc)
-        if not cyc["eligible"]:
-            return None
-        self.counted += 1
-        self.amps.append(a)
-        if self.settled_at is not None:
-            self.window.append(cyc)
-        if len(self.amps) % BLOCK:
-            return None
-        self.blocks.append(sum(self.amps[-BLOCK:]) / BLOCK)
-        k = len(self.blocks) - 1
-        if self.settled_at is None:
-            if self.rule(k):
-                self.settled_at, self.window = k, []
-            return None
-        if not self.rule(k):                   # scoring block failed: restart from it
-            amps, blocks = self.amps[-BLOCK:], self.blocks[-1:]
-            self.reset_proof()
-            self.amps, self.blocks = amps, blocks
-            return None
-        return "scored" if k == self.settled_at + 2 else None
-
-
-def score(window):
-    """Target metric and reported quantities over the 20 scoring cycles."""
-    a_max = max(max(abs(c["ymax"]), abs(c["ymin"])) for c in window)
-    return dict(A_max=a_max, mean_amp=sum(c["amp"] for c in window) / len(window),
-                ymax=max(c["ymax"] for c in window), ymin=min(c["ymin"] for c in window),
-                offset=sum(c["offset"] for c in window) / len(window),
-                T_resp=sum(c["steps"] for c in window) / len(window),
-                within_band=abs(a_max - TARGET_A) <= BAND * TARGET_A)
@@ -207,30 +207,22 @@ def surface_link_velocity(objects, cfg, flags, fluid_idx, dir, body_id, rx, ry,
                          jets=(), hits=None, *, _shifted_blocked=False):
    """Per-link prescribed surface velocity (n, 2) FP32 and aperture mask.

-    See _surface_links, which also returns the unit-amplitude jet shapes.
-    """
-    return _surface_links(objects, cfg, flags, fluid_idx, dir, body_id, rx, ry, jets, hits,
-                          _shifted_blocked=_shifted_blocked)[:2]
-
-
-def _surface_links(objects, cfg, flags, fluid_idx, dir, body_id, rx, ry,
-                   jets=(), hits=None, *, _shifted_blocked=False):
-    """(velocity, aperture, jet shape, jet id); the last two are None without jets.
-
    Host-only and storage-neutral: rows follow the given physical cut-link
-    order. Returns all None when neither an object carries surface
+    order. Returns (None, None) when neither an object carries surface
    actuation nor a jet is given. Jets need true FP64 ``hits`` (n, 2) and may
    not share a link with each other or with a legacy aperture.
    Shifted storage is privately enabled only by the all-blocked stepper.
    """
    enabled = [obj for obj in objects if obj.surface_actuation is not None]
    if not enabled and not jets:
-        return None, None, None, None
-    from .preprocess.flag_overlay import validate_cut_link_ownership
-    validate_cut_link_ownership(flags, fluid_idx, dir, cfg.nq)
+        return None, None
+    from ..lbm.descriptors import FLUID, SOLID
+    if np.any((flags[fluid_idx] & FLUID) == 0) or np.any(flags[fluid_idx] & SOLID):
+        raise ValueError("Surface cut links must have active fluid receivers")
+    if len(np.unique(fluid_idx.astype(np.uint64)*cfg.nq+dir)) != len(dir):
+        raise ValueError("Surface boundary requires unique cut-link writers")
    surface_velocity = np.zeros((len(dir), 2), np.float32)
    surface_aperture = np.zeros(len(dir), bool)
-    shape = jet_id = None
    for obj in enabled:
        obj.validate_surface_actuation(cfg)
        selected = body_id == obj.obj_id
@@ -263,4 +255,4 @@ def _surface_links(objects, cfg, flags, fluid_idx, dir, body_id, rx, ry,
            raise ValueError("Jet overlaps a SurfaceActuation aperture")
        surface_velocity[driven] = jet_link_velocity(jets, shape, jet_id)[driven]
        surface_aperture |= driven
-    return surface_velocity, surface_aperture, shape, jet_id
+    return surface_velocity, surface_aperture
@@ -11,7 +11,7 @@ Responsibilities:

 Design::
  Packed ``obs`` layout matches ``generate_config(..., n_objects=count)`` and
-  ``config_obs.h`` macros. Host sizing uses :func:`~CelerisLab.cuda.compiler.obs_layout`.
+  ``config_obs.h`` macros. Host sizing uses :func:`~CelerisLab.cuda.compiler_v2.obs_layout`.

  Pending edits are lightweight: only the "intent" (add / remove) is stored.
  All derived quantities (flags, compact lists, GPU buffers) are built at
@@ -27,8 +27,8 @@ import pycuda.driver as cuda

 from .objects import SimObject
 from .registry import BodyRegistry
-from .preprocess.flag_overlay import merge_flag_masks, validate_cut_link_ownership
-from ..cuda.compiler import obs_layout
+from .preprocess.flag_overlay import merge_flag_masks
+from ..cuda.compiler_v2 import obs_layout
 from ..cuda.obs_layout import ObsLayout
 from ..lbm.descriptors import (
    FLUID, SOLID,
@@ -369,9 +369,9 @@ class ObjectManager:

        Args:
            objects: List of SimObject instances to process.
-            domain_flags: Optional uint16 flags for receiver/donor classification.
+            domain_flags: Optional uint16 flags for donor-cell classification.
            sensor_cell_counts_out: Int array to fill with per-object sensor
-                cell counts after the full geometry has passed validation.
+                cell counts.  If provided, ``fill(0)`` is called first.
            hits_out: List that receives one FP64 (n, 2) array of true hit
                points row-aligned with the cut-link columns (for Jets).

@@ -394,8 +394,8 @@ class ObjectManager:
        active_fluid = ((domain_flags & FLUID) != 0) & ((domain_flags & SOLID) == 0)
        force_owners: set[int] = set()

-        sensor_counts = (np.zeros_like(sensor_cell_counts_out)
-                         if sensor_cell_counts_out is not None else None)
+        if sensor_cell_counts_out is not None:
+            sensor_cell_counts_out.fill(0)

        ez = None
        if self.cfg and self.cfg.is_d3q19:
@@ -405,9 +405,7 @@ class ObjectManager:

        for obj in objects:
            obj.validate_surface_actuation(self.cfg)
-            # Moving circles never enter the packed static links (docs/moving_bodies.md, section 3).
-            if (not obj.is_sensor) and (not obj.is_force_region) and obj.motion is None \
-                    and hasattr(obj, 'get_curved_list'):
+            if (not obj.is_sensor) and (not obj.is_force_region) and hasattr(obj, 'get_curved_list'):
                (
                    fluid_idx, dirs, q_vals, body_ids,
                    rx_vals, ry_vals, rz_vals, fallback_vals
@@ -432,9 +430,9 @@ class ObjectManager:
                if len(cells) > 0:
                    s_cells.append(cells)
                    s_ids.append(ids)
-                    if (sensor_counts is not None
-                            and 0 <= obj.obj_id < sensor_counts.size):
-                        sensor_counts[obj.obj_id] = int(len(cells))
+                    if (sensor_cell_counts_out is not None
+                            and 0 <= obj.obj_id < sensor_cell_counts_out.size):
+                        sensor_cell_counts_out[obj.obj_id] = int(len(cells))
            if obj.is_force_region and hasattr(obj, 'get_sensor_list'):
                cells, ids = obj.get_sensor_list(self.nx, self.ny, self.nz)
                keep = active_fluid[cells]
@@ -463,9 +461,8 @@ class ObjectManager:
        r_fr_ids = np.concatenate(fr_ids) if fr_ids else np.zeros(0, dtype=np.int32)

        r_hit = np.concatenate(cl_hit) if cl_hit else np.zeros((0, 2))
-        # Passive walls need the same ownership guarantees as driven walls.
-        # Overlapping solids are not a supported union-boundary operation.
-        validate_cut_link_ownership(domain_flags, r_idx, r_dir, self.nq)
+        if hits_out is not None:
+            hits_out.append(r_hit)
        if self.jets or any(obj.surface_actuation is not None for obj in objects):
            # Reject unresolved apertures/ownership before sync or restart mutates state.
            from ..lbm.curved_links import CurvedLinkSoA
@@ -473,11 +470,6 @@ class ObjectManager:
            links.assign_host(r_idx, r_dir, r_q, r_bid, r_rx, r_ry, r_rz, r_fallback)
            links.assign_surface(objects, self.cfg, domain_flags, jets=self.jets, hits=r_hit)

-        if sensor_cell_counts_out is not None:
-            sensor_cell_counts_out[:] = sensor_counts
-        if hits_out is not None:
-            hits_out.append(r_hit)
-
        return (
            r_idx, r_dir, r_q, r_bid,
            r_rx, r_ry, r_rz, r_fallback,
@@ -495,6 +487,8 @@ class ObjectManager:
                the caller has already prepared and uploaded the final flag field
                for this geometry, such as during initialization.
        """
+        self._telemetry_field = field
+
        next_flags = self.build_flags(field.build_channel_flags()) if rebuild_flags else field.flag
        hits = []

@@ -505,7 +499,6 @@ class ObjectManager:
            fr_cells, fr_obj_id,
        ) = self.build_compact_lists(domain_flags=next_flags, hits_out=hits)

-        self._telemetry_field = field
        if rebuild_flags:
            field.flag = next_flags
            field.upload_flags()
@@ -1,224 +0,0 @@
-# CelerisLab/body/motion.py
-"""Translation targets and device tables (dense double buffer, D2Q9 only).
-
-Contract: docs/moving_bodies.md, sections 4a, 5 and 7. The applied geometry
-(last successfully committed offset) and an optional pending target are two
-separate facts; centres are always ``base + offset``. MovingCircle owns host
-targets, MovingTables owns device records, and Simulation commits completed steps.
-"""
-from __future__ import annotations
-
-import math
-from dataclasses import dataclass
-from typing import Callable, Optional, Tuple
-
-MAX_STEP = 0.5     # Euclidean centre displacement per step (lattice cells)
-BAND_MARGIN = 2    # cells added around the swept circle AABB
-SHARED_CLEARANCE = 4.0  # > two diagonal links + MAX_STEP; docs/steady_pinball_fiv.md
-R_MIN = 4.0        # smallest radius covered by the donor enumeration
-
-Vec = Tuple[float, float]
-
-
-def _vec(value, name: str) -> Vec:
-    x, y = (float(v) for v in value)
-    if not (math.isfinite(x) and math.isfinite(y)):
-        raise ValueError(f"{name} must be finite, got {value!r}")
-    return x, y
-
-
-@dataclass(frozen=True)
-class Translation:
-    """Declared motion envelope: offset box (x_min, x_max, y_min, y_max) and speed bound."""
-    offset_box: Tuple[float, float, float, float]
-    max_speed: float
-    shared: bool = False  # same envelope instance: synchronous transverse motion
-
-    def __post_init__(self):
-        box = tuple(float(v) for v in self.offset_box)
-        speed = float(self.max_speed)
-        if len(box) != 4 or not all(math.isfinite(v) for v in box + (speed,)):
-            raise ValueError("offset_box needs 4 finite values and max_speed must be finite")
-        if not (box[0] <= 0.0 <= box[1] and box[2] <= 0.0 <= box[3]):
-            raise ValueError("offset_box must contain the zero offset")
-        if not 0.0 < speed <= MAX_STEP:
-            raise ValueError(f"max_speed must satisfy 0 < max_speed <= {MAX_STEP}")
-        if self.shared and box[:2] != (0.0, 0.0):
-            raise ValueError("shared translation is transverse only (x offsets must be zero)")
-        object.__setattr__(self, "offset_box", box)
-        object.__setattr__(self, "max_speed", speed)
-
-
-def validate_shared_translations(circles):
-    """Check common old/target offsets and wall velocities before device work.
-
-    Per-body setters may stage members in any order. Envelope identity (not
-    value equality) defines a group; a missing target means hold at applied.
-    """
-    groups = {}
-    for motion in circles:
-        if not motion.translation.shared:
-            continue
-        target = motion.pending if motion.pending is not None else (motion.applied, (0.0, 0.0))
-        state = (motion.applied, target)
-        key = id(motion.translation)
-        if groups.setdefault(key, state) != state:
-            raise ValueError("shared translation needs identical applied/target offsets and velocities")
-
-
-class MovingCircle:
-    """Applied offset, pending target and the fail-closed commit of one circle."""
-
-    def __init__(self, base, radius: float, translation: Translation,
-                 on_failure: Optional[Callable[[BaseException], None]] = None):
-        self.base = _vec(base, "base")
-        self.radius = float(radius)
-        if not (math.isfinite(self.radius) and self.radius >= R_MIN):
-            raise ValueError(f"moving circle radius must be >= {R_MIN}")
-        if not isinstance(translation, Translation):
-            raise TypeError("translation must be a Translation")
-        self.translation = translation
-        self.applied: Vec = (0.0, 0.0)
-        self.pending: Optional[Tuple[Vec, Vec]] = None
-        self.failed = False
-        self._on_failure = on_failure  # owner lifecycle hook (Simulation marks itself failed)
-
-    def centre(self, offset: Vec) -> Vec:
-        return self.base[0] + offset[0], self.base[1] + offset[1]
-
-    def check_target(self, offset, velocity) -> Tuple[Vec, Vec]:
-        """Validate a target against ``applied``; returns it, mutates nothing."""
-        self._require_usable()
-        offset, velocity = _vec(offset, "offset"), _vec(velocity, "velocity")
-        x0, x1, y0, y1 = self.translation.offset_box
-        if not (x0 <= offset[0] <= x1 and y0 <= offset[1] <= y1):
-            raise ValueError(f"offset {offset} outside declared box {self.translation.offset_box}")
-        if self.translation.shared and velocity[0] != 0.0:
-            raise ValueError("shared translation needs zero x velocity")
-        step = math.hypot(offset[0] - self.applied[0], offset[1] - self.applied[1])
-        if step > MAX_STEP:
-            raise ValueError(f"per-step displacement {step} exceeds {MAX_STEP}")
-        if math.hypot(*velocity) > self.translation.max_speed:
-            raise ValueError(f"velocity {velocity} exceeds max_speed {self.translation.max_speed}")
-        if offset == self.applied and velocity != (0.0, 0.0):
-            raise ValueError("a hold target (offset == applied) needs zero translational velocity")
-        return offset, velocity
-
-    def set_target(self, offset, velocity) -> None:
-        """Replace the pending target (last wins); invalid input keeps the old one."""
-        self.pending = self.check_target(offset, velocity)
-
-    def record(self) -> Tuple[Vec, Vec, Vec]:
-        """Motion record (c_old, c_new, u) for the next single moving step."""
-        self._require_usable()
-        if self.pending is not None:
-            offset, velocity = self.pending
-        else:
-            offset, velocity = self.applied, (0.0, 0.0)
-        return self.centre(self.applied), self.centre(offset), velocity
-
-    def commit(self) -> None:
-        """Applied := pending offset (caller has synchronized a successful step)."""
-        if self.pending is not None:
-            self.applied = self.pending[0]
-            self.pending = None
-
-    def fail(self, exc: BaseException) -> None:
-        self.failed = True
-        if self._on_failure is not None:
-            self._on_failure(exc)
-
-    def band(self) -> Tuple[int, int, int, int]:
-        """Inclusive cell AABB (x0, x1, y0, y1) swept over the whole offset box."""
-        x0, x1, y0, y1 = self.translation.offset_box
-        r, m = self.radius, BAND_MARGIN
-        return (math.floor(self.base[0] + x0 - r) - m, math.ceil(self.base[0] + x1 + r) + m,
-                math.floor(self.base[1] + y0 - r) - m, math.ceil(self.base[1] + y1 + r) + m)
-
-    def _require_usable(self) -> None:
-        if self.failed:
-            raise RuntimeError("moving circle state is unknown after a failed step")
-
-
-class MovingTables:
-    """Device tables of the translating circles for ``MovingCircleCells``/``Links``.
-
-    Band table (x0, y0, width, height, first_slot, body_id), immutable per run;
-    FP64 motion records (cx_old, cy_old, cx_new, cy_new, r, ux, uy), immutable
-    during a step; separate per-body diagnostics (see DIAG), never part of obs.
-    """
-    BAND_INTS, GEOM_DOUBLES = 6, 7
-    DIAG = ("cme_x", "cme_y", "wen_x", "wen_y", "link_dm", "n_links",
-            "cover_jx", "cover_jy", "cover_mass", "uncover_jx", "uncover_jy", "uncover_mass",
-            "eq_only", "no_donor", "crossings")
-    DIAG_FLOATS = len(DIAG)
-
-    def __init__(self, band, geom):
-        import numpy as np
-        import pycuda.driver as cuda
-        self.n_bodies = len(geom) // self.GEOM_DOUBLES
-        self.n_slots = int(band[-2] + band[-4] * band[-3] * 8)
-        self.n_cells = self.n_slots // 8
-        self.geom = list(geom)  # host copy of the uploaded records
-        self.band_gpu = cuda.to_device(np.asarray(band, np.int32))
-        self.geom_gpu = cuda.to_device(np.asarray(geom, np.float64))
-        # Owned page-locked staging for async record uploads (allocated once).
-        self._geom_pinned = cuda.pagelocked_empty(len(geom), np.float64)
-        self.diag_gpu = cuda.to_device(np.zeros(self.n_bodies * self.DIAG_FLOATS, np.float32))
-        self.slot_debug_gpu = None  # optional (q, fallback, rx, ry) per slot for parity tests
-
-    @classmethod
-    def upload(cls, circles):
-        """``circles``: [(MovingCircle, body_id)] in body order."""
-        return cls(*cls.layout(circles))
-
-    @staticmethod
-    def layout(circles):
-        """Host band and geometry tables (no device work)."""
-        band, geom, first = [], [], 0
-        for motion, body_id in circles:
-            x0, x1, y0, y1 = motion.band()
-            width, height = x1 - x0 + 1, y1 - y0 + 1
-            band += [x0, y0, width, height, first, int(body_id)]
-            first += width * height * 8
-            geom += MovingTables.record(motion)
-        return band, geom
-
-    @staticmethod
-    def record(motion):
-        """FP64 motion record of one circle for its next step (hold if nothing pending)."""
-        c_old, c_new, u = motion.record()
-        return [*c_old, *c_new, motion.radius, *u]
-
-    def upload_records(self, circles, stream) -> bool:
-        """Enqueue the records when they differ from the device copy; True if advancing.
-
-        The pinned staging buffer is reused: callers synchronize ``stream`` after every
-        upload before the next one (``Simulation._run_moving``), so no copy is in flight
-        when it is rewritten. ``geom`` is the enqueued state; after a failed copy the
-        owner is failed and the cache is never trusted again.
-        """
-        import pycuda.driver as cuda
-        geom = [v for motion, _ in circles for v in self.record(motion)]
-        if geom != self.geom:
-            self._geom_pinned[:] = geom
-            cuda.memcpy_htod_async(self.geom_gpu, self._geom_pinned, stream)
-            self.geom = geom
-        g = self.GEOM_DOUBLES
-        return any(geom[i:i + 2] != geom[i + 2:i + 4] for i in range(0, len(geom), g))
-
-    def enable_slot_debug(self):
-        import numpy as np
-        import pycuda.driver as cuda
-        self.slot_debug_gpu = cuda.to_device(np.zeros(self.n_slots * 4, np.float32))
-
-    def zero_diagnostics(self, stream):
-        import pycuda.driver as cuda
-        cuda.memset_d32_async(self.diag_gpu, 0, self.n_bodies * self.DIAG_FLOATS, stream)
-
-    def download_diagnostics(self):
-        import numpy as np
-        import pycuda.driver as cuda
-        out = np.empty((self.n_bodies, self.DIAG_FLOATS), np.float32)
-        cuda.memcpy_dtoh(out, self.diag_gpu)
-        return out
@@ -140,7 +140,6 @@ class SimObject:
            x=float(c[0]), y=float(c[1]), z=z0,
        )
        self.control = ObjectControl()
-        self.motion = None  # MovingCircle for a translating circle (body/motion.py)

    @property
    def surface_actuation(self):
@@ -1,6 +1,6 @@
 # CelerisLab/body/preprocess/flag_overlay.py
 """
-Flag overlay and cut-link ownership checks against the merged domain.
+Flag overlay: merge per-object flag masks onto a clean domain base.
 """

 from __future__ import annotations
@@ -12,15 +12,6 @@ import numpy as np
 from ...lbm.descriptors import FLUID, SOLID, SENSOR_FLAG, FRC_REGION


-def validate_cut_link_ownership(flags, fluid_idx, directions, nq):
-    """Reject solid receivers and multiple writers to one population."""
-    if np.any((flags[fluid_idx] & FLUID) == 0) or np.any(flags[fluid_idx] & SOLID):
-        raise ValueError("Cut links must have active fluid receivers")
-    writers = fluid_idx.astype(np.uint64) * nq + directions
-    if len(np.unique(writers)) != len(directions):
-        raise ValueError("Boundary requires unique cut-link writers")
-
-
 def merge_flag_masks(
    base: np.ndarray,
    masks: List[np.ndarray],
@@ -7,7 +7,7 @@ Two JSON files:
  config_body.json – object list

 LBMConfig / BodyConfig are plain dataclasses; they translate to
-macro dicts consumed by `cuda/compiler.py` for header generation.
+macro dicts consumed by `cuda/compiler_v2.py` for header generation.
 """

 import json
@@ -60,14 +60,14 @@ Python `config.py` 只负责读取和校验，不是配置位置。显式配置

 **`lbm/kernels/config/*.h` 由编译器根据 `LBMConfig` 自动生成，请勿手改。**

-仓库中检入的 `config/*.h` 可能是历史版本。`compiler.generate_config` 会复制 kernel 源码到独立临时构建目录，并在副本中生成配置；不会改写包内头文件或 PTX。返回目录须显式传给 `compile_kernel(build_dir=...)`，编译结果与配置摘要均保存在该目录。`Simulation` 负责目录清理；直接使用编译器的调用者须调用 `cleanup_build_dir()`。跳过生成配置直接编译仓库中的 `uniform.cu` 属不受支持用法。
+仓库中检入的 `config/*.h` 可能是历史版本。`compiler_v2.generate_config` 会复制 kernel 源码到独立临时构建目录，并在副本中生成配置；不会改写包内头文件或 PTX。返回目录须显式传给 `compile_kernel(build_dir=...)`，编译结果与配置摘要均保存在该目录。`Simulation` 负责目录清理；直接使用编译器的调用者须调用 `cleanup_build_dir()`。跳过生成配置直接编译仓库中的 `kernel_v2.cu` 属不受支持用法。

 ```
 config_lbm.json
  ↓  load_lbm_config()
 config.py:LBMConfig       (读取 + 校验)
  ↓  to_macros()
-cuda/compiler.py          (独立构建目录中生成 config/*.h)
+cuda/compiler_v2.py       (独立构建目录中生成 config/*.h)
  ↓
 config_grid.h             → NX, NY, NZ, NT, LATTICE_MODEL；
                            DIM / NQ 由 LATTICE_MODEL 推导写入（与 grid.lattice_model 一致，非 JSON 顶层字段）
@@ -86,20 +86,6 @@ step/one_step_*.cu         → kernel 编排
 - 转速 `omega` 属于运行时状态，可在步进期间更新；该更新不改变 `N_OBJS` 或 `OBS_*` 内存布局，因此**不需要**因 `omega` 变化触发重新编译。
 - 力矩观测从 `obs` 的 torque segment 读取；force / torque / sensor 段统一由 `config_obs.h` 宏描述。

-### 外边界能力（Outer boundaries, dense `Simulation`）
-
-The dense path supports one channel package, not four independently
-selectable sides:
- left x = 0: velocity inlet (`method.inlet.scheme`, `profile`, `physics.velocity`);
- right x = nx−1: outlet (`method.outlet.mode`; `neq_extrap` holds rho = 1 with
-  a `max(u, 0)` backflow clamp when `backflow_clamp` is set);
- bottom and top: one shared `y_wall_bc` (`bounce_back` halfway or
-  `free_slip`); corners are walls.
-`y_wall_bc = "on_site_velocity"` switches to x-periodic with on-site y planes
-and requires an object-free domain. There is no x/y-periodic or symmetry
-option for domains with bodies; adding outer BC types is a separate design
-question, not covered by these keys.
-
 ### 稳定性默认窗口（Stability defaults）

 - 默认 `method.omega_guard = {min: 0.01, max: 1.99}`，用于约束碰撞频率与 LES 有效粘度路径。
@@ -1,4 +1,4 @@
 """CUDA build helpers (compilation itself does not need a live context)."""
-from . import compiler
+from . import compiler_v2 as compiler

 __all__ = ["compiler"]
@@ -1,13 +1,11 @@
-# CelerisLab/cuda/compiler.py
+# CelerisLab/cuda/compiler_v2.py
 """
 Kernel configuration, compilation, and module loading.

-Owners call build_module(cfg, entry, arch=...), then set_params(module, omega, ...).
-build_module runs, in a private directory it removes afterwards:
+Workflow:
  1. build_dir = generate_config(lbm_cfg, n_objects) — isolated source snapshot
-  2. compile_kernel(arch, source=entry, build_dir=build_dir) — nvcc -ptx
+  2. compile_kernel(arch, build_dir=build_dir)       — nvcc -ptx kernel_v2.cu
  3. load_module(ptx_path)              — PyCUDA module from PTX
-Entries: uniform.cu (uniform grid), blocked.cu (every blocked level, single or refined).
 """

 from __future__ import annotations
@@ -18,6 +16,7 @@ import shutil
 import tempfile
 import hashlib
 import json
+from contextvars import ContextVar
 from dataclasses import asdict
 from pathlib import Path
 from typing import Optional
@@ -34,6 +33,9 @@ _KERNEL_DIR = os.path.join(
 )


+_last_build_dir = ContextVar("celeris_last_build_dir", default=None)
+_last_ptx_path = ContextVar("celeris_last_ptx_path", default=None)
+

 def kernel_path(filename: str) -> str:
    return os.path.join(_KERNEL_DIR, filename)
@@ -52,16 +54,14 @@ def _write(path: str, content: str):


 def generate_config(cfg: LBMConfig, n_objects: int = 0,
-                    *, build_root: Optional[str] = None, block_root_bc: int = 0) -> str:
+                    *, build_root: Optional[str] = None) -> str:
    """Snapshot kernels and render headers in a fresh private directory.

-    Returns its path; pass it to compile_kernel(build_dir=...). The caller owns cleanup_build_dir() once the loaded module is no longer
+    Returns its path. Pass it explicitly to compile_kernel for interleaved
+    builds. Legacy generate_config(); compile_kernel() remains context-local.
+    The caller owns cleanup_build_dir() once the loaded module is no longer
    needed for recompilation/debugging. No package files are changed.
-    block_root_bc specializes a blocked root module; fine/dense builds use 0.
    """
-    if (isinstance(block_root_bc, bool) or not isinstance(block_root_bc, int)
-            or block_root_bc not in (0, 1, 2)):
-        raise ValueError("block_root_bc must be an integer mode 0, 1 or 2")
    macros = cfg.to_macros()
    if isinstance(n_objects, bool) or not isinstance(n_objects, int) or n_objects < 0:
        raise ValueError("n_objects must be a nonnegative integer")
@@ -71,19 +71,20 @@ def generate_config(cfg: LBMConfig, n_objects: int = 0,
    try:
        shutil.copytree(_KERNEL_DIR, build_dir, dirs_exist_ok=True,
                        ignore=shutil.ignore_patterns("*.ptx", "*.cubin", "*.tmp"))
-        _render_config(macros, n_objects, os.path.join(build_dir, "config"),
-                       block_root_bc=block_root_bc)
+        _render_config(macros, n_objects, os.path.join(build_dir, "config"))
        digest = hashlib.sha256()
        for path in sorted(Path(build_dir).rglob("*")):
            if path.is_file():
                digest.update(str(path.relative_to(build_dir)).encode())
                digest.update(path.read_bytes())
        metadata = {"source_sha256": digest.hexdigest(), "config": asdict(cfg),
-                    "n_objects": n_objects, "block_root_bc": block_root_bc}
+                    "n_objects": n_objects}
        _write(os.path.join(build_dir, ".celeris-build"), json.dumps(metadata, sort_keys=True))
    except BaseException:
        shutil.rmtree(build_dir)
        raise
+    _last_build_dir.set(build_dir)
+    _last_ptx_path.set(None)
    return build_dir


@@ -95,9 +96,12 @@ def cleanup_build_dir(build_dir: Optional[str]) -> None:
    if path == Path(_KERNEL_DIR).resolve() or not (path / ".celeris-build").is_file():
        raise ValueError("Refusing to remove a directory not owned by the compiler")
    shutil.rmtree(path)
+    if _last_build_dir.get() == str(build_dir):
+        _last_build_dir.set(None)
+        _last_ptx_path.set(None)


-def _render_config(m: dict, n_objects: int, cdir: str, *, block_root_bc: int = 0):
+def _render_config(m: dict, n_objects: int, cdir: str):
    _write(os.path.join(cdir, "config_grid.h"), f"""{_HEADER}\
 // Layer: Global / Grid
 #ifndef CELERIS_CONFIG_GRID_H
@@ -161,9 +165,6 @@ def _render_config(m: dict, n_objects: int, cdir: str, *, block_root_bc: int = 0
 #define STORE_PRECISION  {m['STORE_PRECISION']}
 #define USE_DDF_SHIFTING {m['USE_DDF_SHIFTING']}

-// Internal blocked root mode: 0=periodic/fine, 1=slot/reservoir, 2=channel.
-#define BLOCK_ROOT_BC {block_root_bc}
-
 #define USE_LES {m['USE_LES']}
 #define LES_CS  {m['LES_CS']}
 #define LES_CLOSED_FORM {m['LES_CLOSED_FORM']}
@@ -240,9 +241,13 @@ def _render_config(m: dict, n_objects: int, cdir: str, *, block_root_bc: int = 0
 # ---------------------------------------------------------------------------
 # Compilation
 # ---------------------------------------------------------------------------
-def compile_kernel(arch: str = "sm_70", source: str = "uniform.cu",
-                   output: Optional[str] = None, *, build_dir: str) -> str:
-    """Compile the snapshot in build_dir (from generate_config); never package headers."""
+def compile_kernel(arch: str = "sm_70", source: str = "kernel_v2.cu",
+                   output: Optional[str] = None, *,
+                   build_dir: Optional[str] = None) -> str:
+    """Compile a generated private source snapshot; never use package headers."""
+    # A failed attempt must not make implicit load_module() reuse older code.
+    _last_ptx_path.set(None)
+    build_dir = build_dir or _last_build_dir.get()
    if not build_dir or not (Path(build_dir) / ".celeris-build").is_file():
        raise RuntimeError("Call generate_config() and pass its build_dir before compiling")
    root = Path(build_dir).resolve()
@@ -267,36 +272,23 @@ def compile_kernel(arch: str = "sm_70", source: str = "uniform.cu",
    finally:
        if os.path.exists(tmp):
            os.unlink(tmp)
+    _last_ptx_path.set(str(dst))
    return str(dst)


-def load_module(ptx_path: str):
-    """Load one compiled PTX file as a new PyCUDA module."""
+def load_module(ptx_path: Optional[str] = None):
+    """Load explicit PTX or the last PTX compiled in this Python context."""
+    ptx_path = ptx_path or _last_ptx_path.get()
+    if not ptx_path:
+        raise RuntimeError("No compiled PTX; call compile_kernel() first")
    import pycuda.driver as cuda
    return cuda.module_from_file(ptx_path)


-def build_module(cfg: LBMConfig, source: str, *, arch: str, n_objects: int = 0,
-                 block_root_bc: int = 0):
-    """Generate, compile and load one private module; the build directory is removed.
+# ---------------------------------------------------------------------------
+# Back-compat helpers (used by test scripts)
+# ---------------------------------------------------------------------------

-    The single build path of every owner (Simulation, FixedPatchStepper levels).
-    Each call returns a NEW module: callers must not share it, because its
-    globals (d_params, ...) are mutable per module.
-    """
-    build_dir = generate_config(cfg, n_objects=n_objects, block_root_bc=block_root_bc)
-    try:
-        return load_module(compile_kernel(arch, source=source, build_dir=build_dir))
-    finally:
-        cleanup_build_dir(build_dir)
-
-
-def set_params(module, omega: float, fx: float = 0.0, fy: float = 0.0, fz: float = 0.0,
-               n_objects: int = 0) -> None:
-    """Write the module's __constant__ LBMParams (core/params.cuh layout)."""
-    import struct
-    import pycuda.driver as cuda
-    ptr, size = module.get_global("d_params")
-    if size != struct.calcsize("=ffffI"):
-        raise RuntimeError("LBMParams host/device layout mismatch")
-    cuda.memcpy_htod(ptr, struct.pack("=ffffI", omega, fx, fy, fz, n_objects))
+def compile_kernel_v2(arch: str = "sm_70") -> str:
+    """Alias for compile_kernel() kept for test-script compatibility."""
+    return compile_kernel(arch=arch)
@@ -2,7 +2,7 @@
 """Packed ``obs`` buffer layout for force / torque / sensor telemetry.

 Usage::
-    Host code (e.g. ``ObjectManager``) and ``compiler.generate_config`` must use
+    Host code (e.g. ``ObjectManager``) and ``compiler_v2.generate_config`` must use
    the same ``dim`` and ``n_objects`` so allocation sizes match device macros.

 Design::
@@ -0,0 +1,286 @@
+# CelerisLab/lbm/block_stepper.py
+"""Opt-in periodic backend for one BlockLayout2D level, optional static circles.
+
+D2Q9/SRT/FP32 unforced double buffers. Each step refreshes every halo from
+its owner core, then pulls/collides core cells into the spare buffer, then
+swaps. Only halo pair tables are uploaded; dense ownership stays on the host.
+The caller owns the CudaContext and must close this backend before it.
+Optional ``objects`` are stationary passive circles (static linear BFL via
+receiver-local staging: halo refresh -> cut links -> pull, no copy between).
+No force/actuation readout, motion, walls, refinement, checkpoint or runtime
+parameter mutation; wall/slot/inlet fields in cfg are ignored.
+"""
+from dataclasses import replace
+from numbers import Integral
+import struct
+from threading import RLock
+
+import numpy as np
+import pycuda.driver as cuda
+
+from ..cuda import compiler_v2 as compiler
+from .blocks import NQ, BlockLayout2D, blocked_link_tables
+from .descriptors import D2Q9_EX, D2Q9_EY, FLUID, SOLID
+from .population_storage import _StoredPopulations, _encode_physical, _decode_stored
+
+MAX_GRID_DIM = 65535  # CUDA gridDim.y/z limit (rows, blocks)
+
+
+def _static_circles(layout, objects):
+    """Host tables for stationary circles; rejects before any CUDA work.
+
+    Every periodic neighbor of every fluid core is inspected, including domain
+    edges that CircleGeometry does not enumerate, so clipped or incomplete
+    geometry cannot pass. Each physical link has one receiver-owning block.
+    """
+    from ..body.geometry.circle import CircleGeometry
+
+    ny, nx = layout.shape
+    flags = np.full(ny * nx, FLUID, np.uint16)
+    for obj in objects:
+        if (type(obj.geometry) is not CircleGeometry or obj.is_sensor or obj.is_force_region
+                or obj.surface_actuation is not None
+                or any(getattr(obj.state, name) != 0 for name in ("vx", "vy", "omega"))
+                or any(vars(obj.control).values())):
+            raise ValueError("Block bodies must be stationary passive circles")
+        cx, cy = obj.geometry.center
+        radius = obj.geometry._radius
+        if not np.isfinite([cx, cy, radius]).all() or radius <= 0:
+            raise ValueError("Block circle center/radius must be finite with radius > 0")
+        mask = obj.geometry.build_flag_mask(nx, ny)
+        solid = (mask & SOLID) != 0
+        if not solid.any() or np.any(flags[solid] & SOLID):
+            raise ValueError("Block circles must be resolved and disjoint")
+        flags[solid] = mask[solid]
+    solid = ((flags & SOLID) != 0).reshape(ny, nx)
+    if solid[[0, -1]].any() or solid[:, [0, -1]].any():
+        raise ValueError("Block circles must not touch the domain edge")
+    links = [link for obj in objects
+             for link in obj.geometry.build_cut_links(nx, ny, domain_flags=flags)]
+    def source(r, q):
+        y, x = divmod(r, nx)
+        return (y + D2Q9_EY[q]) % ny, (x + D2Q9_EX[q]) % nx
+    receivers = {(int(link.fluid_idx), int(link.dir)) for link in links}
+    required = {(int(r), q) for r in np.flatnonzero(~solid.ravel())
+                for q in range(1, NQ) if solid[source(r, q)]}
+    if len(receivers) != len(links) or receivers != required:
+        raise ValueError("Cut links must cover every fluid pull from a solid exactly once")
+    tables, _ = blocked_link_tables(
+        layout, flags, np.array([link.fluid_idx for link in links], np.uint32),
+        np.array([link.dir for link in links], np.uint8),
+        np.array([link.q for link in links], np.float32),
+        np.array([link.fallback for link in links], np.uint8))
+    return dict(solid=solid, **tables)
+
+
+class PeriodicBlockStepper:
+    """G->G stepping of Q-major (9, ny, nx) postcollision populations.
+
+    On a device/launch failure the instance becomes unusable: close and
+    recreate it rather than assuming a partially advanced buffer rolled back.
+    """
+    def __init__(self, cfg, layout, *, context, objects=()):
+        if not isinstance(layout, BlockLayout2D) or layout.periodic != (True, True):
+            raise ValueError("PeriodicBlockStepper requires a doubly periodic BlockLayout2D")
+        checked = replace(cfg)
+        checked.validate()
+        if (not checked.is_d2q9 or checked.collision != "SRT"
+                or checked.streaming != "double_buffer" or checked.store_precision != "FP32"
+                or checked.les_enabled
+                or (checked.ny, checked.nx) != layout.shape):
+            raise ValueError("PeriodicBlockStepper requires matching D2Q9/SRT/FP32/"
+                             "double_buffer config without LES")
+        ly, lx = layout.local_shape
+        pairs = len(layout.halo_dst)
+        tpb = checked.threads_per_block
+        if layout.nblocks > MAX_GRID_DIM or ly > MAX_GRID_DIM or not 0 < pairs < 2**31:
+            raise ValueError("block count, block rows or halo pairs exceed launch limits")
+        objects = tuple(objects)  # an empty iterable takes the body-free path
+        self.boundary = _static_circles(layout, objects) if objects else None
+        links = 0 if self.boundary is None else len(self.boundary["cell"])
+        if links >= 2**31:
+            raise ValueError("cut links exceed launch limits")
+        self._ddf_shifting = bool(checked.ddf_shifting)
+        self.layout = layout
+        self.ctx = context
+        self._links = links
+        self._link_grid = ((links + tpb - 1) // tpb, 1)
+        # Wall/slot fields are not applied; neutralize them like the fine patch level.
+        self._local_cfg = replace(checked, nx=lx, ny=ly, y_wall_bc="bounce_back", top_wall_bc="velocity",
+                                  wall_slot_width=0, wall_normal_velocity=0.0, velocity=0.0)
+        self._block = (tpb, 1, 1)
+        self._grid = ((lx + tpb - 1) // tpb, ly, layout.nblocks)
+        self._copy_grid = ((pairs + tpb - 1) // tpb, 1)
+        self._bytes = int(np.prod(layout.blocked_shape)) * 4
+        self._lock = RLock()
+        self._status = "new"
+        self._step_count = 0
+        self._allocations = []
+        self._stream = self._module = self._copy = self._step = self._curved = None
+        self._tables = {}
+        with self.ctx.activate():
+            try:
+                free, _ = cuda.mem_get_info()
+                tables = sum(a.nbytes for k, a in (self.boundary or {}).items() if k != "solid")
+                if 2 * self._bytes + layout.halo_dst.nbytes + layout.halo_src.nbytes + tables > free:
+                    raise MemoryError("blocked buffers exceed free device memory")
+                self._stream = cuda.Stream()
+                config = self._local_cfg
+                config.validate()
+                if not np.isclose(config.omega, 1 / (3 * checked.viscosity + .5), rtol=1e-14, atol=0):
+                    raise RuntimeError("block omega/tau mismatch")
+                build = compiler.generate_config(config)
+                try:
+                    ptx = compiler.compile_kernel(self.ctx.sm_arch, source="blocks.cu", build_dir=build)
+                    module = compiler.load_module(ptx)
+                finally:
+                    compiler.cleanup_build_dir(build)
+                ptr, size = module.get_global("d_params")
+                if size != struct.calcsize("=ffffI"):
+                    raise RuntimeError("LBMParams host/device layout mismatch")
+                cuda.memcpy_htod(ptr, struct.pack("=ffffI", config.omega, 0, 0, 0, 0))
+                self._module = module
+                self._current = self._allocate(self._bytes)
+                self._spare = self._allocate(self._bytes)
+                self._dst = self._upload(layout.halo_dst)
+                self._src = self._upload(layout.halo_src)
+                self._copy = module.get_function("BlockHaloCopy")
+                self._step = module.get_function("BlockStep")
+                if self.boundary is not None:
+                    self._tables = {k: self._upload(a) for k, a in self.boundary.items() if k != "solid"}
+                    self._curved = module.get_function("BlockCurvedBoundary")
+            except BaseException:
+                try:
+                    self.close()
+                except Exception:
+                    pass  # Preserve the original construction failure.
+                raise
+
+    def _allocate(self, size):
+        pointer = cuda.mem_alloc(size)
+        self._allocations.append(pointer)
+        return pointer
+
+    def _upload(self, array):
+        array = np.ascontiguousarray(array)
+        pointer = self._allocate(array.nbytes)
+        cuda.memcpy_htod(pointer, array)
+        return pointer
+
+    def _require(self, *states):
+        if self._status not in states:
+            raise RuntimeError(f"Block stepper is {self._status}; expected {' or '.join(states)}")
+
+    @property
+    def step_count(self):
+        return self._step_count
+
+    def initialize(self, g):
+        """Upload dense G_0; the spare buffer starts NaN so stale halos cannot hide."""
+        with self._lock, self.ctx.activate():
+            self._require("new", "ready")
+            dense = np.array(g, dtype=np.float64 if self._ddf_shifting else np.float32,
+                             order="C", copy=True)
+            if dense.shape != (NQ, *self.layout.shape):
+                raise ValueError("Expected a Q-major (9, ny, nx) array")
+            fluid = np.ones(self.layout.shape, bool) if self.boundary is None else ~self.boundary["solid"]
+            if not np.isfinite(dense[:, fluid]).all() or (dense[:, fluid].sum(axis=0) <= 0).any():
+                raise ValueError("Fluid populations must be finite with positive density")
+            dense[:, ~fluid] = np.nan  # Solid cores are deliberately invalid.
+            encoded = _encode_physical(dense, self._ddf_shifting)
+            values = encoded[:, fluid]
+            if (not np.isfinite(values).all()
+                    or (values.sum(axis=0, dtype=np.float64) + int(self._ddf_shifting) <= 0).any()):
+                raise ValueError("Stored fluid populations must be finite with positive density")
+            blocked = self.layout.to_blocked(encoded)
+            spare = np.full_like(blocked, np.nan)
+            try:
+                cuda.memcpy_htod(self._current, blocked)
+                cuda.memcpy_htod(self._spare, spare)
+                self._step_count = 0
+                self._status = "ready"
+            except BaseException:
+                self._status = "failed"
+                raise
+
+    def step(self, n=1):
+        """Advance n steps: halo refresh, then core pull/collide, per step."""
+        if isinstance(n, bool) or not isinstance(n, Integral) or n < 0:
+            raise ValueError("n must be a nonnegative integer")
+        with self._lock, self.ctx.activate():
+            self._require("ready")
+            kw = dict(block=self._block, stream=self._stream)
+            try:
+                self._status = "advancing"
+                for _ in range(n):
+                    self._copy(self._current, self._dst, self._src,
+                               np.uint32(len(self.layout.halo_dst)), grid=self._copy_grid, **kw)
+                    if self._curved is not None:
+                        t = self._tables
+                        self._curved(self._current, t["block"], t["cell"], t["dir"], t["q"],
+                                     t["fallback"], np.uint32(self._links), np.uintp(0),  # no actuation
+                                     np.uintp(0), np.uintp(0), np.uintp(0),  # no observation
+                                     grid=self._link_grid, **kw)
+                    self._step(self._current, self._spare, np.uint32(self.layout.halo),
+                               self._tables.get("flags", np.uintp(0)), np.uintp(0),  # no kind
+                               grid=self._grid, **kw)
+                    self._stream.synchronize()
+                    self._current, self._spare = self._spare, self._current
+                    self._step_count += 1
+                self._status = "ready"
+            except BaseException:
+                self._status = "failed"
+                raise
+
+    def download(self):
+        """Return physical core populations (FP64 when shifted); no host cache."""
+        snapshot = self._download_raw()
+        return _decode_stored(snapshot.values[0], snapshot.shifted)
+
+    def _download_raw(self):
+        """Return one tagged dense FP32 population array without conversion."""
+        with self._lock, self.ctx.activate():
+            self._require("ready")
+            blocked = np.empty(self.layout.blocked_shape, np.float32)
+            try:
+                cuda.memcpy_dtoh(blocked, self._current)
+            except BaseException:
+                self._status = "failed"
+                raise
+            return _StoredPopulations((self.layout.to_dense(blocked),), self._ddf_shifting)
+
+    def close(self):
+        """Release owned resources; retain them for retry if context activation fails."""
+        with self._lock:
+            if self._status == "closed":
+                return
+            self._status = "failed"
+            with self.ctx.activate():
+                self._status = "closed"
+                error = None
+                try:
+                    if self._stream is not None:
+                        self._stream.synchronize()
+                except Exception as exc:
+                    error = exc
+                self._copy = self._step = self._curved = self._module = None
+                self._tables = {}
+                for pointer in self._allocations:
+                    try:
+                        pointer.free()
+                    except Exception as exc:
+                        error = error or exc
+                self._allocations.clear()
+                self._stream = None
+                if error is not None:
+                    raise error
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *exc):
+        try:
+            self.close()
+        except Exception:
+            if exc[0] is None:
+                raise
@@ -18,9 +18,7 @@ all NQ populations from an owner core cell into another block's halo cell.
 Periodicity is explicit per axis. Across a non-periodic exterior, halo cells
 have no pair and stay invalid (NaN after packing): no wrap, no implied BC.

-Host preparation plus thin launch wrappers: no CUDA import or allocation
-(launch_* only call kernels and device tables the caller owns), no refinement
-levels; level_config and static_circle_tables prepare one blocked level.
+Preparation only: no CUDA, no boundary conditions, no refinement levels.
 The one-cell same-level halo here is unrelated to the four-cell fine halo of
 the fixed refinement patch (refinement.py), whose semantics are unchanged.

@@ -33,7 +31,7 @@ receiver-local boundary values: the solid's owner-core copy of that slot may
 be stale, which is distinct from the unique core ownership of stored state.
 No moving geometry is implied.
 """
-from dataclasses import dataclass, replace
+from dataclasses import dataclass
 from numbers import Integral
 from types import SimpleNamespace

@@ -375,84 +373,3 @@ def blocked_link_tables(layout, flags, fluid_idx, dir, q, fallback):
                  dir=columns[1].astype(np.uint8), q=columns[2].astype(np.float32),
                  fallback=columns[3].astype(np.uint8))
    return tables, mapped
-
-
-# One blocked level as FixedPatchStepper builds and launches it (any depth). Raw argument orders of the blocked.cu kernels live only here.
-
-def level_config(cfg, layout, tau):
-    """Kernel config of one blocked level: NX/NY = block window incl. halo.
-
-    Physical wall/slot/inlet fields are neutralized; a blocked root gets them
-    from its module globals (d_block_wall/d_block_channel) instead.
-    """
-    ly, lx = layout.local_shape
-    local = replace(cfg, nx=lx, ny=ly, y_wall_bc="bounce_back", top_wall_bc="velocity",
-                    wall_slot_width=0, wall_normal_velocity=0.0, velocity=0.0)
-    local.validate()
-    if not np.isclose(local.omega, 1 / tau, rtol=1e-14, atol=0):
-        raise RuntimeError("block level omega/tau mismatch")
-    return local
-
-
-def launch_halo_copy(kernel, buffer, dst, src, count, *, block, stream):
-    """BlockHaloCopy over ``count`` uploaded (dst, src) block-cell pairs."""
-    kernel(buffer, dst, src, np.uint32(count),
-           grid=((count + block[0] - 1) // block[0], 1), block=block, stream=stream)
-
-
-def launch_curved_boundary(kernel, buffer, tables, count, *, block, stream,
-                           velocity=None, rx=None, ry=None, raw=None):
-    """BlockCurvedBoundary on uploaded link tables; None = no actuation/observation."""
-    none = np.uintp(0)
-    kernel(buffer, tables["block"], tables["cell"], tables["dir"], tables["q"], tables["fallback"],
-           np.uint32(count), none if velocity is None else velocity,
-           none if rx is None else rx, none if ry is None else ry, none if raw is None else raw,
-           grid=((count + block[0] - 1) // block[0], 1), block=block, stream=stream)
-
-
-def static_circle_tables(layout, objects):
-    """Host tables for stationary circles; rejects before any CUDA work.
-
-    Every periodic neighbor of every fluid core is inspected, including domain
-    edges that CircleGeometry does not enumerate, so clipped or incomplete
-    geometry cannot pass. Each physical link has one receiver-owning block.
-    """
-    from ..body.geometry.circle import CircleGeometry
-    from .descriptors import FLUID, SOLID
-
-    ny, nx = layout.shape
-    flags = np.full(ny * nx, FLUID, np.uint16)
-    for obj in objects:
-        if (type(obj.geometry) is not CircleGeometry or obj.is_sensor or obj.is_force_region
-                or obj.surface_actuation is not None
-                or any(getattr(obj.state, name) != 0 for name in ("vx", "vy", "omega"))
-                or any(vars(obj.control).values())):
-            raise ValueError("Block bodies must be stationary passive circles")
-        cx, cy = obj.geometry.center
-        radius = obj.geometry._radius
-        if not np.isfinite([cx, cy, radius]).all() or radius <= 0:
-            raise ValueError("Block circle center/radius must be finite with radius > 0")
-        mask = obj.geometry.build_flag_mask(nx, ny)
-        solid = (mask & SOLID) != 0
-        if not solid.any() or np.any(flags[solid] & SOLID):
-            raise ValueError("Block circles must be resolved and disjoint")
-        flags[solid] = mask[solid]
-    solid = ((flags & SOLID) != 0).reshape(ny, nx)
-    if solid[[0, -1]].any() or solid[:, [0, -1]].any():
-        raise ValueError("Block circles must not touch the domain edge")
-    links = [link for obj in objects
-             for link in obj.geometry.build_cut_links(nx, ny, domain_flags=flags)]
-    def source(r, q):
-        y, x = divmod(r, nx)
-        return (y + D2Q9_EY[q]) % ny, (x + D2Q9_EX[q]) % nx
-    receivers = {(int(link.fluid_idx), int(link.dir)) for link in links}
-    required = {(int(r), q) for r in np.flatnonzero(~solid.ravel())
-                for q in range(1, NQ) if solid[source(r, q)]}
-    if len(receivers) != len(links) or receivers != required:
-        raise ValueError("Cut links must cover every fluid pull from a solid exactly once")
-    tables, _ = blocked_link_tables(
-        layout, flags, np.array([link.fluid_idx for link in links], np.uint32),
-        np.array([link.dir for link in links], np.uint8),
-        np.array([link.q for link in links], np.float32),
-        np.array([link.fallback for link in links], np.uint8))
-    return dict(solid=solid, **tables)
@@ -94,10 +94,12 @@ class CurvedLinkSoA:
        """
        self.surface_velocity = self.aperture = None
        self.jets, self.jet_shape, self.jet_id = tuple(jets), None, None
-        from ..body.jets import _surface_links
-        self.surface_velocity, self.aperture, self.jet_shape, self.jet_id = _surface_links(
+        self.surface_velocity, self.aperture = surface_link_velocity(
            objects, cfg, flags, self.fluid_idx, self.dir, self.body_id, self.rx, self.ry,
            jets=self.jets, hits=hits)
+        if self.jets:
+            from ..body.jets import jet_link_shapes
+            self.jet_shape, self.jet_id = jet_link_shapes(self.jets, hits)

    def set_jet_amplitude(self, index, amplitude, stream=None):
        """Rewrite jet rows from cached shapes; re-upload only the velocity column.
@@ -21,24 +21,7 @@ from .refinement import (ACTIVE, OUTER_GHOST, FixedPatch2D, FixedPatchSet2D,
@dataclass(frozen=True, eq=False)
 class Hierarchy:
    """configs[l]: validated LBMConfig of level l; pairs[l]: tables of (l, l+1);
-    kinds[l]: composed per-cell kind (child coverage OUTER on every non-finest level).
-
-    Index conventions (the single place they are defined):
-      * level l = 0 (root) .. depth-1; pair index p = l-1 builds level l from level p;
-      * array shapes are (ny, nx); rectangles, origins and centers are (x, y);
-      * a pair's two members are its COARSE (parent) and FINE (child) level, for every
-        pair, not absolute L0/L1 (fine_shape, fine_origin, blocked_coarse_tables, ...);
-      * refined levels (l >= 1) of FixedPatchStepper place bodies and Jets in the root
-        EDGE frame: root cell i covers [i, i+1), center i+.5. Uniform Simulation objects
-        and the static circles of a single-level (depth 1) FixedPatchStepper use the
-        integer-NODE frame (CircleGeometry.build_flag_mask at integer (x, y)). No
-        NODE<->EDGE input conversion is applied anywhere; inside the EDGE frame, refined
-        boundaries still project root-edge coordinates to fine-local cell indices with
-        the half-cell shift ((v - o)/h - .5, see prepare_fine_boundary);
-      * cell (i, j) of level l's allocated array (ghost band and holes included) covers
-        [o + h*i, o + h*(i+1)) with (o, h) = edge_frame(l); level 1 is built from the root
-        config directly, deeper levels from their parent frame (see edge_frame).
-    """
+    kinds[l]: composed per-cell kind (child coverage OUTER on every non-finest level)."""
    configs: tuple
    pairs: tuple
    kinds: tuple
@@ -47,18 +30,6 @@ class Hierarchy:
    def depth(self):
        return len(self.kinds)

-    def edge_frame(self, level):
-        """(origin (x, y), spacing) of level ``level``'s array in the root edge frame.
-
-        Each pair's fine_origin is in parent cells: zero for a set (level-wide grid),
-        the shifted window origin for a scalar FixedPatch2D.
-        """
-        origin, spacing = (0.0, 0.0), 1.0
-        for pair in self.pairs[:level]:
-            origin = tuple(o + spacing * f for o, f in zip(origin, pair.fine_origin))
-            spacing /= 2
-        return origin, spacing
-

 def is_rectangle(value):
    value = tuple(value)
@@ -115,14 +86,14 @@ def _check_chain(coarse, fine, pair):
 def leaf_partition(h):
    """Base-cell fraction published as ACTIVE over all levels (exact: powers of two).

-    Window (scalar) levels are offset by their fine_level_offset first.
+    Window (scalar) levels are offset by their fine_level_origin first.
    """
    base = np.zeros(h.kinds[0].shape)
    oy = ox = 0
    for level, kind in enumerate(h.kinds):
        if level:
            pair = h.pairs[level - 1]
-            py, px = pair.fine_level_offset
+            py, px = (pair.fine_level_origin if isinstance(pair, FixedPatch2D) else (0, 0))
            oy, ox = 2 * oy + py, 2 * ox + px
        y, x = np.nonzero(kind == ACTIVE)
        np.add.at(base, ((y + oy) >> level, (x + ox) >> level), 0.25 ** level)
@@ -1,47 +0,0 @@
-// CelerisLab/lbm/kernels/blocked.cu
-// One fixed-size blocked level (lbm/blocks.py layout), specialized at compile
-// time for periodic/fine, slot/reservoir or channel stepping. Separate
-// compilation entry: NX, NY are the block window including halo, so index_f
-// and linear_index address one block; blockIdx.z selects the block, whose
-// populations start at b*NQ*TOTAL_CELLS (block-contiguous, Q-major inside).
-#include <stdint.h>
-#include <math.h>
-#include "config.h"
-#include "core/precision.cuh"
-#include "core/descriptors.cuh"
-#include "core/layout.cuh"
-#include "core/params.cuh"
-#include "core/flags.cuh"
-#include "core/obs.cuh"
-#include "core/cell_kind.cuh"
-#include "operators/macro.cuh"
-#include "operators/collision_srt.cuh"
-#if COLLISION_MODEL == 2
-#include "operators/collision_mrt.cuh"
-#endif
-#include "streaming/pull_double_buffer.cuh"
-#include "boundary/curved_boundary.cuh"
-
-#if DIM != 2 || NQ != 9 || (COLLISION_MODEL != 0 && COLLISION_MODEL != 2) || STORE_PRECISION != 0 || USE_LES || STREAMING_MODEL != 0
-#error "Blocks require FP32 D2Q9 SRT or MRT double buffers without LES"
-#endif
-#ifndef BLOCK_ROOT_BC
-#error "Blocks require a generated BLOCK_ROOT_BC mode"
-#elif BLOCK_ROOT_BC < 0 || BLOCK_ROOT_BC > 2
-#error "BLOCK_ROOT_BC must be 0, 1 or 2"
-#endif
-
-#if BLOCK_ROOT_BC == 1
-#include "boundary/block_wall.cuh"
-#endif
-#include "operators/block_collision.cuh"
-
-// Kernels, in definition order: transfers, boundary staging, then the one full
-// step selected for this module (BlockStep, or BlockChannelStep for a channel root).
-#include "step/block_transfer.cu"
-#include "step/block_boundary.cu"
-#if BLOCK_ROOT_BC != 2
-#include "step/block_step.cu"
-#else
-#include "step/block_channel.cu"
-#endif
@@ -0,0 +1,206 @@
+// CelerisLab/lbm/kernels/blocks.cu
+// One periodic level of fixed-size blocks (lbm/blocks.py layout). Separate
+// compilation entry: NX, NY are the block window including halo, so index_f
+// and linear_index address one block; blockIdx.z selects the block, whose
+// populations start at b*NQ*TOTAL_CELLS (block-contiguous, Q-major inside).
+#include <stdint.h>
+#include <math.h>
+#include "config.h"
+#include "core/precision.cuh"
+#include "core/descriptors.cuh"
+#include "core/layout.cuh"
+#include "core/params.cuh"
+#include "core/flags.cuh"
+#include "core/obs.cuh"
+#include "operators/macro.cuh"
+#include "operators/collision_srt.cuh"
+#if COLLISION_MODEL == 2
+#include "operators/collision_mrt.cuh"
+#endif
+#include "streaming/pull_double_buffer.cuh"
+#include "boundary/curved_boundary.cuh"
+#include "boundary/planar_velocity.cuh"
+
+#if DIM != 2 || NQ != 9 || (COLLISION_MODEL != 0 && COLLISION_MODEL != 2) || STORE_PRECISION != 0 || USE_LES || STREAMING_MODEL != 0
+#error "Blocks require FP32 D2Q9 SRT or MRT double buffers without LES"
+#endif
+
+// Fixed-patch cell kinds, matching refinement.py ACTIVE/INNER_GHOST/OUTER_GHOST.
+constexpr unsigned char KIND_ACTIVE = 0u, KIND_INNER = 1u, KIND_OUTER = 2u;
+
+// Zero-initialized for ordinary blocks/fine levels. Set only for parent walls;
+// NX/NY remain local storage strides, never physical wall coordinates.
+struct BlockWall { unsigned int nx, ny, slot_width; float amplitude; };
+extern "C" { __constant__ BlockWall d_block_wall; }
+
+// Halo refresh: block cell ids b*TOTAL_CELLS+c, sources are always core cells.
+extern "C" __global__ void BlockHaloCopy(
+    fpxx* f, const uint64_t* dst, const uint64_t* src, unsigned int count)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    const uint64_t d = dst[row], s = src[row];
+    fpxx* to = f + (d / TOTAL_CELLS) * NQ * TOTAL_CELLS;
+    const fpxx* from = f + (s / TOTAL_CELLS) * NQ * TOTAL_CELLS;
+    for (unsigned int q = 0; q < NQ; ++q)
+        to[index_f(d % TOTAL_CELLS, q)] = from[index_f(s % TOTAL_CELLS, q)];
+}
+
+// Fixed-patch explosion into blocked fine storage: target = owner block cell
+// id of a patch-ghost cell; donors are parent block cell ids. Dense parent
+// storage is the one-window case with coarse_cells = full domain size.
+extern "C" __global__ void BlockExplode(
+    const fpxx* coarse, fpxx* fine, const uint64_t* target, const uint64_t* donor,
+    unsigned int count, unsigned long coarse_cells)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    const uint64_t t = target[row];
+    fpxx* to = fine + (t / TOTAL_CELLS) * NQ * TOTAL_CELLS;
+    const uint64_t d = donor[row];
+    const fpxx* from = coarse + (d / coarse_cells) * NQ * coarse_cells;
+    for (unsigned int q = 0; q < NQ; ++q)
+        to[index_f(t % TOTAL_CELLS, q)] = from[q * coarse_cells + d % coarse_cells];
+}
+
+// Experimental Schornbaum--Ruede (arXiv:1508.07982, Algorithm 2)
+// and Chen et al. (doi:10.1016/j.physa.2005.09.036) population interpolation.
+// Independent implementation of the mathematical stencil; no upstream source copied.
+// Stencil cells are owner cores; a disabled axis repeats its center twice.
+extern "C" __global__ void BlockExplodeProjected(
+    const fpxx* coarse, fpxx* fine, const uint64_t* target, const uint64_t* donor,
+    unsigned int count, unsigned long coarse_cells,
+    const uint64_t* neighbors, const float* offsets)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    const uint64_t t = target[row], d = donor[row];
+    fpxx* to = fine + (t / TOTAL_CELLS) * NQ * TOTAL_CELLS;
+    for (unsigned int q = 0; q < NQ; ++q) {
+        float v[4];
+        for (unsigned int a = 0; a < 4; ++a) {
+            const uint64_t n = neighbors[4ul * row + a];
+            v[a] = coarse[(n / coarse_cells) * NQ * coarse_cells
+                          + q * coarse_cells + n % coarse_cells];
+        }
+        float gx = .5f * (v[1] - v[0]), gy = .5f * (v[3] - v[2]);
+        const float ex = d_cx[q], ey = d_cy[q];
+        if (q != 0) {
+            const float along = (ex * gx + ey * gy) / (ex * ex + ey * ey);
+            gx -= ex * along;
+            gy -= ey * along;
+        }
+        to[index_f(t % TOTAL_CELLS, q)] =
+            coarse[(d / coarse_cells) * NQ * coarse_cells + q * coarse_cells + d % coarse_cells]
+            + offsets[2ul * row] * gx + offsets[2ul * row + 1] * gy;
+    }
+}
+
+// Targets are receiver-local SOURCE slots for the immediately following pull.
+// Keep child summation order identical to PatchCoarseStep; no collision here.
+extern "C" __global__ void BlockCoalesce(
+    const fpxx* fine, fpxx* coarse, const uint64_t* target, const uint64_t* children,
+    unsigned int count)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    const uint64_t* s = children + 4ul * row;
+    coarse[target[row]] = 0.25f * (fine[s[0]] + fine[s[1]] + fine[s[2]] + fine[s[3]]);
+}
+
+// Static cut links, receiver-local staging: cell is the receiver's local core
+// cell, so the existing BFL writes the solid-source window image that this
+// block's next pull reads (no halo copy between this kernel and BlockStep).
+// surface_velocity (nullable, 2 floats per link): prescribed fluid velocity on
+// fixed geometry, same convention as CurvedBoundaryKernel. Optional raw rows
+// (jx,jy,torque,dm) are unique physical links, never body-observation slots.
+extern "C" __global__ void BlockCurvedBoundary(
+    fpxx* f, const uint32_t* block, const uint32_t* cell, const unsigned char* dir,
+    const float* q, const unsigned char* fallback, unsigned int count,
+    const float* surface_velocity, const float* rx, const float* ry, float* raw)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    float Uw = 0.0f, Vw = 0.0f;
+    if (surface_velocity != nullptr) {
+        const float u = surface_velocity[2 * row], v = surface_velocity[2 * row + 1];
+        if (u != 0.0f || v != 0.0f) { Uw = u; Vw = v; }
+    }
+    apply_bouzidi_link(dir[row], q[row], cell[row], f + (unsigned long)block[row] * NQ * TOTAL_CELLS,
+                       Uw, Vw, rx ? rx[row] : 0.0f, ry ? ry[row] : 0.0f,
+                       fallback[row], nullptr, -1, raw ? raw + 4ul * row : nullptr,
+                       raw ? raw + 4ul * row + 3 : nullptr);
+}
+
+// Same-stream BFL -> this row-owned accumulation -> pull step. No atomics,
+// no cross-row reduction and no history allocation proportional to substeps.
+extern "C" __global__ void BlockAccumulateExchange(
+    const float* raw, double* integral, unsigned int count, double h, double dt)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    const unsigned long k = 4ul * row;
+    const double impulse = h * dt;
+    integral[k] += impulse * (double)raw[k];
+    integral[k + 1] += impulse * (double)raw[k + 1];
+    integral[k + 2] += h * impulse * (double)raw[k + 2];
+    integral[k + 3] += h * h * (double)raw[k + 3];
+}
+
+// Pull/collide/store core cells only; halo cells of out are left untouched.
+// flags (block cell ids, nullable): solid cores store NaN and never collide.
+// kind (block cell ids, nullable = all ACTIVE): OUTER skips the pull and
+// stores NaN, INNER pulls without collision, ACTIVE pulls and collides.
+extern "C" __global__ void BlockStep(const fpxx* in, fpxx* out, unsigned int halo,
+                                     const uint16_t* flags, const unsigned char* kind) {
+    unsigned int x, y; unsigned long k;
+    index_from_thread(x, y, k);
+    if (x < halo || y < halo || x >= NX - halo || y >= NY - halo) return;
+    const unsigned long base = (unsigned long)blockIdx.z * NQ * TOTAL_CELLS;
+    const unsigned long cell = (unsigned long)blockIdx.z * TOTAL_CELLS + k;
+    const unsigned char cell_kind = kind != nullptr ? kind[cell] : KIND_ACTIVE;
+    float f[NQ];
+    if (cell_kind == KIND_OUTER || (flags != nullptr && is_solid(flags[cell]))) {
+        for (int q = 0; q < NQ; ++q) f[q] = NAN;
+    } else {
+        unsigned long j[NQ];
+        compute_neighbors(x, y, j);  // Core neighbors stay inside the window: no wrap.
+        stream_pull_load(k, f, in + base, j);
+        if (cell_kind == KIND_ACTIVE) {
+            if (d_block_wall.nx != 0) {
+                const unsigned int bx = NX - 2 * halo, by = NY - 2 * halo;
+                const unsigned int nbx = d_block_wall.nx / bx;
+                const unsigned int gx = (blockIdx.z % nbx) * bx + x - halo;
+                const unsigned int gy = (blockIdx.z / nbx) * by + y - halo;
+                if (gy == 1)
+                    reconstruct_bottom_velocity(f, 0.0f, bottom_wall_normal_velocity(
+                        gx, d_block_wall.nx, d_block_wall.slot_width, d_block_wall.amplitude));
+                else if (gy == d_block_wall.ny - 2) reconstruct_top_reservoir(f, RHO);
+            }
+#if COLLISION_MODEL == 2
+            // Uniform MRT sequence (collide_dispatch, zero forcing); SRT path below unchanged.
+            float rho, ux, uy;
+            compute_rho_u(f, rho, ux, uy);
+            collide_mrt_no_force(f, rho, ux, uy,
+                fminf(OMEGA_COLLISION_MAX, fmaxf(OMEGA_COLLISION_MIN, d_params.omega)));
+#else
+            float rho, ux, uy, feq[NQ];
+            compute_rho_u(f, rho, ux, uy);
+#if USE_DDF_SHIFTING
+            // Preserve the density perturbation before adding the unit reference.
+            const float drho = f[0]+f[1]+f[2]+f[3]+f[4]+f[5]+f[6]+f[7]+f[8];
+            const float jx = f[1]-f[2]+f[5]-f[6]+f[7]-f[8];
+            const float jy = f[3]-f[4]+f[5]-f[6]-f[7]+f[8];
+            compute_feq_from_momentum(drho, jx, jy, ux, uy, feq);
+#else
+            compute_feq(rho, ux, uy, feq);
+#endif
+            collide_srt_no_force(f, feq, d_params.omega);
+#endif
+        }
+    }
+    stream_pull_store(k, f, out + base);
+}
+
+// Root channel closure; fine and periodic levels keep BlockStep.
+#include "step/block_channel.cu"
@@ -1,20 +0,0 @@
-// Physical parent walls; NX/NY remain local storage strides.
-#ifndef CELERIS_BOUNDARY_BLOCK_WALL_CUH
-#define CELERIS_BOUNDARY_BLOCK_WALL_CUH
-
-#include "planar_velocity.cuh"
-
-struct BlockWall { unsigned int nx, ny, slot_width; float amplitude; };
-extern "C" { __constant__ BlockWall d_block_wall; }
-
-__device__ __forceinline__ void block_wall(float* f, unsigned int x, unsigned int y,
-                                         unsigned int halo) {
-    unsigned int gx, gy;
-    block_global_xy(x, y, halo, d_block_wall.nx, gx, gy);
-    if (gy == 1)
-        reconstruct_bottom_velocity(f, 0.0f, bottom_wall_normal_velocity(
-            gx, d_block_wall.nx, d_block_wall.slot_width, d_block_wall.amplitude));
-    else if (gy == d_block_wall.ny - 2) reconstruct_top_reservoir(f, RHO);
-}
-
-#endif
@@ -15,13 +15,10 @@
 // D2Q9 y-wall half-way bounce-back for pull double-buffer streaming.
 // ---------------------------------------------------------------------------
 #if LATTICE_MODEL == LATTICE_D2Q9
-// Rows 1 and top_row (= physical ny - 2) next to walls at rows 0 and ny - 1.
-// y is the physical row; k addresses the node in fi_in (a block window may
-// have NX/NY strides different from the physical extent).
-__device__ inline void apply_wall_bb_d2q9_rows(unsigned int y, unsigned int top_row,
-                                               float* __restrict__ f,
-                                               const fpxx* __restrict__ fi_in,
-                                               unsigned long k)
+__device__ inline void apply_wall_bb_d2q9_y_pull(unsigned int y,
+                                                  float* __restrict__ f,
+                                                  const fpxx* __restrict__ fi_in,
+                                                  unsigned long k)
 {
    if (y == 1) {
        // Directions sourced from y=0 wall in pull step: +y, +x+y, -x+y.
@@ -29,22 +26,14 @@ __device__ inline void apply_wall_bb_d2q9_rows(unsigned int y, unsigned int top_
        f[5] = load_ddf(fi_in, index_f(k, 6u));
        f[8] = load_ddf(fi_in, index_f(k, 7u));
    }
-    else if (y == top_row) {
-        // Directions sourced from the y = ny - 1 wall in pull step: -y, -x-y, +x-y.
+    else if (y == (unsigned int)(NY - 2)) {
+        // Directions sourced from y=NY-1 wall in pull step: -y, -x-y, +x-y.
        f[4] = load_ddf(fi_in, index_f(k, 3u));
        f[6] = load_ddf(fi_in, index_f(k, 5u));
        f[7] = load_ddf(fi_in, index_f(k, 8u));
    }
 }

-__device__ inline void apply_wall_bb_d2q9_y_pull(unsigned int y,
-                                                  float* __restrict__ f,
-                                                  const fpxx* __restrict__ fi_in,
-                                                  unsigned long k)
-{
-    apply_wall_bb_d2q9_rows(y, (unsigned int)(NY - 2), f, fi_in, k);
-}
-
 // ---------------------------------------------------------------------------
 // D2Q9 y-wall free-slip (specular reflection) for pull double-buffer streaming.
 //
@@ -8,9 +8,6 @@
 #define STORE_PRECISION  0
 #define USE_DDF_SHIFTING 0

-// Internal blocked root mode: 0=periodic/fine, 1=slot/reservoir, 2=channel.
-#define BLOCK_ROOT_BC 0
-
 #define USE_LES 0
 #define LES_CS  0.160000f
 #define LES_CLOSED_FORM 1
@@ -1,16 +0,0 @@
-// CelerisLab – core/cell_kind.cuh
-// Fixed-patch cell kinds stored per block cell, matching lbm/refinement.py
-// ACTIVE/INNER_GHOST/OUTER_GHOST: OUTER is invalid (stores NaN, no pull),
-// INNER streams without collision, ACTIVE pulls and collides.
-#ifndef CELERIS_CORE_CELL_KIND_CUH
-#define CELERIS_CORE_CELL_KIND_CUH
-
-constexpr unsigned char KIND_ACTIVE = 0u, KIND_INNER = 1u, KIND_OUTER = 2u;
-
-// NaN populations mark a cell without valid state (OUTER ghost or solid core).
-__device__ __forceinline__ void fill_invalid(float* f)
-{
-    for (int q = 0; q < NQ; ++q) f[q] = NAN;
-}
-
-#endif
@@ -53,18 +53,6 @@ __device__ __forceinline__ void index_from_thread(unsigned int& x,
    k = (unsigned long)y * NX + x;
 }

-// Global cell of window cell (x, y) in block blockIdx.z of a row-major,
-// full-domain block layout domain_nx cells wide. NX/NY are the local strides.
-__device__ __forceinline__ void block_global_xy(unsigned int x, unsigned int y,
-                                                unsigned int halo, unsigned int domain_nx,
-                                                unsigned int& gx, unsigned int& gy)
-{
-    const unsigned int bx = NX - 2 * halo, by = NY - 2 * halo;
-    const unsigned int nbx = domain_nx / bx;
-    gx = (blockIdx.z % nbx) * bx + x - halo;
-    gy = (blockIdx.z / nbx) * by + y - halo;
-}
-
 // ---------------------------------------------------------------------------
 // Neighbor list (periodic BCs via modular arithmetic)
 // ---------------------------------------------------------------------------
@@ -44,4 +44,16 @@ struct RigidBodyControl2D {
    int   control_mode;           // 0=force, 1=velocity, 2=displacement
 };

+// ============================================================================
+// Halo plan (multi-GPU / AMR 预留)
+// ============================================================================
+struct HaloPlan {
+    int       face_id;
+    int       peer_gpu;
+    int       level;
+    size_t    count;
+    int*      send_idx;
+    int*      recv_idx;
+};
+
 #endif // CELERIS_CORE_PARAMS_CUH
@@ -1,4 +1,4 @@
-// CelerisLab – uniform.cu
+// CelerisLab – kernel_v2.cu
 // ============================================================================
 // Compilation entry point (Stage 2 Architecture).
 //
@@ -7,7 +7,7 @@
 //
 // File layout (each <300 lines):
 //   operators/helpers.cuh  — bounce_back_swap, collide_dispatch
-//   step/init_flow.cu      — InitTubeFlow, InitEsoPull
+//   step/init_flow.cu      — InitTubeFlow_v2, InitEsoPull
 //   step/one_step_double.cu — OneStep (pull double-buffer)
 //   step/one_step_esopull.cu — EsoPullStep (single-buffer)
 //   step/aux_kernels.cu    — CurvedBoundaryKernel, SensorKernel
@@ -71,7 +71,6 @@ extern "C"
 #include "step/one_step_double.cu"
 #include "step/one_step_esopull.cu"
 #include "step/aux_kernels.cu"
-#include "step/moving_circle.cu"
 #include "step/esopull_macro.cu"
 #include "step/esopull_sync.cu"

@@ -1,47 +0,0 @@
-// CelerisLab – operators/block_collision.cuh
-// The one collision extension point of the blocked steps (BlockStep, BlockChannelStep).
-// Unforced by construction: FixedPatchStepper supplies no forcing, so no runtime
-// d_params.fx/fy branch is read. Two compile-time arithmetic families:
-//   uniform-equivalent (MRT on every level; SRT on the channel root, BLOCK_ROOT_BC 2):
-//          collide_dispatch arithmetic with zero force and no LES: clamped omega;
-//          SRT keeps the zero Guo forcing term of collide_srt;
-//   level SRT (BLOCK_ROOT_BC 0/1): unclamped omega, no forcing term; shifted storage
-//          builds feq from the retained drho and direct momentum (numerical variant).
-#ifndef CELERIS_OPERATORS_BLOCK_COLLISION_CUH
-#define CELERIS_OPERATORS_BLOCK_COLLISION_CUH
-
-#include "../core/params.cuh"
-#include "macro.cuh"
-#include "collision_srt.cuh"
-#if COLLISION_MODEL == 2
-#include "collision_mrt.cuh"
-#endif
-
-__device__ __forceinline__ void block_collide(float* f) {
-    float rho, ux, uy;
-    compute_rho_u(f, rho, ux, uy);
-#if COLLISION_MODEL == 2 || BLOCK_ROOT_BC == 2
-    const float omega = fminf(OMEGA_COLLISION_MAX, fmaxf(OMEGA_COLLISION_MIN, d_params.omega));
-  #if COLLISION_MODEL == 2
-    collide_mrt_no_force(f, rho, ux, uy, omega);
-  #else
-    float feq[NQ], forcing[NQ] = {};
-    compute_feq(rho, ux, uy, feq);
-    collide_srt(f, feq, forcing, omega);
-  #endif
-#else
-    float feq[NQ];
-#if USE_DDF_SHIFTING
-    // Preserve the density perturbation before adding the unit reference.
-    const float drho = f[0]+f[1]+f[2]+f[3]+f[4]+f[5]+f[6]+f[7]+f[8];
-    const float jx = f[1]-f[2]+f[5]-f[6]+f[7]-f[8];
-    const float jy = f[3]-f[4]+f[5]-f[6]-f[7]+f[8];
-    compute_feq_from_momentum(drho, jx, jy, ux, uy, feq);
-#else
-    compute_feq(rho, ux, uy, feq);
-#endif
-    collide_srt_no_force(f, feq, d_params.omega);
-#endif
-}
-
-#endif
@@ -1,14 +0,0 @@
-// CelerisLab – operators/bounce_back_swap.cuh
-// Full-way bounce-back at a wall node: swap every opposite pair (paired
-// order q, q+1). Needs only NQ; shared by the uniform and blocked steps.
-#ifndef CELERIS_OPERATORS_BOUNCE_BACK_SWAP_CUH
-#define CELERIS_OPERATORS_BOUNCE_BACK_SWAP_CUH
-
-__device__ __forceinline__ void bounce_back_swap(float* f) {
-    #pragma unroll
-    for (int i = 1; i < NQ; i += 2) {
-        float t = f[i]; f[i] = f[i+1]; f[i+1] = t;
-    }
-}
-
-#endif
@@ -57,4 +57,25 @@ __device__ __forceinline__ void collide_trt(float* __restrict__ f,
    }
 }

+__device__ __forceinline__ void collide_trt_no_force(float* __restrict__ f,
+                                                     const float* __restrict__ feq,
+                                                     float omega)
+{
+    const float wp = omega;
+    const float wm = compute_omega_minus(wp);
+
+    f[0] = f[0] - wp * (f[0] - feq[0]);
+
+    #pragma unroll
+    for (int i = 1; i < NQ; i += 2) {
+        const int ib = i + 1;
+        const float fi = f[i], fb = f[ib];
+        const float feqi = feq[i], feqb = feq[ib];
+        const float delta_s = 0.5f * ((fi - feqi) + (fb - feqb));
+        const float delta_a = 0.5f * ((fi - feqi) - (fb - feqb));
+        f[i]  = fi  - wp * delta_s - wm * delta_a;
+        f[ib] = fb  - wp * delta_s + wm * delta_a;
+    }
+}
+
 #endif // CELERIS_OPERATORS_COLLISION_TRT_CUH
@@ -5,7 +5,12 @@
 #ifndef CELERIS_OPERATORS_HELPERS_CUH
 #define CELERIS_OPERATORS_HELPERS_CUH

-#include "bounce_back_swap.cuh"
+__device__ __forceinline__ void bounce_back_swap(float* f) {
+    #pragma unroll
+    for (int i = 1; i < NQ; i += 2) {
+        float t = f[i]; f[i] = f[i+1]; f[i+1] = t;
+    }
+}

 __device__ __forceinline__ void collide_dispatch(
    float* f, float rho_n,
@@ -0,0 +1,130 @@
+// Fixed, unforced internal 2:1 patch. Separate compilation entry;
+// default OneStep/channel kernels are deliberately not included.
+#include <stdint.h>
+#include <math.h>
+#include "config.h"
+#include "core/precision.cuh"
+#include "core/descriptors.cuh"
+#include "core/layout.cuh"
+#include "core/params.cuh"
+#include "core/flags.cuh"
+#include "core/obs.cuh"
+#include "operators/macro.cuh"
+#include "operators/collision_srt.cuh"
+#if COLLISION_MODEL == 2
+#include "operators/collision_mrt.cuh"
+#endif
+#include "streaming/pull_double_buffer.cuh"
+#include "boundary/planar_velocity.cuh"
+#include "boundary/curved_boundary.cuh"
+
+extern "C" {
+#include "step/curved_double.cu"
+}
+
+#if DIM != 2 || NQ != 9 || (COLLISION_MODEL != 0 && COLLISION_MODEL != 2) || STORE_PRECISION != 0 || USE_DDF_SHIFTING || USE_LES || STREAMING_MODEL != 0
+#error "Refinement requires unshifted FP32 D2Q9 SRT or MRT double buffers without LES"
+#endif
+
+// Enabled only in the validation build; no diagnostic arrays in normal builds.
+#ifdef CELERIS_REFINEMENT_AUDIT
+extern "C" {
+__device__ unsigned int collision_counts[TOTAL_CELLS];
+__device__ unsigned int explosion_counts[TOTAL_CELLS];
+__device__ unsigned int incoming_counts[NQ * TOTAL_CELLS];
+}
+#endif
+
+__device__ __forceinline__ void patch_collide(float* f, unsigned long k) {
+#if COLLISION_MODEL == 2
+    float rho, ux, uy;
+    compute_rho_u(f, rho, ux, uy);
+    collide_mrt_no_force(f, rho, ux, uy,
+        fminf(OMEGA_COLLISION_MAX, fmaxf(OMEGA_COLLISION_MIN, d_params.omega)));
+#else
+    float rho, ux, uy, feq[NQ];
+    compute_rho_u(f, rho, ux, uy);
+    compute_feq(rho, ux, uy, feq);
+    collide_srt_no_force(f, feq, d_params.omega);
+#endif
+#ifdef CELERIS_REFINEMENT_AUDIT
+    ++collision_counts[k];
+#endif
+}
+
+extern "C" __global__ void PatchExplode(
+    const float* coarse, float* fine, const uint32_t* targets,
+    const uint32_t* donors, unsigned int count, unsigned long coarse_cells)
+{
+    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
+    if (row >= count) return;
+    for (unsigned int q = 0; q < NQ; ++q)
+        fine[index_f(targets[row], q)] = coarse[q * coarse_cells + donors[row]];
+#ifdef CELERIS_REFINEMENT_AUDIT
+    ++explosion_counts[targets[row]];
+#endif
+}
+
+extern "C" __global__ void PatchFineStep(const float* in, float* out, const uint16_t* flags) {
+    unsigned int x, y; unsigned long k;
+    index_from_thread(x, y, k);
+    if (x >= NX || y >= NY) return;
+    float f[NQ];
+    // Outer halo is invalid after EACH hop, including when reusing the buffer
+    // that held explosion data. Inner halo only streams; it never collides.
+    if (x < 2 || y < 2 || x >= NX - 2 || y >= NY - 2
+            || (flags != nullptr && is_solid(flags[k]))) {
+        for (int q = 0; q < NQ; ++q) f[q] = NAN;
+    } else {
+        unsigned long j[NQ];
+        compute_neighbors(x, y, j);  // These interior targets never wrap.
+        stream_pull_load(k, f, in, j);
+        if (x >= 4 && y >= 4 && x < NX - 4 && y < NY - 4)
+            patch_collide(f, k);
+    }
+    stream_pull_store(k, f, out);
+}
+
+extern "C" __global__ void PatchCoarseStep(
+    const float* in, float* out, const float* fine,
+    const uint64_t* targets, const uint64_t* children, unsigned int count,
+    unsigned int x0, unsigned int y0, unsigned int x1, unsigned int y1,
+    unsigned int wall_aware)
+{
+    unsigned int x, y; unsigned long k;
+    index_from_thread(x, y, k);
+    if (x >= NX || y >= NY) return;
+    // Both buffers were poisoned at initialization; covered cells stay invalid.
+    if (x >= x0 && x < x1 && y >= y0 && y < y1) return;
+    if (wall_aware && (y == 0 || y == NY - 1)) return;
+    unsigned long j[NQ];
+    compute_neighbors(x, y, j);
+    float f[NQ];
+    stream_pull_load(k, f, in, j);
+    if (x >= x0 - 1 && x <= x1 && y >= y0 - 1 && y <= y1) {
+        for (unsigned int q = 1; q < NQ; ++q) {
+            uint64_t slot = index_f(k, q);
+            unsigned int lo = 0, hi = count;
+            while (lo < hi) {
+                unsigned int mid = lo + (hi - lo) / 2;
+                if (targets[mid] < slot) lo = mid + 1;
+                else hi = mid;
+            }
+            if (lo < count && targets[lo] == slot) {
+                const uint64_t* s = children + 4ul * lo;
+                f[q] = 0.25f * (fine[s[0]] + fine[s[1]] + fine[s[2]] + fine[s[3]]);
+#ifdef CELERIS_REFINEMENT_AUDIT
+                ++incoming_counts[slot];
+#endif
+            }
+        }
+    }
+    // Includes the eight grazing-corner links with UNCOVERED coarse donors.
+    // All replacement arrivals must be in place before computing rho/u.
+    if (wall_aware) {
+        if (y == 1) reconstruct_bottom_velocity(f, 0.0f, bottom_wall_normal_velocity(x));
+        else if (y == NY - 2) reconstruct_top_reservoir(f, RHO);
+    }
+    patch_collide(f, k);
+    stream_pull_store(k, f, out);
+}
@@ -3,7 +3,7 @@
 // ApplyEsoPullCurvedKernel, SensorKernel, ForceRegionKernel.
 //
 // Launched on compact lists (n_curved / n_sensor / n_cells threads).
-// Included by uniform.cu.  No standalone compilation.
+// Included by kernel_v2.cu.  No standalone compilation.
 //
 // Double-buffer mode:
 //   CurvedBoundaryKernel runs BEFORE OneStep.
@@ -1,42 +0,0 @@
-// CelerisLab/lbm/kernels/step/block_boundary.cu
-// Receiver-local curved-boundary staging and its raw-exchange accumulation.
-// Part of the blocked.cu compilation entry; relies on its includes and guards.
-
-// Static cut links, receiver-local staging: cell is the receiver's local core
-// cell, so the existing BFL writes the solid-source window image that this
-// block's next pull reads (no halo copy between this kernel and BlockStep).
-// surface_velocity (nullable, 2 floats per link): prescribed fluid velocity on
-// fixed geometry, same convention as CurvedBoundaryKernel. Optional raw rows
-// (jx,jy,torque,dm) are unique physical links, never body-observation slots.
-extern "C" __global__ void BlockCurvedBoundary(
-    fpxx* f, const uint32_t* block, const uint32_t* cell, const unsigned char* dir,
-    const float* q, const unsigned char* fallback, unsigned int count,
-    const float* surface_velocity, const float* rx, const float* ry, float* raw)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    float Uw = 0.0f, Vw = 0.0f;
-    if (surface_velocity != nullptr) {
-        const float u = surface_velocity[2 * row], v = surface_velocity[2 * row + 1];
-        if (u != 0.0f || v != 0.0f) { Uw = u; Vw = v; }
-    }
-    apply_bouzidi_link(dir[row], q[row], cell[row], f + (unsigned long)block[row] * NQ * TOTAL_CELLS,
-                       Uw, Vw, rx ? rx[row] : 0.0f, ry ? ry[row] : 0.0f,
-                       fallback[row], nullptr, -1, raw ? raw + 4ul * row : nullptr,
-                       raw ? raw + 4ul * row + 3 : nullptr);
-}
-
-// Same-stream BFL -> this row-owned accumulation -> pull step. No atomics,
-// no cross-row reduction and no history allocation proportional to substeps.
-extern "C" __global__ void BlockAccumulateExchange(
-    const float* raw, double* integral, unsigned int count, double h, double dt)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    const unsigned long k = 4ul * row;
-    const double impulse = h * dt;
-    integral[k] += impulse * (double)raw[k];
-    integral[k + 1] += impulse * (double)raw[k + 1];
-    integral[k + 2] += h * impulse * (double)raw[k + 2];
-    integral[k + 3] += h * h * (double)raw[k + 3];
-}
@@ -1,12 +1,5 @@
-#if BLOCK_ROOT_BC != 2
-#error "BlockChannelStep requires BLOCK_ROOT_BC == 2"
-#endif
-
 // Root-only blocked counterpart of OneStep's D2Q9/SRT channel closure.
 // NX/NY are LOCAL strides; all physical boundary decisions use global coordinates.
-#include "../core/cell_kind.cuh"
-#include "../operators/bounce_back_swap.cuh"
-#include "../boundary/bounce_back.cuh"
 #include "../boundary/inlet/common.cuh"
 #include "../boundary/inlet/zou_he_local.cuh"
 #include "../boundary/outlet/pressure_neq.cuh"
@@ -22,13 +15,15 @@ extern "C" __global__ void BlockChannelStep(
    unsigned int x, y; unsigned long k;
    index_from_thread(x, y, k);
    if (x < halo || y < halo || x >= NX - halo || y >= NY - halo) return;
-    unsigned int gx, gy;
-    block_global_xy(x, y, halo, d_block_channel.nx, gx, gy);
+    const unsigned int bx = NX - 2 * halo, by = NY - 2 * halo;
+    const unsigned int nbx = d_block_channel.nx / bx;
+    const unsigned int gx = (blockIdx.z % nbx) * bx + x - halo;
+    const unsigned int gy = (blockIdx.z / nbx) * by + y - halo;
    const unsigned long base = (unsigned long)blockIdx.z * NQ * TOTAL_CELLS;
    const unsigned long cell = (unsigned long)blockIdx.z * TOTAL_CELLS + k;
    float f[NQ];
    if (kind != nullptr && kind[cell] == KIND_OUTER) {
-        fill_invalid(f);
+        for (int q = 0; q < NQ; ++q) f[q] = NAN;
    } else {
        unsigned long j[NQ];
        compute_neighbors(x, y, j);
@@ -36,19 +31,44 @@ extern "C" __global__ void BlockChannelStep(
        const bool wall = gy == 0 || gy == d_block_channel.ny - 1;
        const bool outlet = gx == d_block_channel.nx - 1;
        if (wall) {
-            bounce_back_swap(f);  // Wall owns all four corners; ghosts never collide.
+            // Wall owns all four corners. Ghosts pull and swap, never collide.
+            for (int q = 1; q < NQ; q += 2) {
+                const float t = f[q]; f[q] = f[q + 1]; f[q + 1] = t;
+            }
        } else if (gx == 0) {
            apply_zou_he_left_velocity_inlet_d2q9(
                f, inlet_target_u((float)gy, d_block_channel.ny, d_block_channel.velocity), 0.0f);
        } else if (outlet) {
            // Immutable input donor, receiver-local (also valid across a block seam).
            float donor[NQ];
-            load_node(in + base, k - 1, donor);
+            for (int q = 0; q < NQ; ++q)
+                donor[q] = load_ddf(in + base, index_f(k - 1, q));
            apply_pressure_outlet_d2q9(f, donor);
-        } else {
-            apply_wall_bb_d2q9_rows(gy, d_block_channel.ny - 2, f, in + base, k);
+        } else if (gy == 1) {
+            f[3] = load_ddf(in + base, index_f(k, 4));
+            f[5] = load_ddf(in + base, index_f(k, 6));
+            f[8] = load_ddf(in + base, index_f(k, 7));
+        } else if (gy == d_block_channel.ny - 2) {
+            f[4] = load_ddf(in + base, index_f(k, 3));
+            f[6] = load_ddf(in + base, index_f(k, 5));
+            f[7] = load_ddf(in + base, index_f(k, 8));
+        }
+        if (!wall && !outlet) {
+#if COLLISION_MODEL == 2
+            // Match uniform MRT arithmetic (collide_dispatch, zero forcing).
+            float rho, ux, uy;
+            compute_rho_u(f, rho, ux, uy);
+            collide_mrt_no_force(f, rho, ux, uy,
+                fminf(OMEGA_COLLISION_MAX, fmaxf(OMEGA_COLLISION_MIN, d_params.omega)));
+#else
+            // Match uniform SRT arithmetic, including its shifted equilibrium path.
+            float rho, ux, uy, feq[NQ], forcing[NQ] = {};
+            compute_rho_u(f, rho, ux, uy);
+            compute_feq(rho, ux, uy, feq);
+            const float omega = fminf(OMEGA_COLLISION_MAX, fmaxf(OMEGA_COLLISION_MIN, d_params.omega));
+            collide_srt(f, feq, forcing, omega);
+#endif
        }
-        if (!wall && !outlet) block_collide(f);
    }
    stream_pull_store(k, f, out + base);
 }
@@ -1,35 +0,0 @@
-// CelerisLab/lbm/kernels/step/block_step.cu
-// Generic blocked pull/collide/store for periodic/fine and slot/reservoir levels.
-// Part of the blocked.cu compilation entry; relies on its includes and guards.
-#if BLOCK_ROOT_BC == 2
-#error "BlockStep is not built for the channel root (BLOCK_ROOT_BC == 2)"
-#endif
-
-// Pull/collide/store core cells only; halo cells of out are left untouched.
-// flags (block cell ids, nullable): solid cores store NaN and never collide.
-// kind (block cell ids, nullable = all ACTIVE): OUTER skips the pull and
-// stores NaN, INNER pulls without collision, ACTIVE pulls and collides.
-extern "C" __global__ void BlockStep(const fpxx* in, fpxx* out, unsigned int halo,
-                                     const uint16_t* flags, const unsigned char* kind) {
-    unsigned int x, y; unsigned long k;
-    index_from_thread(x, y, k);
-    if (x < halo || y < halo || x >= NX - halo || y >= NY - halo) return;
-    const unsigned long base = (unsigned long)blockIdx.z * NQ * TOTAL_CELLS;
-    const unsigned long cell = (unsigned long)blockIdx.z * TOTAL_CELLS + k;
-    const unsigned char cell_kind = kind != nullptr ? kind[cell] : KIND_ACTIVE;
-    float f[NQ];
-    if (cell_kind == KIND_OUTER || (flags != nullptr && is_solid(flags[cell]))) {
-        fill_invalid(f);
-    } else {
-        unsigned long j[NQ];
-        compute_neighbors(x, y, j);  // Core neighbors stay inside the window: no wrap.
-        stream_pull_load(k, f, in + base, j);
-        if (cell_kind == KIND_ACTIVE) {
-#if BLOCK_ROOT_BC == 1
-            block_wall(f, x, y, halo);
-#endif
-            block_collide(f);
-        }
-    }
-    stream_pull_store(k, f, out + base);
-}
@@ -1,78 +0,0 @@
-// CelerisLab/lbm/kernels/step/block_transfer.cu
-// Same-level halo refresh and 2:1 explosion/coalescence between blocked levels.
-// Part of the blocked.cu compilation entry; relies on its includes and guards.
-
-// Halo refresh: block cell ids b*TOTAL_CELLS+c, sources are always core cells.
-extern "C" __global__ void BlockHaloCopy(
-    fpxx* f, const uint64_t* dst, const uint64_t* src, unsigned int count)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    const uint64_t d = dst[row], s = src[row];
-    fpxx* to = f + (d / TOTAL_CELLS) * NQ * TOTAL_CELLS;
-    const fpxx* from = f + (s / TOTAL_CELLS) * NQ * TOTAL_CELLS;
-    for (unsigned int q = 0; q < NQ; ++q)
-        to[index_f(d % TOTAL_CELLS, q)] = from[index_f(s % TOTAL_CELLS, q)];
-}
-
-// Fixed-patch explosion into blocked fine storage: target = owner block cell
-// id of a patch-ghost cell; donors are parent block cell ids and coarse_cells
-// is the parent's block window size.
-extern "C" __global__ void BlockExplode(
-    const fpxx* coarse, fpxx* fine, const uint64_t* target, const uint64_t* donor,
-    unsigned int count, unsigned long coarse_cells)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    const uint64_t t = target[row];
-    fpxx* to = fine + (t / TOTAL_CELLS) * NQ * TOTAL_CELLS;
-    const uint64_t d = donor[row];
-    const fpxx* from = coarse + (d / coarse_cells) * NQ * coarse_cells;
-    for (unsigned int q = 0; q < NQ; ++q)
-        to[index_f(t % TOTAL_CELLS, q)] = from[q * coarse_cells + d % coarse_cells];
-}
-
-// Experimental Schornbaum--Ruede (arXiv:1508.07982, Algorithm 2)
-// and Chen et al. (doi:10.1016/j.physa.2005.09.036) population interpolation.
-// Independent implementation of the mathematical stencil; no upstream source copied.
-// Stencil cells are owner cores; a disabled axis repeats its center twice.
-extern "C" __global__ void BlockExplodeProjected(
-    const fpxx* coarse, fpxx* fine, const uint64_t* target, const uint64_t* donor,
-    unsigned int count, unsigned long coarse_cells,
-    const uint64_t* neighbors, const float* offsets)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    const uint64_t t = target[row], d = donor[row];
-    fpxx* to = fine + (t / TOTAL_CELLS) * NQ * TOTAL_CELLS;
-    for (unsigned int q = 0; q < NQ; ++q) {
-        float v[4];
-        for (unsigned int a = 0; a < 4; ++a) {
-            const uint64_t n = neighbors[4ul * row + a];
-            v[a] = coarse[(n / coarse_cells) * NQ * coarse_cells
-                          + q * coarse_cells + n % coarse_cells];
-        }
-        float gx = .5f * (v[1] - v[0]), gy = .5f * (v[3] - v[2]);
-        const float ex = d_cx[q], ey = d_cy[q];
-        if (q != 0) {
-            const float along = (ex * gx + ey * gy) / (ex * ex + ey * ey);
-            gx -= ex * along;
-            gy -= ey * along;
-        }
-        to[index_f(t % TOTAL_CELLS, q)] =
-            coarse[(d / coarse_cells) * NQ * coarse_cells + q * coarse_cells + d % coarse_cells]
-            + offsets[2ul * row] * gx + offsets[2ul * row + 1] * gy;
-    }
-}
-
-// Targets are receiver-local SOURCE slots for the immediately following pull.
-// Child summation order ((c0 + c1) + c2) + c3 is part of the numerics; no collision here.
-extern "C" __global__ void BlockCoalesce(
-    const fpxx* fine, fpxx* coarse, const uint64_t* target, const uint64_t* children,
-    unsigned int count)
-{
-    unsigned int row = blockIdx.x * blockDim.x + threadIdx.x;
-    if (row >= count) return;
-    const uint64_t* s = children + 4ul * row;
-    coarse[target[row]] = 0.25f * (fine[s[0]] + fine[s[1]] + fine[s[2]] + fine[s[3]]);
-}
@@ -3,7 +3,7 @@
 //
 // Decodes the EsoPull backing layout into physical distributions, then
 // computes rho/ux/uy.  Output is SoA: rho_out[N], ux_out[N], uy_out[N].
-// Included by uniform.cu.  No standalone compilation.
+// Included by kernel_v2.cu.  No standalone compilation.
 //
 // This kernel is the sole path for macroscopic diagnostics in EsoPull mode.
 // It uses the shared semantic helper layer (esopull_semantic_helpers.cuh).
@@ -5,7 +5,7 @@
 // or encodes physical DDF back to EsoPull backing layout.
 // Each thread handles one cell from a compact index list.
 //
-// Included by uniform.cu.  No standalone compilation.
+// Included by kernel_v2.cu.  No standalone compilation.
 // ============================================================================

 #ifndef CELERIS_STEP_ESOPULL_SYNC_CU
@@ -1,6 +1,6 @@
 // CelerisLab – step/init_flow.cu
 // Channel-flow initialization kernels (double-buffer and EsoPull).
-// Included by uniform.cu after all headers.  No standalone compilation.
+// Included by kernel_v2.cu after all headers.  No standalone compilation.
 // ============================================================================

 #ifndef CELERIS_STEP_INIT_FLOW_CU
@@ -73,9 +73,9 @@ __device__ __forceinline__ uint16_t finalize_domain_flag(
 }

 // ============================================================================
-// InitTubeFlow — double-buffer channel initialization
+// InitTubeFlow_v2 — double-buffer channel initialization
 // ============================================================================
-__global__ void InitTubeFlow(uint16_t* flag, fpxx* fi)
+__global__ void InitTubeFlow_v2(uint16_t* flag, fpxx* fi)
 {
 #if DIM == 2
    unsigned int x, y; unsigned long k;
@@ -1,183 +0,0 @@
-// Translating circles (docs/moving_bodies.md): M1 MovingCircleCells reclassifies
-// band cells and refills uncovered ones; M2 MovingCircleLinks applies the cut links.
-// Geometry comes from an immutable FP64 record per body
-// {cx_old, cy_old, cx_new, cy_new, r, ux, uy}; the M2 operation order mirrors
-// CircleGeometry.build_cut_links / find_circle_intersection with explicit _rn
-// operations (bit parity with the host builder is a test target, not a claim).
-// Moving circles are never in the packed static links, so this kernel is the
-// only writer of their solid slots.
-#ifndef CELERIS_MOVING_CIRCLE_CU
-#define CELERIS_MOVING_CIRCLE_CU
-
-#if DIM == 2
-constexpr int MOVING_BAND_INTS = 6;   // x0, y0, width, height, first_slot, body_id
-constexpr int MOVING_GEOM_DOUBLES = 7;
-// cme_x, cme_y, wen_x, wen_y, link_dm, n_links, cover_jx, cover_jy, cover_mass,
-// uncover_jx, uncover_jy, uncover_mass, eq_only, no_donor, crossings
-constexpr int MOVING_DIAG_FLOATS = 15;
-
-__device__ __forceinline__ double mc_sq(double v) { return __dmul_rn(v, v); }
-
-__device__ __forceinline__ bool mc_inside(int x, int y, double cx, double cy, double r)
-{
-    return __dadd_rn(mc_sq(__dsub_rn((double)x, cx)), mc_sq(__dsub_rn((double)y, cy))) < mc_sq(r);
-}
-
-// Smallest root t in [0, 1] of |p + t c - centre| = r (find_circle_intersection order).
-__device__ __forceinline__ bool mc_hit(int x, int y, int ex, int ey,
-                                       double cx, double cy, double r, double& t)
-{
-    const double dx = (double)ex, dy = (double)ey;
-    const double px = __dsub_rn((double)x, cx), py = __dsub_rn((double)y, cy);
-    const double a = __dadd_rn(mc_sq(dx), mc_sq(dy));
-    const double b = __dmul_rn(2.0, __dadd_rn(__dmul_rn(dx, px), __dmul_rn(dy, py)));
-    const double c = __dsub_rn(__dadd_rn(mc_sq(px), mc_sq(py)), mc_sq(r));
-    const double det = __dsub_rn(mc_sq(b), __dmul_rn(__dmul_rn(4.0, a), c));
-    if (det < 0.0) return false;
-    const double s = __dsqrt_rn(det), a2 = __dmul_rn(2.0, a);
-    const double t1 = __ddiv_rn(__dsub_rn(-b, s), a2);
-    const double t2 = __ddiv_rn(__dadd_rn(-b, s), a2);
-    if (0.0 <= t1 && t1 <= 1.0) { t = t1; return true; }
-    if (0.0 <= t2 && t2 <= 1.0) { t = t2; return true; }
-    return false;
-}
-
-__global__ void MovingCircleLinks(
-    fpxx* fi, const uint16_t* flag,
-    const int* band, const double* geom,
-    unsigned int n_bodies, unsigned int n_slots,
-    const float* action, float* obs, float* diag, float* slot_debug)
-{
-    const unsigned int tid = threadIdx.x + blockIdx.x * blockDim.x;
-    if (tid >= n_slots) return;
-    unsigned int m = 0;
-    while (m + 1 < n_bodies && tid >= (unsigned int)band[(m + 1) * MOVING_BAND_INTS + 4]) ++m;
-    const int* b = band + m * MOVING_BAND_INTS;
-    const unsigned int local = tid - (unsigned int)b[4];
-    const unsigned int dir = local % 8u + 1u;
-    const int x = b[0] + (int)((local / 8u) % (unsigned int)b[2]);
-    const int y = b[1] + (int)((local / 8u) / (unsigned int)b[2]);
-    const double* g = geom + MOVING_GEOM_DOUBLES * m;
-    const double cx = g[2], cy = g[3], r = g[4];
-    const int ex = d_cx[dir], ey = d_cy[dir];
-    float* debug = slot_debug == nullptr ? nullptr : slot_debug + 4 * tid;
-    if (debug != nullptr) debug[0] = -1.0f;
-
-    double t;
-    if (mc_inside(x, y, cx, cy, r) || !mc_inside(x + ex, y + ey, cx, cy, r)
-            || !mc_hit(x, y, ex, ey, cx, cy, r, t))
-        return;
-    const double hx = __dadd_rn((double)x, __dmul_rn(t, (double)ex));
-    const double hy = __dadd_rn((double)y, __dmul_rn(t, (double)ey));
-    const double hdx = __dsub_rn(hx, (double)x), hdy = __dsub_rn(hy, (double)y);
-    const double norm = __dsqrt_rn((double)(ex * ex + ey * ey));
-    double qd = __ddiv_rn(__dsqrt_rn(__dadd_rn(mc_sq(hdx), mc_sq(hdy))), norm);
-    qd = fmax(0.01, fmin(qd, 1.0));
-    const float q = (float)qd;
-    const float rx = (float)__dsub_rn(hx, cx), ry = (float)__dsub_rn(hy, cy);
-
-    // Same two-stage order as build_cut_links + pack_cut_links_to_soa: the fallback
-    // class is chosen from the clamped FP64 q (q < 1/2 needs a fluid donor at x - c);
-    // only then are q, rx, ry rounded to FP32 for the BFL branch and spin velocity.
-    unsigned char fallback = CURVED_FALLBACK_BOUZIDI;
-    if (qd < 0.5) {
-        const int xd = x - ex, yd = y - ey;
-        if (xd < 0 || xd >= (int)NX || yd < 0 || yd >= (int)NY || mc_inside(xd, yd, cx, cy, r)
-                || (flag[linear_index((unsigned int)xd, (unsigned int)yd)] & FLAG_FLUID) == 0)
-            fallback = CURVED_FALLBACK_HALFWAY;
-    }
-    if (debug != nullptr) { debug[0] = q; debug[1] = (float)fallback; debug[2] = rx; debug[3] = ry; }
-
-    const int bid = b[5];
-    const float omega = action_omega(action, bid);
-    const float Uw = (float)g[5] - omega * ry, Vw = (float)g[6] + omega * rx;  // u + omega x r
-    float exchange[3], dm;
-    apply_bouzidi_link(dir, q, linear_index((unsigned int)x, (unsigned int)y), fi,
-                       Uw, Vw, rx, ry, fallback, obs, bid, exchange, &dm);
-    if (diag != nullptr) {
-        float* d = diag + m * MOVING_DIAG_FLOATS;
-        atomicAdd(&d[0], exchange[0]);
-        atomicAdd(&d[1], exchange[1]);
-        atomicAdd(&d[2], Uw * dm);   // Wen 2014 correction -u_w (f_t - f_r)
-        atomicAdd(&d[3], Vw * dm);
-        atomicAdd(&d[4], dm);
-        atomicAdd(&d[5], 1.0f);
-    }
-}
-// M1: one thread per band cell, launched only on steps with c_old != c_new.
-// Membership comes from the immutable old/new predicates, never from flags, so
-// classification, refill and the flag write of one cell cannot race with another.
-// ddf holds post-collision G^{n-1}; refilled cells get all nine slots at that level.
-__global__ void MovingCircleCells(
-    fpxx* fi, uint16_t* flag, const int* band, const double* geom,
-    unsigned int n_bodies, unsigned int n_cells, const float* action, float* diag)
-{
-    const unsigned int tid = threadIdx.x + blockIdx.x * blockDim.x;
-    if (tid >= n_cells) return;
-    unsigned int m = 0;
-    while (m + 1 < n_bodies && tid >= (unsigned int)band[(m + 1) * MOVING_BAND_INTS + 4] / 8u) ++m;
-    const int* b = band + m * MOVING_BAND_INTS;
-    const unsigned int local = tid - (unsigned int)b[4] / 8u;
-    const int x = b[0] + (int)(local % (unsigned int)b[2]);
-    const int y = b[1] + (int)(local / (unsigned int)b[2]);
-    const double* g = geom + MOVING_GEOM_DOUBLES * m;
-    const bool in_old = mc_inside(x, y, g[0], g[1], g[4]);
-    const bool in_new = mc_inside(x, y, g[2], g[3], g[4]);
-    if (in_old == in_new) return;
-    const unsigned long k = linear_index((unsigned int)x, (unsigned int)y);
-    float* d = diag + m * MOVING_DIAG_FLOATS;
-    float rho = 0.0f, jx = 0.0f, jy = 0.0f;
-    if (in_new) {  // covered: its fluid content leaves the active set
-        for (unsigned int i = 0; i < NQ; ++i) {
-            const float f = load_ddf(fi, index_f(k, i));
-            rho += f; jx += (float)d_cx[i] * f; jy += (float)d_cy[i] * f;
-        }
-        flag[k] = FLAG_SOLID | FLAG_OBSTACLE | FLAG_BC_CURVED;
-        atomicAdd(&d[6], jx); atomicAdd(&d[7], jy); atomicAdd(&d[8], rho);
-        atomicAdd(&d[14], 1.0f);
-        return;
-    }
-    // Uncovered: donors are fluid in BOTH geometries; NEQ from the neighbour with the
-    // largest unnormalized c.n > 0 (first direction wins ties), n from c_new.
-    const float nx = (float)__dsub_rn((double)x, g[2]), ny = (float)__dsub_rn((double)y, g[3]);
-    float rho_sum = 0.0f, best_dot = 0.0f;
-    int n_valid = 0, best = -1;
-    for (unsigned int i = 1; i < NQ; ++i) {
-        const int xn = x + d_cx[i], yn = y + d_cy[i];
-        if (mc_inside(xn, yn, g[0], g[1], g[4]) || mc_inside(xn, yn, g[2], g[3], g[4])) continue;
-        const unsigned long kn = linear_index((unsigned int)xn, (unsigned int)yn);
-        for (unsigned int q = 0; q < NQ; ++q) rho_sum += load_ddf(fi, index_f(kn, q));
-        ++n_valid;
-        const float dot = (float)d_cx[i] * nx + (float)d_cy[i] * ny;
-        if (dot > best_dot) { best_dot = dot; best = (int)i; }
-    }
-    const float omega = action_omega(action, b[5]);
-    const float uwx = (float)g[5] - omega * ny, uwy = (float)g[6] + omega * nx;  // at the cell
-    float feq[NQ], neq[NQ];
-    compute_feq(n_valid > 0 ? rho_sum / (float)n_valid : (float)RHO, uwx, uwy, feq);
-    for (unsigned int i = 0; i < NQ; ++i) neq[i] = 0.0f;
-    if (best >= 0) {
-        const unsigned long kd = linear_index((unsigned int)(x + d_cx[best]), (unsigned int)(y + d_cy[best]));
-        float gd[NQ], rd = 0.0f, mx = 0.0f, my = 0.0f, fd[NQ];
-        for (unsigned int i = 0; i < NQ; ++i) {
-            gd[i] = load_ddf(fi, index_f(kd, i));
-            rd += gd[i]; mx += (float)d_cx[i] * gd[i]; my += (float)d_cy[i] * gd[i];
-        }
-        compute_feq(rd, mx / rd, my / rd, fd);
-        for (unsigned int i = 0; i < NQ; ++i) neq[i] = gd[i] - fd[i];
-    } else {
-        atomicAdd(&d[12], 1.0f);
-    }
-    if (n_valid == 0) atomicAdd(&d[13], 1.0f);  // hard failure, checked before commit
-    for (unsigned int i = 0; i < NQ; ++i) {
-        const float f = feq[i] + neq[i];
-        store_ddf(fi, index_f(k, i), f);
-        rho += f; jx += (float)d_cx[i] * f; jy += (float)d_cy[i] * f;
-    }
-    flag[k] = FLAG_FLUID;
-    atomicAdd(&d[9], jx); atomicAdd(&d[10], jy); atomicAdd(&d[11], rho);
-    atomicAdd(&d[14], 1.0f);
-}
-#endif  // DIM == 2
-
-#endif  // CELERIS_MOVING_CIRCLE_CU
@@ -1,6 +1,6 @@
 // CelerisLab – step/one_step_double.cu
 // Double-buffer PULL streaming step kernel.
-// Included by uniform.cu.  No standalone compilation.
+// Included by kernel_v2.cu.  No standalone compilation.
 // ============================================================================

 #ifndef CELERIS_STEP_ONE_STEP_DOUBLE_CU
@@ -1,6 +1,6 @@
 // CelerisLab – step/one_step_esopull.cu
 // Esoteric-Pull single-buffer step kernel.
-// Included by uniform.cu.  No standalone compilation.
+// Included by kernel_v2.cu.  No standalone compilation.
 //
 // CURVED BC: supported via PrepareEsoPullCurvedKernel + ApplyEsoPullCurvedKernel
 // in aux_kernels.cu, launched by stepper.py before EsoPullStep.
@@ -21,14 +21,6 @@
 //   i.e. the population traveling in direction i at node n
 //   arrived from the node at n - c_i  = neighbor in direction opp(i)
 // ---------------------------------------------------------------------------
-// load_node: all NQ populations of node n as stored (no streaming).
-__device__ __forceinline__ void load_node(const fpxx* __restrict__ fi, unsigned long n,
-                                          float* __restrict__ f)
-{
-    for (int q = 0; q < NQ; ++q)
-        f[q] = load_ddf(fi, index_f(n, q));
-}
-
 __device__ __forceinline__ void stream_pull_load(unsigned long n,
                                                 float* __restrict__ f,
                                                 const fpxx* __restrict__ fi,
@@ -115,16 +115,10 @@ class FixedPatch2D:
        return self.bounds[0] - HALO / 2, self.bounds[1] - HALO / 2

    @property
-    def fine_level_offset(self) -> tuple[int, int]:
-        """Array index (y, x) of this window's first cell on the level-wide 2:1 fine grid
-        (an index offset, not an (x, y) origin)."""
+    def fine_level_origin(self) -> tuple[int, int]:
+        """(y, x) of this window's first cell on the level-wide 2:1 fine grid."""
        return 2 * self.bounds[1] - HALO, 2 * self.bounds[0] - HALO

-    @property
-    def rectangles(self) -> tuple:
-        """The one parent rectangle, as a sequence like FixedPatchSet2D.rectangles."""
-        return (self.bounds,)
-
    @property
    def covered(self) -> np.ndarray:
        """Dense coarse mask of cells replaced by the patch (not leaves)."""
@@ -157,6 +151,7 @@ class FixedPatch2D:
            raise ValueError("levels are not synchronized: fine_steps must equal 2*coarse_steps")


+MIN_PATCH_GAP = 4  # Legacy exported constant; union transfers impose no gap policy.


@dataclass(frozen=True, eq=False)
@@ -230,18 +225,11 @@ class FixedPatchSet2D:
    def bounds(self) -> tuple:
        return tuple(p.bounds for p in self.patches)

-    rectangles = bounds
-
    @property
    def fine_origin(self) -> tuple[float, float]:
        """Lower edge of the level-wide fine grid in coarse physical units."""
        return 0.0, 0.0

-    @property
-    def fine_level_offset(self) -> tuple[int, int]:
-        """The level-wide grid itself: zero (y, x) index offset."""
-        return 0, 0
-
    @property
    def covered(self) -> np.ndarray:
        mask = np.zeros(self.coarse_shape, bool)
@@ -8,7 +8,7 @@ from dataclasses import dataclass, replace
 import numpy as np

 from .blocks import blocked_link_tables
-from ..body.jets import _surface_links
+from ..body.jets import jet_link_shapes, surface_link_velocity
 from .descriptors import D2Q9_EX, D2Q9_EY
 from .refinement import ACTIVE, OUTER_GHOST

@@ -36,7 +36,7 @@ def blocked_kind(layout, dense_kind):
    kind[owner[owned]] = np.asarray(dense_kind).ravel()[owned]
    return kind

-def blocked_coarse_tables(patch, layout, order, wall_aware=False, *, composed_kind=None):
+def blocked_base_tables(patch, layout, order, wall_aware=False, *, composed_kind=None):
    """Parent donor cells and receiver-local arrival slots, in transfer row order.

    Stage arrivals only after child reads and parent halo gather, immediately
@@ -130,8 +130,6 @@ class _BlockedBoundary:
    interval_integral: object = None
    accumulate: object = None
    window_integral: object = None  # optional observation-window FP64 ledger
-    spacing: float = None  # level spacing h_l in root units (exchange scaling)
-    centers: tuple = ()    # body reference centers in the root edge frame


 def _prepare_blocked_boundary(boundary, layout, cfg, jets, *, _shifted_blocked=False):
@@ -144,13 +142,11 @@ def _prepare_blocked_boundary(boundary, layout, cfg, jets, *, _shifted_blocked=F
    tables.update(body_id=np.asarray(body_id, np.int32), rx=np.asarray(rx, np.float32),
                  ry=np.asarray(ry, np.float32), aperture=np.zeros(len(dirs), bool))
    actuated = bool(jets) or any(o.surface_actuation is not None for o in boundary.objects)
-    jet_cache = None
    if actuated:
        cfg = replace(cfg)
        cfg.validate()
-        tables["surface_velocity"], tables["aperture"], shape, jet_id = _surface_links(
+        tables["surface_velocity"], tables["aperture"] = surface_link_velocity(
            boundary.objects, cfg, boundary.flags, fluid_idx, dirs, body_id, rx, ry,
            jets=jets, hits=boundary.curved_hits, _shifted_blocked=_shifted_blocked)
-        if jets:
-            jet_cache = (shape, jet_id)
-    return _BlockedBoundary(boundary, tables, jets, actuated, jet_cache)
+    return _BlockedBoundary(boundary, tables, jets, actuated,
+                            jet_link_shapes(jets, boundary.curved_hits) if jets else None)
@@ -20,10 +20,6 @@ class LBMStepper:
        self.cfg = cfg

        self._esopull = (cfg.streaming == "esopull")
-        # Set by the owner when a step would be wrong (translating circles
-        # without attached moving tables, a pending target, or a failed step).
-        self.blocked: str | None = None
-        self.moving = None  # MovingTables attached by the owner (translating circles)

        if self._esopull:
            self.step_fn = module.get_function("EsoPullStep")
@@ -32,17 +28,13 @@ class LBMStepper:
            self.boundary_values_gpu = cuda.mem_alloc((6 * cfg.nx + 2 * cfg.ny * cfg.nq) * 4)
        else:
            self.step_fn = module.get_function("OneStep")
-            self.init_fn = module.get_function("InitTubeFlow")
+            self.init_fn = module.get_function("InitTubeFlow_v2")

        self.curved_fn = module.get_function("CurvedBoundaryKernel")
        self.prepare_esopull_curved_fn = module.get_function("PrepareEsoPullCurvedKernel")
        self.apply_esopull_curved_fn = module.get_function("ApplyEsoPullCurvedKernel")
        self.sensor_fn = module.get_function("SensorKernel")
        self.force_region_fn = module.get_function("ForceRegionKernel")
-        # Moving-circle kernels exist only in D2Q9 double-buffer modules.
-        moving = not self._esopull and cfg.is_d2q9
-        self.moving_fn = module.get_function("MovingCircleLinks") if moving else None
-        self.moving_cells_fn = module.get_function("MovingCircleCells") if moving else None

        tpb = cfg.threads_per_block
        self.block = (tpb, 1, 1)
@@ -78,13 +70,6 @@ class LBMStepper:
        stream: cuda.Stream | None = None,
    ):
        """Advance *n* time steps."""
-        if n > 0 and self.blocked is not None:
-            raise RuntimeError(self.blocked)
-        self._step(n, action_gpu=action_gpu, obs_gpu=obs_gpu, stream=stream)
-
-    def _step(self, n, *, action_gpu, obs_gpu, stream=None, advance=False):
-        """Unguarded steps; ``advance`` runs one step that moves translating circles."""
-        assert not advance or n == 1
        f = self.field
        launch_kw = {}
        if stream is not None:
@@ -96,8 +81,6 @@ class LBMStepper:
                    f.ddf_gpu, self.boundary_values_gpu, np.uint64(self._step_count),
                    block=self.block, grid=self.boundary_grid, **launch_kw,
                )
-            if self.moving is not None:
-                self._launch_moving(action_gpu, obs_gpu, advance, **launch_kw)
            self._launch_curved(action_gpu, obs_gpu, **launch_kw)

            if self._esopull:
@@ -123,21 +106,6 @@ class LBMStepper:
            # Any completed GPU step invalidates host DDF mirror.
            f.invalidate_host_ddf_cache()

-    def _launch_moving(self, action_gpu, obs_gpu, advance, **launch_kw):
-        m, tpb = self.moving, self.cfg.threads_per_block
-        if advance:  # M1 completes before M2 on the same stream
-            self.moving_cells_fn(
-                self.field.ddf_gpu, self.field.flag_gpu, m.band_gpu, m.geom_gpu,
-                np.uint32(m.n_bodies), np.uint32(m.n_cells), action_gpu, m.diag_gpu,
-                block=(tpb, 1, 1), grid=((m.n_cells + tpb - 1) // tpb, 1, 1), **launch_kw,
-            )
-        self.moving_fn(
-            self.field.ddf_gpu, self.field.flag_gpu, m.band_gpu, m.geom_gpu,
-            np.uint32(m.n_bodies), np.uint32(m.n_slots), action_gpu, obs_gpu,
-            m.diag_gpu, m.slot_debug_gpu if m.slot_debug_gpu is not None else np.uintp(0),
-            block=(tpb, 1, 1), grid=((m.n_slots + tpb - 1) // tpb, 1, 1), **launch_kw,
-        )
-
    def _launch_curved(self, action_gpu, obs_gpu, **launch_kw):
        f = self.field
        if f.n_curved == 0:
@@ -25,14 +25,7 @@ import pycuda.driver as cuda

 from .config import LBMConfig, BodyConfig, load_lbm_config, load_body_config
 from .cuda.context import CudaContext, context_bound
-from .cuda import compiler
-from .lbm.descriptors import FLUID
-
-# Translating circles step only through their moving tables (attached at initialize).
-PENDING_BLOCKED = "a pending translation target is advanced only by Simulation.run(1)"
-MOVING_BLOCKED = ("translating circles need the moving kernels and their tables (attached "
-                  "at initialize); "
-                  "positive-step runs are rejected")
+from .cuda import compiler_v2 as compiler
 from .lbm.field import LBMField
 from .lbm.stepper import LBMStepper
 from .body.objects import SimObject
@@ -53,8 +46,8 @@ class Simulation:
                 device_id: int = 0):
        # Internal stream for async DTOH coordination
        self._stream: Optional[cuda.Stream] = None
+        self._build_dir = None
        self._closed = False
-        self._failed = None  # reason after an uncertain device write; only close() remains

        # Load configs
        self.lbm_cfg = load_lbm_config(lbm_config_path)
@@ -66,7 +59,9 @@ class Simulation:
        try:
            with self.ctx.activate():
                arch = self._resolve_compile_arch()
-                self._module = compiler.build_module(self.lbm_cfg, "uniform.cu", arch=arch)
+                self._build_dir = compiler.generate_config(self.lbm_cfg, n_objects=0)
+                self._ptx_path = compiler.compile_kernel(arch=arch, build_dir=self._build_dir)
+                self._module = compiler.load_module(self._ptx_path)
                self._compiled_n_objects = 0
                self._allocation_signature = self.lbm_cfg.allocation_signature()
                self._compiled_viscosity = self.lbm_cfg.viscosity
@@ -97,15 +92,13 @@ class Simulation:
    @context_bound
    def stream(self) -> cuda.Stream:
        """Internal CUDA stream for async DTOH coordination."""
-        self._require_usable()
        if self._stream is None:
            self._stream = cuda.Stream()
        return self._stream

    # -- Object management ---------------------------------------------------
    def add_body(self, type: str = "circle", center=None,
-                 radius: float = 0.0, *, surface_actuation=None, translation=None,
-                 **kwargs) -> int:
+                 radius: float = 0.0, *, surface_actuation=None, **kwargs) -> int:
        """Add a simulation body. Returns body_id.

        Before ``initialize()`` the object is added to the formal registry
@@ -121,10 +114,6 @@ class Simulation:
                angle, half_width (radians), normal_velocity (positive outward).
                D2Q9/FP32/unshifted/DB only; set before initialization or stage
                a new body. No runtime motion or amplitude setter.
-            translation: ``body.motion.Translation`` declaring a translating
-                circle (before initialize only; docs/moving_bodies.md).
-                Positive-step runs are rejected until ``initialize()`` has
-                attached its moving tables.
            **kwargs: passed to the geometry constructor.

        Returns:
@@ -135,10 +124,6 @@ class Simulation:
        type_lower = str(type).strip().lower()
        if surface_actuation is not None and type_lower != "circle":
            raise ValueError("Surface actuation is only supported on circles")
-        if translation is not None and (type_lower != "circle" or surface_actuation is not None
-                                        or self._initialized):
-            raise ValueError("translation needs a circle without surface actuation, "
-                             "added before initialize()")

        if type_lower == "circle":
            from .body.geometry.circle import CircleGeometry
@@ -147,11 +132,6 @@ class Simulation:
            obj = SimObject(obj_id=-1, geometry=geom,
                            center=center, radius=radius,
                            is_sensor=False, surface_actuation=surface_actuation)
-            if translation is not None:
-                from .body.motion import MovingCircle
-                obj.motion = MovingCircle((cx, cy), radius, translation,
-                                          on_failure=self._fail_moving)
-                self.stepper.blocked = MOVING_BLOCKED
        elif type_lower == "sensor":
            from .body.geometry.circle import CircleGeometry
            cx, cy = float(center[0]), float(center[1])
@@ -195,109 +175,15 @@ class Simulation:
    def set_jet_amplitude(self, index: int, amplitude: float) -> None:
        """Change one jet's signed amplitude; re-uploads per-link velocity only.

-        Invalid input raises before any change. Any error after validation
-        (stream creation or upload) leaves the host amplitude unchanged but the
-        device column undefined, so the Simulation is marked failed: every later
-        device-touching public method (incl. ``stream``) raises; close() still
-        works. Close and recreate it.
+        Invalid input changes nothing. A device error leaves the host amplitude
+        unchanged but the device column undefined: treat it like any other CUDA
+        exception here and close/recreate the Simulation before stepping again.
        """
-        self._require_usable()
        jet = self.bodies.jets[index].with_amplitude(amplitude)
        if self._initialized:
-            try:
-                self.field.curved.set_jet_amplitude(index, amplitude, self.stream)
-            except BaseException as exc:
-                self._failed = f"jet amplitude upload failed: {exc!r}"
-                raise
+            self.field.curved.set_jet_amplitude(index, amplitude, self.stream)
        self.bodies.jets[index] = jet  # later geometry syncs keep the new amplitude

-    def _fail_moving(self, exc: BaseException) -> None:
-        # Device geometry is unknown after a failed moving step: same lifecycle as Jets.
-        self._failed = f"moving circle step failed: {exc!r}"
-        self.stepper.blocked = self._failed  # direct stepper calls are refused as well
-
-    def _attach_moving(self) -> None:
-        # Direct stepper calls stay blocked until the moving tables exist.
-        tables = getattr(self, "_moving_tables", None)
-        self.stepper.moving = tables
-        moving = self._moving_bodies()
-        if moving and tables is None:
-            self.stepper.blocked = MOVING_BLOCKED
-        elif any(obj.motion.pending is not None for obj in moving):
-            self.stepper.blocked = PENDING_BLOCKED  # direct steps never consume a target
-        else:
-            self.stepper.blocked = None
-
-    def _build_moving_tables(self):
-        moving = self._moving_bodies()
-        if not moving:
-            return None
-        from .body.motion import MovingTables
-        return MovingTables.upload([(obj.motion, obj.obj_id) for obj in moving])
-
-    @context_bound
-    def moving_diagnostics(self) -> np.ndarray:
-        """Per translating circle (in body order), columns ``MovingTables.DIAG``,
-        accumulated since obs were last zeroed (diagnostics only, not a force RHS)."""
-        self._require_usable()
-        tables = self.stepper.moving
-        if tables is None:
-            from .body.motion import MovingTables
-            return np.zeros((0, MovingTables.DIAG_FLOATS), np.float32)
-        self.stream.synchronize()
-        return tables.download_diagnostics()
-
-    def _moving_bodies(self):
-        return [obj for obj in self.bodies.objects if obj.motion is not None]
-
-    def _reject_moving_bodies(self, operation: str) -> None:
-        if self._moving_bodies():
-            raise ValueError(f"{operation} is not supported with translating circles")
-
-    def _validate_moving_bodies(self) -> None:
-        """Reject unsupported modes and swept-band placement before any mutation."""
-        moving = self._moving_bodies()
-        if not moving:
-            return
-        from .body.motion import SHARED_CLEARANCE, validate_shared_translations
-        validate_shared_translations([obj.motion for obj in moving])
-        cfg = self.lbm_cfg
-        if (not cfg.is_d2q9 or cfg.streaming != "double_buffer" or cfg.ddf_shifting
-                or cfg.store_precision != "FP32"):
-            raise ValueError("translating circles need D2Q9/FP32/unshifted/double_buffer")
-        if self.bodies.jets:
-            raise ValueError("Jets are not supported together with translating circles")
-        nx, ny = self.field.nx, self.field.ny
-        base = self.field.build_channel_flags().reshape(ny, nx)
-        for obj in moving:
-            x0, x1, y0, y1 = obj.motion.band()
-            if x0 < 1 or y0 < 1 or x1 > nx - 2 or y1 > ny - 2:
-                raise ValueError(f"swept band {(x0, x1, y0, y1)} touches the domain edge")
-            if not np.all((base[y0:y1 + 1, x0:x1 + 1] & FLUID) != 0):
-                raise ValueError(f"swept band {(x0, x1, y0, y1)} contains non-fluid base cells")
-            for other in self.bodies.objects:
-                if other is obj:
-                    continue
-                (cx, cy), r = other.center[:2], float(other.radius)
-                if (other.motion is not None and obj.motion.translation.shared
-                        and obj.motion.translation is other.motion.translation):
-                    # Whole envelopes may overlap; simultaneous local stencils may not.
-                    gap = np.hypot(obj.center[0] - cx, obj.center[1] - cy) - obj.radius - r
-                    if gap <= SHARED_CLEARANCE:
-                        raise ValueError("shared translation needs surface clearance > 4 cells")
-                    continue
-                if other.motion is not None:
-                    ox0, ox1, oy0, oy1 = other.motion.band()
-                else:
-                    ox0, ox1, oy0, oy1 = cx - r - 2, cx + r + 2, cy - r - 2, cy + r + 2
-                if ox0 <= x1 and x0 <= ox1 and oy0 <= y1 and y0 <= oy1:
-                    raise ValueError(f"swept band {(x0, x1, y0, y1)} overlaps body {other.obj_id}")
-
-    def _require_usable(self):
-        failed = getattr(self, "_failed", None)
-        if failed is not None:
-            raise RuntimeError(f"Simulation failed ({failed}); close() and recreate it")
-
    def remove_body(self, id: int) -> None:
        """Remove a body from the simulation.

@@ -363,7 +249,7 @@ class Simulation:

    # -- Runtime control -----------------------------------------------------
    def set_body(self, id: int, omega: float = None,
-                 vx: float = None, vy: float = None, offset=None) -> None:
+                 vx: float = None, vy: float = None) -> None:
        """Set runtime body state (host action array only, no H2D).

        The GPU action buffer is updated at the next ``run()`` call.
@@ -371,26 +257,10 @@ class Simulation:
        Args:
            id: body_id from add_body().
            omega: rotation speed (lattice units).  ``None`` = no change.
-            vx: translation velocity x. For a translating circle: the
-                interval wall velocity of the target, only together with
-                ``offset``; otherwise stored in the body state (not applied
-                to stationary walls).  ``None`` = no change.
-            vy: translation velocity y; same rules as ``vx``.
-            offset: target centre offset of a translating circle; with vx/vy
-                (default 0) it replaces the pending target after validation
-                against the applied offset (docs/moving_bodies.md, 4a). Only
-                ``run(1)`` advances it; direct stepper calls are blocked meanwhile.
+            vx: translation velocity x (future).  ``None`` = no change.
+            vy: translation velocity y (future).  ``None`` = no change.
        """
        obj = self.bodies.get(id)
-        motion = obj.motion
-        if motion is not None:
-            if offset is None and (vx is not None or vy is not None):
-                raise ValueError("a translating circle takes vx/vy only with an offset")
-            target = None if offset is None else motion.check_target(
-                offset, (0.0 if vx is None else vx, 0.0 if vy is None else vy))
-            vx = vy = None  # the motion target, not ObjectState, owns translation
-        elif offset is not None:
-            raise ValueError(f"body {id} was not declared with a translation")
        proposed = dict(vars(obj.state))
        proposed.update({k: float(v) for k, v in (("omega", omega), ("vx", vx), ("vy", vy))
                         if v is not None})
@@ -406,9 +276,6 @@ class Simulation:
        if vy is not None:
            obj.state.vy = float(vy)
            changed = True
-        if motion is not None and target is not None:
-            motion.pending = target
-            self._attach_moving()
        if changed:
            self.bodies._refresh_action_from_objects()

@@ -469,20 +336,13 @@ class Simulation:
    def read_surface_exchange(self, id: int):
        """Latest step's wall/aperture (Fx,Fy,Tz) exchange, not total nozzle force.

-        Supports SurfaceActuation and Jet-driven bodies, including zero-amplitude
-        apertures. Passive bodies without an aperture are rejected.
        Unlike read_body this is not accumulated/time-averaged. It resets after
        geometry sync or checkpoint load; advance before interpreting it.
        """
-        self._require_usable()
-        obj = self.bodies.get(id)
-        curved = self.field.curved
-        has_aperture = (curved.aperture is not None
-                        and np.any(curved.aperture & (curved.body_id == id)))
-        if obj.surface_actuation is None and not has_aperture:
+        if self.bodies.get(id).surface_actuation is None:
            raise ValueError("Body has no surface actuation")
        self.stream.synchronize()
-        return curved.surface_exchange(id)
+        return self.field.curved.surface_exchange(id)

    @context_bound
    def read_body(self, id: int, *,
@@ -502,7 +362,6 @@ class Simulation:
            BodyTelemetry with fields ``force``, ``torque``, ``sensor``.
            ``sensor`` is a dim-length array of zeros for non-sensor bodies.
        """
-        self._require_usable()
        if self.bodies.obs_pinned is None:
            raise RuntimeError("No obs buffer. Call run() first.")
        if stream is None:
@@ -522,7 +381,6 @@ class Simulation:
        This is the most efficient readback for DRL control loops
        (single contiguous D2H copy, no Python per-body overhead).
        """
-        self._require_usable()
        if self.bodies.obs_pinned is None:
            raise RuntimeError("No obs buffer. Call run() first.")
        if stream is None:
@@ -548,8 +406,15 @@ class Simulation:
        self.lbm_cfg.validate_runtime()
        self._assert_allocation_contract()
        arch = self._resolve_compile_arch()
-        self._module = compiler.build_module(self.lbm_cfg, "uniform.cu", arch=arch,
-                                             n_objects=expected_n_objects)
+        next_dir = compiler.generate_config(self.lbm_cfg, n_objects=expected_n_objects)
+        try:
+            next_ptx = compiler.compile_kernel(arch=arch, build_dir=next_dir)
+            next_module = compiler.load_module(next_ptx)
+        except Exception:
+            compiler.cleanup_build_dir(next_dir)
+            raise
+        old_dir = self._build_dir
+        self._build_dir, self._ptx_path, self._module = next_dir, next_ptx, next_module
        self._compiled_n_objects = int(expected_n_objects)

        # Reconnect field and stepper to new module
@@ -565,9 +430,9 @@ class Simulation:
            self.field, self._module, self.lbm_cfg,
        )
        self.stepper._step_count = _prev_step_count
-        self._attach_moving()

        self._assert_object_count_contract(expected_count=expected_n_objects)
+        compiler.cleanup_build_dir(old_dir)

    def recompile(self):
        """Re-generate config headers and recompile kernel.
@@ -586,31 +451,23 @@ class Simulation:
    @context_bound
    def initialize(self):
        """Initialize flow field and sync objects to GPU."""
-        self._require_usable()
-        self._assert_allocation_contract()
-        # Validate the complete geometry before flags, populations or modules
-        # change. Compact-list construction publishes no outputs on failure.
-        next_flags = self.bodies.build_flags(self.field.build_channel_flags())
-        self._validate_moving_bodies()
-        self._attach_moving()
-        if self.bodies.jets and self.bodies.count == 0:
-            raise ValueError("Jets need bodies with cut links")
-        self.bodies.build_compact_lists_for(self.bodies.objects, next_flags)
-
        # Recompile if objects were added after construction.
+        self._assert_allocation_contract()
        if self._read_generated_n_objects() != self.bodies.count:
            self.recompile()

-        self.field.flag = next_flags
+        self.field.flag = self.field.build_channel_flags()
+        if self.bodies.count > 0:
+            self.field.flag = self.bodies.build_flags(self.field.flag)
        self.field.upload_flags()

+        if self.bodies.jets and self.bodies.count == 0:
+            raise ValueError("Jets need bodies with cut links")
        self.stepper.initialize()
        if self.bodies.count > 0:
            self.bodies.sync_to_gpu(self.field, rebuild_flags=False)
        else:
            self.bodies.ensure_packed_buffers()
-        self._moving_tables = self._build_moving_tables()
-        self._attach_moving()
        self._assert_runtime_contracts()
        self._initialized = True

@@ -623,10 +480,8 @@ class Simulation:
        In EsoPull mode, the backing layout is decoded to physical DDF on
        GPU for the patched cells only, patched on host, then encoded back.
        """
-        self._require_usable()
        if not self._initialized:
            raise RuntimeError("Call initialize() before sync_bodies()")
-        self._reject_moving_bodies("sync_bodies()")

        self._assert_allocation_contract()
        # 1. Synchronize GPU
@@ -720,23 +575,12 @@ class Simulation:
                sensor) on GPU and reset the step accumulator before stepping.
            checkpoint_interval: Nonnegative integer; if >0, save every N steps.
        """
-        self._require_usable()
        if not self._initialized:
            raise RuntimeError("Call initialize() first")
        steps = operator.index(steps)
        checkpoint_interval = operator.index(checkpoint_interval)
        if steps < 0 or checkpoint_interval < 0:
            raise ValueError("steps and checkpoint_interval must be nonnegative")
-        moving = self._moving_bodies()
-        if steps > 0 and moving:
-            from .body.motion import validate_shared_translations
-            validate_shared_translations([obj.motion for obj in moving])
-        if steps > 0 and moving and self.stepper.moving is None:
-            raise RuntimeError(MOVING_BLOCKED)
-        if moving and checkpoint_interval > 0:
-            raise ValueError("checkpoints are not supported with translating circles")
-        if steps > 1 and any(obj.motion.pending is not None for obj in moving):
-            raise ValueError("a pending translation target needs run(1)")
        self._assert_runtime_contracts()
        # Discard any uncommitted body edits before stepping.
        if self.bodies.has_pending_edit():
@@ -753,8 +597,6 @@ class Simulation:
        # Zero obs segments before step group
        if zero_obs:
            self.bodies.zero_obs_async(stream)
-            if self.stepper.moving is not None:
-                self.stepper.moving.zero_diagnostics(stream)

        if checkpoint_interval > 0:
            done = 0
@@ -771,9 +613,6 @@ class Simulation:
                if done < steps or done % checkpoint_interval == 0:
                    stream.synchronize()
                    self.save_checkpoint()
-        elif self.stepper.moving is not None and steps > 0:
-            self._run_moving(steps, stream, sync_obs)
-            return
        else:
            self.stepper.step(
                steps,
@@ -792,37 +631,6 @@ class Simulation:

        stream.synchronize()

-    def _run_moving(self, steps, stream, sync_obs):
-        """Steps with translating circles: hold, or one advancing step that commits
-        each pending target only after synchronization and a zero ``no_donor`` count
-        (docs/moving_bodies.md 4a, 5). Any failure leaves the Simulation unusable."""
-        tables = self.stepper.moving
-        circles = [(obj.motion, obj.obj_id) for obj in self._moving_bodies()]
-        pending = any(motion.pending is not None for motion, _ in circles)
-        try:
-            advancing = tables.upload_records(circles, stream)
-            self.stepper._step(steps, action_gpu=self.bodies.action_gpu,
-                               obs_gpu=self.bodies.obs_gpu, stream=stream, advance=advancing)
-            self.bodies.increment_obs_steps(steps)
-            if sync_obs:
-                self.bodies.download_obs_full_async(stream)
-            stream.synchronize()
-            if advancing:
-                no_donor = tables.download_diagnostics()[:, tables.DIAG.index("no_donor")]
-                if np.any(no_donor > 0):
-                    raise RuntimeError("translating circle refill found no donor cell")
-            if pending:  # a target equal to the applied offset is consumed as a hold step
-                for motion, _ in circles:
-                    motion.commit()
-                if advancing:
-                    tables.upload_records(circles, stream)  # first hold: old = new = applied, u = 0
-                    stream.synchronize()
-                self._attach_moving()
-        except BaseException as exc:
-            for motion, _ in circles:  # device geometry/state unknown after any failure
-                motion.fail(exc)
-            raise
-
    def step(self, n: int = 1):
        """Advance *n* steps (convenience for interactive use)."""
        self.run(n)
@@ -831,25 +639,15 @@ class Simulation:
    @context_bound
    def get_macroscopic(self) -> Dict[str, np.ndarray]:
        """Download DDF and return rho, ux, uy [, uz]."""
-        self._require_usable()
        return self.field.get_macroscopic(step_id=self.stepper.step_count)

    @context_bound
    def get_ddf(self) -> np.ndarray:
-        self._require_usable()
        self.field.download_ddf(step_id=self.stepper.step_count)
        return self.field.ddf.copy()

-    @context_bound
    def get_flags(self) -> np.ndarray:
-        """Flag array; read back from the device when translating circles may have moved."""
-        if getattr(self.stepper, "moving", None) is None:
-            return self.field.flag.copy()
-        self._require_usable()
-        self.stream.synchronize()
-        flags = np.empty_like(self.field.flag)
-        cuda.memcpy_dtoh(flags, self.field.flag_gpu)
-        return flags
+        return self.field.flag.copy()

    # -- Runtime parameter updates -------------------------------------------
    @context_bound
@@ -858,29 +656,24 @@ class Simulation:

        Accepted: omega, fx, fy, fz, n_objects.
        """
-        self._require_usable()
        self.field.update_params(**kwargs)

    # -- Snapshots -----------------------------------------------------------
    @context_bound
    def snapshot(self):
        """Snapshot the flow field; restore keeps the current clock and controls."""
-        self._require_usable()
        self.field.snapshot(step_id=self.stepper.step_count)

    @context_bound
    def restore(self):
        """Restore the saved flow field at the current streaming parity."""
-        self._require_usable()
        self.field.restore(step_id=self.stepper.step_count)

    # -- Checkpoint / Restore (HDF5) ----------------------------------------
    @context_bound
    def save_checkpoint(self, path: str = None):
        """Save full simulation state to an HDF5 file."""
-        self._require_usable()
        from .common.checkpoint import save_checkpoint
-        self._reject_moving_bodies("save_checkpoint()")
        if self.bodies.jets:
            raise NotImplementedError("Jets are not checkpointed yet")
        return save_checkpoint(self.field, self.stepper, self.lbm_cfg,
@@ -889,9 +682,7 @@ class Simulation:
    @context_bound
    def load_checkpoint(self, path: str):
        """Restore simulation state from an HDF5 checkpoint."""
-        self._require_usable()
        from .common.checkpoint import load_checkpoint
-        self._reject_moving_bodies("load_checkpoint()")
        if not self._initialized:
            self.initialize()
        load_checkpoint(path, self.field, self.stepper, self.lbm_cfg,
@@ -910,12 +701,13 @@ class Simulation:
                cuda.Context.synchronize()
                # Release owned GPU resources while their context is current.
                self.stepper = None
-                self._moving_tables = None
                self.bodies = None
                self.field = None
                self._module = None
                self._stream = None
            ctx.close()
+        compiler.cleanup_build_dir(getattr(self, "_build_dir", None))
+        self._build_dir = None
        self._closed = True

    def __enter__(self):
@@ -1,66 +0,0 @@
-"""Checkpoint save -> load round trip for a scene with passive bodies. Requires GPU.
-
-A fresh Simulation with the same scene, restored from the checkpoint must hold the same populations,
-flags, body count and step count, and must stay bitwise identical to the original
-after both continue for the same number of steps. Checkpoints with Jets are
-refused (documented limitation) and are not covered here.
-"""
-
-import os
-import tempfile
-import unittest
-
-import numpy as np
-
-from ._cases import make_sim
-
-# Three separated cylinders (pinball-like); cut-link receivers stay in bulk fluid.
-CIRCLES = (((40, 32), 6), ((56, 22), 6), ((56, 42), 6))
-
-
-def scene():
-    sim = make_sim()
-    sim.initialize()
-    for center, radius in CIRCLES:
-        sim.add_body("circle", center=center, radius=radius)
-    sim.sync_bodies()
-    return sim
-
-
-class CheckpointBodiesGPU(unittest.TestCase):
-    def test_round_trip_is_bitwise_and_continues_identically(self):
-        sim = scene()
-        sim.run(60)
-        with tempfile.NamedTemporaryFile(suffix=".h5", delete=False) as f:
-            path = f.name
-        restored = None
-        try:
-            saved = sim.save_checkpoint(path)
-            # The loader requires the same body count and geometry: rebuild the scene.
-            restored = scene()
-            restored.load_checkpoint(saved)
-
-            self.assertEqual(restored.bodies.count, len(CIRCLES))
-            self.assertEqual(restored.stepper.step_count, sim.stepper.step_count)
-            np.testing.assert_array_equal(restored.get_flags(), sim.get_flags())
-            a, b = sim.get_ddf(), restored.get_ddf()
-            self.assertEqual(a.dtype, b.dtype)
-            self.assertEqual(a.tobytes(), b.tobytes())
-
-            sim.run(40)
-            restored.run(40)
-            self.assertEqual(restored.stepper.step_count, sim.stepper.step_count)
-            a, b = sim.get_ddf(), restored.get_ddf()
-            self.assertTrue(np.isfinite(a).all())
-            self.assertEqual(a.tobytes(), b.tobytes())
-            for i in range(len(CIRCLES)):
-                self.assertTrue(np.all(np.isfinite(restored.read_force(i))))
-        finally:
-            if restored is not None:
-                restored.close()
-            os.unlink(path)
-            sim.close()
-
-
-if __name__ == "__main__":
-    unittest.main()
@@ -1,53 +0,0 @@
-"""Direct Simulation Jet control upload; boundary-law accuracy is tested elsewhere."""
-import numpy as np
-import pycuda.driver as cuda
-
-from CelerisLab.body.jets import Jet, Radial, Sector
-from CelerisLab.lbm.descriptors import FLUID
-from ._cases import make_sim
-
-
-def test_simulation_jet_amplitude_upload_and_continued_steps():
-    # Same grid/circle/sector as the existing uniform surface-actuation fixture.
-    center = (16., 12.)
-    with make_sim(nx=32, ny=24, velocity=0) as sim:
-        sim.add_body("circle", center=center, radius=4.3)
-        index = sim.add_jet(Jet(Sector(center, .7, .85, 4.4),
-                                Radial(center, inward=False), "quartic", .002))
-        sim.initialize()
-        curved = sim.field.curved
-        shape, jet_id = curved.jet_shape.copy(), curved.jet_id.copy()
-        flags = sim.get_flags()
-        driven = jet_id == index
-        assert driven.any() and (~driven).any()
-        velocity_pointer = int(curved.surface_velocity_gpu)
-        previous = None
-        for interval, amplitude in enumerate((.002, -.001)):
-            if interval:
-                count = sim.stepper.step_count
-                sim.set_jet_amplitude(index, amplitude)
-                assert sim.stepper.step_count == count  # update does not step
-            expected = np.zeros_like(curved.surface_velocity)
-            expected[driven] = (amplitude * shape[driven]).astype(np.float32)
-            actual = np.empty_like(expected)
-            with sim.ctx.activate():
-                cuda.memcpy_dtoh(actual, curved.surface_velocity_gpu)
-            np.testing.assert_array_equal(actual, expected)  # actual device column
-            np.testing.assert_array_equal(curved.surface_velocity, expected)
-            assert np.any(actual[driven] != 0)
-            if previous is not None:
-                assert not np.array_equal(actual[driven], previous[driven])
-            previous = actual.copy()
-            assert sim.bodies.jets[index].amplitude == amplitude
-            assert curved.jets[index].amplitude == amplitude
-            assert int(curved.surface_velocity_gpu) == velocity_pointer
-            np.testing.assert_array_equal(curved.jet_shape, shape)
-            np.testing.assert_array_equal(curved.jet_id, jet_id)
-            np.testing.assert_array_equal(sim.get_flags(), flags)
-            sim.run(2)
-            assert sim.stepper.step_count == 2 * (interval + 1)
-            assert sim._failed is None
-            macro = sim.get_macroscopic()
-            fluid = (flags.reshape(24, 32) & FLUID) != 0
-            assert all(np.isfinite(value[fluid]).all() for value in macro.values())
-            assert np.all(macro["rho"][fluid] > 0)
@@ -6,14 +6,14 @@ import pycuda.driver as cuda
 import pytest

 import CelerisLab
-from CelerisLab.cuda import compiler
+from CelerisLab.cuda import compiler_v2
 from ._cases import make_sim


 def test_source_provenance():
    root = Path(__file__).resolve().parents[2] / "src/CelerisLab"
    assert Path(CelerisLab.__file__).resolve().parent == root
-    assert Path(compiler.kernel_path("uniform.cu")).resolve() == root / "lbm/kernels/uniform.cu"
+    assert Path(compiler_v2.kernel_path("kernel_v2.cu")).resolve() == root / "lbm/kernels/kernel_v2.cu"


 def test_two_contexts_interleaved_and_non_lifo_close():
@@ -21,7 +21,7 @@ def test_two_contexts_interleaved_and_non_lifo_close():
    first = make_sim(nx=32, ny=16)
    second = make_sim(nx=48, ny=24, streaming="esopull", shifted=True)
    try:
-        assert first._module is not second._module
+        assert first._build_dir != second._build_dir
        assert cuda.Context.get_current() == before
        first.initialize()
        second.initialize()
@@ -1,62 +0,0 @@
-"""Small serial GPU gates for shared transverse circles; no physical benchmark."""
-import json
-from pathlib import Path
-
-import numpy as np
-
-from CelerisLab import Simulation
-from CelerisLab.body.motion import MovingTables, Translation
-
-CENTRES = ((70., 79.5), (96., 94.5), (96., 64.5))
-
-
-def simulate(tmp_path, *, moving, offsets, reverse=False):
-    config = json.loads((Path(__file__).resolve().parents[2]/'research/steady_pinball/config.json').read_text())
-    config['grid'].update(nx=192, ny=160)
-    p = tmp_path/'config.json'
-    p.write_text(json.dumps(config))
-    with Simulation(str(p)) as sim:
-        envelope = Translation((0., 0., -20., 20.), .5, shared=True)
-        centres = list(reversed(CENTRES)) if reverse else list(CENTRES)
-        ids = [sim.add_body('circle', c, 10., translation=envelope if moving else None) for c in centres]
-        sim.initialize()
-        previous = 0.
-        crossings = 0.
-        for y in offsets:
-            if moving:
-                for bid in ids:
-                    sim.set_body(bid, offset=(0., float(y)), vy=float(y-previous))
-            sim.run(1)
-            if moving:
-                diag = sim.moving_diagnostics()
-                assert np.isfinite(diag).all()
-                assert np.all(diag[:, MovingTables.DIAG.index('no_donor')] == 0)
-                crossings += diag[:, MovingTables.DIAG.index('crossings')].sum()
-            previous = y
-        forces = np.array([sim.read_force(bid) for bid in ids])
-        if reverse:
-            forces = forces[::-1]
-        return sim.get_ddf(), sim.get_flags(), forces, crossings
-
-
-def test_fixed_vs_shared_hold(tmp_path):
-    fixed = simulate(tmp_path, moving=False, offsets=[0.]*32)
-    held = simulate(tmp_path, moving=True, offsets=[0.]*32)
-    assert np.array_equal(fixed[0], held[0], equal_nan=True)
-    assert np.array_equal(fixed[1], held[1])
-    # FP32 atomic force reduction order only; populations remain exactly equal.
-    np.testing.assert_allclose(fixed[2], held[2], rtol=0., atol=1e-4)
-    assert held[3] == 0
-
-
-def test_common_motion_member_order_has_no_population_effect(tmp_path):
-    # MAX_STEP=.5 is a geometric bound, not a low-Mach stability guarantee.
-    # Keep the complete +/-D excursion at wall speed .01, equal to mean inflow.
-    offsets = np.concatenate((np.arange(1, 2001), np.arange(1999, -2001, -1),
-                              np.arange(-1999, 1))) * .01
-    forward = simulate(tmp_path, moving=True, offsets=offsets)
-    reverse = simulate(tmp_path, moving=True, offsets=offsets, reverse=True)
-    assert forward[3] > 0 and forward[3] == reverse[3]
-    assert np.array_equal(forward[0], reverse[0], equal_nan=True)
-    assert np.array_equal(forward[1], reverse[1])
-    np.testing.assert_allclose(forward[2], reverse[2], rtol=0., atol=1e-4)
@@ -16,7 +16,6 @@
 #define NZ 1
 #define NT 1
 #define COLLISION_MODEL 0
-#define BLOCK_ROOT_BC 2
 #define USE_LES 0
 #define RHO 1.f
 #define U0 .025f
@@ -41,8 +40,7 @@ inline float __fdiv_rn(float a,float b){return a/b;}
 #include "boundary/inlet_outlet.cuh"
 #include "step/one_step_double.cu"
 #else
-#include "core/cell_kind.cuh"
-#include "operators/block_collision.cuh"
+constexpr unsigned char KIND_OUTER=2;
 #include "step/block_channel.cu"
 #endif
 int main(){
@@ -1,46 +0,0 @@
-"""Check historical source manifests against their own recorded commit, not today's checkout."""
-
-import io
-from pathlib import Path
-import subprocess
-import tarfile
-
-ROOT = Path(__file__).resolve().parents[2]
-
-
-def _require(commit):
-    """Missing recorded history is an explicit failure, never a skip or a repin."""
-    found = subprocess.run(
-        ["git", "-C", str(ROOT), "cat-file", "-e", commit + "^{commit}"],
-        capture_output=True,
-    )
-    if found.returncode:
-        raise AssertionError(
-            f"Required history missing: commit {commit} is not in this clone; "
-            "fetch it instead of repinning or substituting"
-        )
-
-
-def tracked(commit, prefix="src"):
-    """Tracked paths under prefix at the recorded commit."""
-    _require(commit)
-    return set(
-        subprocess.check_output(
-            ["git", "-C", str(ROOT), "ls-tree", "-r", "--name-only", commit, prefix],
-            text=True,
-        ).splitlines()
-    )
-
-
-def historical_tree(commit, dest):
-    """Extract the tracked tree of the recorded commit into dest."""
-    _require(commit)
-    archive = subprocess.check_output(
-        ["git", "-C", str(ROOT), "archive", "--format=tar", commit]
-    )
-    dest = Path(dest)
-    dest.mkdir(parents=True, exist_ok=True)
-    extra = {"filter": "data"} if hasattr(tarfile, "data_filter") else {}
-    with tarfile.open(fileobj=io.BytesIO(archive)) as tar:
-        tar.extractall(dest, **extra)
-    return dest
@@ -83,32 +83,6 @@ assert abs(sum(compute_feq_d2q9(1.,0.,0.)) - 1.) < 1e-6


 class BuildContracts(unittest.TestCase):
-    def test_block_root_modes_are_rendered_and_recorded(self):
-        with tempfile.TemporaryDirectory() as root:
-            for mode in (0, 1, 2):
-                with self.subTest(mode=mode):
-                    build = compiler.generate_config(LBMConfig(), build_root=root, block_root_bc=mode)
-                    try:
-                        method = Path(build, "config/config_method.h").read_text()
-                        self.assertIn(f"#define BLOCK_ROOT_BC {mode}\n", method)
-                        metadata = json.loads(Path(build, ".celeris-build").read_text())
-                        self.assertEqual(metadata["block_root_bc"], mode)
-                        self.assertNotIn("block_root_bc", metadata["config"])
-                    finally:
-                        compiler.cleanup_build_dir(build)
-            build = compiler.generate_config(LBMConfig(), build_root=root)
-            try:
-                self.assertEqual(json.loads(Path(build, ".celeris-build").read_text())["block_root_bc"], 0)
-            finally:
-                compiler.cleanup_build_dir(build)
-
-    def test_invalid_block_root_mode_fails_before_snapshot(self):
-        for mode in (-1, 3, True, False, 1.0, "1", None):
-            with self.subTest(mode=mode), patch.object(compiler.tempfile, "mkdtemp") as allocate:
-                with self.assertRaisesRegex(ValueError, "block_root_bc"):
-                    compiler.generate_config(LBMConfig(), block_root_bc=mode)
-                allocate.assert_not_called()
-
    @staticmethod
    def fake_compile(command, check):
        source = Path(command[-3])
@@ -126,7 +100,8 @@ class BuildContracts(unittest.TestCase):
            def work(nx, count):
                build = compiler.generate_config(LBMConfig(nx=nx), count, build_root=root)
                barrier.wait()
-                output = compiler.compile_kernel(build_dir=build)
+                # Compatibility form is context-local even without explicit path.
+                output = compiler.compile_kernel()
                data = json.loads(Path(output).read_text())
                self.assertEqual(data, {"nx": nx, "objects": count})
                metadata = json.loads(Path(output + ".json").read_text())
@@ -155,7 +130,7 @@ class BuildContracts(unittest.TestCase):
            compiler.cleanup_build_dir(a)
            compiler.cleanup_build_dir(b)
            with self.assertRaises(RuntimeError):
-                compiler.compile_kernel(build_dir=a)  # removed snapshot is never compiled
+                compiler.compile_kernel()

    def test_failed_compile_cannot_implicitly_load_previous_artifact(self):
        with tempfile.TemporaryDirectory() as root:
@@ -168,7 +143,8 @@ class BuildContracts(unittest.TestCase):
                with self.assertRaises(subprocess.CalledProcessError):
                    compiler.compile_kernel(build_dir=build)
            self.assertEqual(Path(previous).read_bytes(), old_bytes)
-            self.assertEqual(sorted(Path(build).glob("uniform-*.ptx")), [])  # no partial output
+            with self.assertRaisesRegex(RuntimeError, "No compiled PTX"):
+                compiler.load_module()
            compiler.cleanup_build_dir(build)


@@ -7,7 +7,7 @@ from CelerisLab.config import LBMConfig
 from CelerisLab.lbm.blocks import BlockLayout2D
 from CelerisLab.lbm.channel import channel_masks, validate_channel_config, validate_channel_transfers
 from CelerisLab.lbm.refinement import FixedPatch2D
-from CelerisLab.lbm.refinement_tables import blocked_coarse_tables
+from CelerisLab.lbm.refinement_tables import blocked_base_tables
 from .test_numerical_operators import compile_run


@@ -31,7 +31,7 @@ def transfer(bounds, block=(4, 6)):
    cfg = LBMConfig(nx=24, ny=20, viscosity=.1)
    pair = FixedPatch2D.from_config(cfg, bounds)
    layout = BlockLayout2D.build(20, 24, *block)
-    targets = blocked_coarse_tables(pair, layout, np.argsort(pair.coalesce_coarse))[1]
+    targets = blocked_base_tables(pair, layout, np.argsort(pair.coalesce_coarse))[1]
    return pair, layout, targets


@@ -50,7 +50,7 @@ def test_masks_and_minimal_footprint():
 def test_actual_closure_read_conflicts():
    pair, layout, targets = transfer((6, 6, 18, 14))
    validate_channel_transfers(pair, layout, targets)
-    for target in (layout.slot(int(layout.owner[5, -1]) - 1, 2),  # integer under NumPy 1 and 2
+    for target in (layout.slot(layout.owner[5, -1]-1, 2),
                   layout.slot(layout.owner[1, 4], 4),
                   layout.slot(layout.owner[-2, 4], 3)):
        with pytest.raises(ValueError, match="immutable"):
@@ -74,14 +74,14 @@ def test_evolved_ghost_snapshot_and_physical_download():
    from .test_refinement_three_level_multipatch import host_module
    host = host_module()
    storage = {}
-    host.compiler.build_module.return_value.get_global.side_effect = lambda name: (name, 12 if name == "d_block_channel" else 20)
+    host.compiler.load_module.return_value.get_global.side_effect = lambda name: (name, 12 if name == "d_block_channel" else 20)
    host.cuda.mem_alloc.side_effect = lambda size: Mock()
    host.cuda.memcpy_htod.side_effect = lambda ptr, a: storage.__setitem__(id(ptr), np.array(a, copy=True))
    host.cuda.memcpy_dtoh.side_effect = lambda a, ptr: np.copyto(a, storage[id(ptr)])
    context = Mock(activate=nullcontext, sm_arch="sm_70")
    cfg = LBMConfig(nx=24, ny=20, viscosity=.1, velocity=.025)
-    backend = host.FixedPatchStepper(cfg, context=context, coarse_boundary="channel",
-                                    refinements=[(6, 6, 18, 14)], level_blocks=[(4, 6), (4, 4)])
+    backend = host.FixedPatchStepper(cfg, (6, 6, 18, 14), context=context,
+                                    coarse_boundary="channel", base_block=(4, 6), fine_block=(4, 4))
    try:
        weights = np.array([4/9]+[1/9]*4+[1/36]*4)[:, None, None]
        arrays = [np.broadcast_to(weights, level.shape).copy() for level in backend._levels]
@@ -96,7 +96,6 @@ def test_evolved_ghost_snapshot_and_physical_download():
        arrays[0][0, 0, 0] = np.nan
        with pytest.raises(ValueError, match="finite"):
            backend.initialize(*arrays)
-        assert backend._levels[0].kernel == host.compiler.build_module.return_value.get_function("BlockChannelStep")
-        assert [call.kwargs["block_root_bc"] for call in host.compiler.build_module.call_args_list] == [2, 0]
+        assert backend._levels[0].kernel == host.compiler.load_module.return_value.get_function("BlockChannelStep")
    finally:
        backend.close()
@@ -1,148 +0,0 @@
-"""Research video contracts: continuous state and display-only sampling."""
-import importlib.util
-import json
-from pathlib import Path
-from types import SimpleNamespace
-
-import numpy as np
-import pytest
-
-ROOT=Path(__file__).resolve().parents[2]
-spec=importlib.util.spec_from_file_location('continuous_viv_video_driver',ROOT/'research/continuous_viv/run.py')
-m=importlib.util.module_from_spec(spec)
-spec.loader.exec_module(m)
-from research.continuous_viv import render as r
-
-
-def test_physical_zero_and_independent_steady_control():
-    model=SimpleNamespace(predict=lambda *a,**k:pytest.fail('steady/OFF must not invoke PPO'))
-    for scene in ('steady','karman'):
-        for phase in ('off_before','off_after'):
-            target,action=m.command(scene,phase,None,model)
-            np.testing.assert_array_equal(target,[0,0,0])
-            np.testing.assert_array_equal(m.base.wall_target(action,2),target)
-    target,action=m.command('steady','on',None,model)
-    np.testing.assert_array_equal(target,np.array([0,-5.1,5.1])*.005)
-    assert np.isnan(action).all()
-
-
-@pytest.mark.parametrize('bad',[[2,0,0],[np.nan,0,0],[0,0]])
-def test_invalid_policy_output(bad):
-    model=SimpleNamespace(predict=lambda *a,**k:(bad,None))
-    with pytest.raises(RuntimeError,match='invalid PPO'):
-        m.command('karman','on',np.zeros(12),model)
-
-
-def test_continuous_switches_previous_observation_and_native_rhs(tmp_path):
-    from CelerisLab.body.motion import MovingTables
-    calls,forces,seen,frames=[],[],[],[]
-    class Structure:
-        y=v=0.;mass=2.;stiffness=3.;frequency=.1
-        def candidate(self,f):
-            forces.append(f)
-            return self.y+.001,self.v+.002
-    class Sim:
-        stepper=SimpleNamespace(step_count=100)
-        n=0
-        def set_body(self,p,**kw):calls.append((p,kw))
-        def run(self,n,**kw):
-            assert n==1 and kw==dict(zero_obs=True,sync_obs=True)
-            self.n+=1;self.stepper.step_count+=1
-        def moving_diagnostics(self):
-            d=np.zeros((3,len(MovingTables.DIAG)),np.float32)
-            d[:,MovingTables.DIAG.index('cme_y')]=self.n
-            d[:,MovingTables.DIAG.index('wen_y')]=10*self.n
-            d[:,MovingTables.DIAG.index('cover_jy')]=1000
-            return d
-        def read_force(self,p):return [0.,float(self.n),0.]
-        def read_sensor(self,p):return [.001,0.,0.]
-    model=SimpleNamespace(predict=lambda obs,**kw:(seen.append(obs.copy()) or np.ones(3)*.1,None))
-    norm=dict(force_norm_fact=100.,sens_deviation=np.zeros(6),sens_norm_fact=np.ones(6))
-    sim,structure=Sim(),Structure()
-    def render(sim,step,phase,eff,rows):
-        if step%3==0:frames.append((step,sim.stepper.step_count,eff.copy()))
-    m.evolve(sim,[1,2,3],[4,5,6],structure,7.,scene='karman',model=model,norm=norm,
-             intervals=2,si=2,out=tmp_path,render=render,start=m.time.monotonic(),wall_cap=60)
-    assert sim.n==12 and sim.stepper.step_count==112
-    assert forces==[7.,*list(33.*np.arange(1,12))]  # no reset, SI averaging, or node impulse in RHS
-    rows=np.load(tmp_path/'steps.npy')
-    np.testing.assert_allclose(rows[:,1],.001*np.arange(1,13))
-    np.testing.assert_allclose(rows[:,2],.002*np.arange(1,13))
-    np.testing.assert_array_equal(rows[:4,15:],0)
-    np.testing.assert_array_equal(rows[8:,15:],0)
-    np.testing.assert_array_equal(rows[4,15:],rows[6,15:])  # per-SI EMA reset, not per-frame
-    signals=json.loads((tmp_path/'signals.json').read_text())
-    np.testing.assert_array_equal(seen[0],np.asarray(signals[1]['observation'],np.float32))
-    np.testing.assert_array_equal(seen[1],np.asarray(signals[2]['observation'],np.float32))
-    assert len(seen)==2 and seen[0].any()
-    report=json.loads((tmp_path/'report.json').read_text())
-    assert [x['absolute_clock'] for x in report['switches']]==[100,104,108]
-    assert [x['previous_rhs'] for x in report['switches']]==[7.,132.,264.]
-    np.testing.assert_allclose([x['y'] for x in report['switches']],[0,.004,.008])
-    assert [x[0] for x in frames]==[3,6,9,12]
-    assert all(x[1]==100+x[0] for x in frames)
-    assert len(calls)==36 and all(c[1]['vy']==pytest.approx(.001) for c in calls)
-
-
-def test_gear_schedule_and_complete_phase_endpoints():
-    n=1280000
-    schedule=r.video_schedule(n)
-    times=list(schedule)
-    assert times==sorted(set(times)) and times[-1]==3*n
-    assert all(p*n in schedule for p in (1,2,3))
-    assert set(schedule.values())=={1,2,5,10}
-    assert all(speed==1 for step,speed in schedule.items() if step%n>n//2)
-    part=r.frame_schedule(n//2,800,True)
-    assert [s for _,s in part[:15]]==[1]*15
-    assert [s for _,s in part[15:30]]==[2]*15
-    assert [s for _,s in part[-15:]]==[1]*15
-    assert part[-1][0]==n//2
-
-
-def test_smoke_schedule_covers_all_switches():
-    schedule=r.video_schedule(32,True)
-    assert list(schedule)==list(range(8,97,8))
-    assert set(schedule.values())=={1}
-
-
-def test_vorticity_sign_scale_and_solid_stencil_mask():
-    y,x=np.mgrid[:9,:11]
-    ux=-.0001*y;uy=.0001*x
-    flags=np.ones(x.shape,np.uint16)
-    omega=r.vorticity(ux,uy,flags)
-    np.testing.assert_allclose(omega[1:-1,1:-1],.0002*40/.005)
-    assert np.isnan(omega[0]).all()
-    flags[4,5]=2
-    omega=r.vorticity(ux,uy,flags)
-    for yy,xx in ((4,5),(3,5),(5,5),(4,4),(4,6)):
-        assert np.isnan(omega[yy,xx])
-    assert np.isfinite(omega[3,4])
-
-
-def test_fixed_inset_coordinate_and_no_motion_gain():
-    a=np.array(r.pixel(30,0,r.INSET,r.INSET_LIMITS))
-    b=np.array(r.pixel(30,1,r.INSET,r.INSET_LIMITS))
-    c=np.array(r.pixel(31,0,r.INSET,r.INSET_LIMITS))
-    assert b[0]==a[0] and a[1]-b[1]==56
-    assert c[0]-a[0]==56
-    assert r.pixel(r.INSET_LIMITS[0],r.INSET_LIMITS[3],r.INSET,r.INSET_LIMITS)==r.INSET[:2]
-
-
-def test_config_real_loader_and_structure_unchanged(tmp_path):
-    from CelerisLab.config import load_lbm_config
-    p=tmp_path/'config.json';p.write_text(json.dumps(m.base.config(40)))
-    cfg=load_lbm_config(str(p));cfg.validate()
-    assert (cfg.nx,cfg.ny,cfg.velocity,cfg.viscosity)==(2559,1022,.005,.004)
-    s=m.base.Structure(4.,2.5e-5,0.,40.)
-    assert s.mass==pytest.approx(15079.644737231007)
-    assert s.stiffness==pytest.approx(.00037207532016359776)
-    assert s.damping==0 and s.frequency*40/.005==.2
-
-
-def test_scene_timing_keeps_actual_legacy_intervals_and_same_physical_duration():
-    assert m.timing('steady',False)==(320,4000,2048000)
-    assert m.timing('karman',False)==(400,3200,2048000)
-    for scene in ('steady','karman'):
-        n,si,warm=m.timing(scene,False)
-        assert n*si*.005/40==160
-        assert m.timing(scene,True)==(1,32,32)
@@ -1,79 +0,0 @@
-"""CPU-only contract tests for run_dfg_re20. Not CUDA or DFG acceptance evidence."""
-
-import sys
-from pathlib import Path
-import unittest
-
-sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "validation"))
-import run_dfg_re20 as v  # noqa: E402
-import run_refined_dfg as rr  # noqa: E402
-
-h, _ = rr.helpers(rr.DEFAULT_SOURCE)
-
-
-def rows(values, tstar_end=v.TSTAR_MAX):
-    n = int(round(tstar_end / v.SAMPLE_TSTAR))
-    return [dict(tstar=(i + 1) * v.SAMPLE_TSTAR, **values(i)) for i in range(n)]
-
-
-class Re20Contract(unittest.TestCase):
-    def test_lattice_parameters_and_bounds(self):
-        root, uniform = v.lattice_parameters(40), v.lattice_parameters(80)
-        self.assertAlmostEqual(root["tau"], 0.56, places=12)
-        self.assertAlmostEqual(uniform["tau"], 0.62, places=12)
-        self.assertEqual((root["steps"], root["interval"]), (240000, 2000))
-        self.assertEqual((uniform["steps"], uniform["interval"]), (480000, 4000))
-        self.assertAlmostEqual(v.plan()["refined_fine_tau"], 0.62, places=12)
-
-    def test_config_only_changes_viscosity(self):
-        base = v._re100_config(h, 40, "SRT", "none")
-        cfg, body, p = v.config(h, 40, "SRT")
-        self.assertAlmostEqual(cfg["physics"]["viscosity"], 0.01 * 40 / 20, places=15)
-        self.assertEqual((p["re"], p["viscosity"]), (20.0, cfg["physics"]["viscosity"]))
-        base[0]["physics"]["viscosity"] = cfg["physics"]["viscosity"]
-        self.assertEqual(base[0], cfg)
-        self.assertEqual(base[1], body)
-        with self.assertRaisesRegex(ValueError, "no Jets"):
-            v.config(h, 40, "MRT", "zero")
-
-    def test_units(self):
-        s = v.sample([2.0, -0.5], 4, 40, 3.0)
-        den = rr.SPEED**2 * 40 / 2
-        self.assertAlmostEqual(s["cd"], 2.0 / 4 / den)
-        self.assertAlmostEqual(s["cl"], -0.5 / 4 / den)
-        self.assertAlmostEqual(s["p_diff"], 3.0 * 0.04)
-        self.assertEqual(s["dp_scaled"], 3.0)
-
-    def test_steady_and_verdict(self):
-        inside = dict(cd=5.58, cl=0.0106, p_diff=0.1174)
-        out = v.summarize(rows(lambda i: inside))
-        self.assertEqual((out["status"], out["steady"], out["window_samples"]),
-                         ("WITHIN_INTERVALS", True, 21))
-        self.assertTrue(out["cd_positive"])
-        self.assertAlmostEqual(out["edge_distance"]["cl"], 0.0002)
-        self.assertTrue(all(out["verdict"].values()))
-        low = v.summarize(rows(lambda i: dict(inside, cl=0.0100)))
-        self.assertEqual(low["status"], "OUTSIDE_INTERVALS")
-        self.assertFalse(low["verdict"]["cl"])
-
-    def test_slow_drift_gives_no_verdict(self):
-        # Range 2e-5 passes (limit 6e-5); slope * window 2e-5 exceeds 1.2e-5.
-        out = v.summarize(rows(lambda i: dict(cd=5.58, cl=0.0106 + 1e-6 * i, p_diff=0.1174)))
-        self.assertEqual((out["status"], out["verdict"]), ("NOT_STEADY", None))
-        self.assertLessEqual(out["ranges"]["cl"], out["range_limits"]["cl"])
-        self.assertGreater(out["drifts"]["cl"], out["slope_limits"]["cl"])
-
-    def test_noise_range(self):
-        quiet = v.summarize(rows(lambda i: dict(cd=5.58, cl=0.0106 + 2e-5 * (i % 2), p_diff=0.1174)))
-        self.assertTrue(quiet["steady"])  # within the range limit, no trend
-        noisy = v.summarize(rows(lambda i: dict(cd=5.58, cl=0.0106 + 1e-4 * (i % 2), p_diff=0.1174)))
-        self.assertEqual(noisy["status"], "NOT_STEADY")
-        self.assertGreater(noisy["ranges"]["cl"], noisy["range_limits"]["cl"])
-
-    def test_incomplete_run_gives_no_verdict(self):
-        out = v.summarize(rows(lambda i: dict(cd=5.58, cl=0.0106, p_diff=0.1174), tstar_end=30))
-        self.assertEqual((out["status"], out["verdict"]), ("INCOMPLETE", None))
-
-
-if __name__ == "__main__":
-    unittest.main()
@@ -1,223 +0,0 @@
-"""CPU tests of the Dütsch protocol arithmetic (docs/validation/duetsch_re100_kc5_protocol.md §6a)."""
-import importlib.util
-import math
-from pathlib import Path
-
-import numpy as np
-import pytest
-
-_spec = importlib.util.spec_from_file_location(
-    "duetsch_protocol", Path(__file__).resolve().parents[2] / "research/duetsch_re100_kc5/protocol.py")
-p = importlib.util.module_from_spec(_spec)
-_spec.loader.exec_module(p)
-
-def _load(rel, name):
-    """Load a research driver module under a unique name (no bare ``import run``)."""
-    import sys
-    path = Path(__file__).resolve().parents[2] / rel
-    sys.path.insert(0, str(path.parent))  # for the driver's own sibling imports
-    try:
-        spec = importlib.util.spec_from_file_location(name, path)
-        mod = importlib.util.module_from_spec(spec)
-        spec.loader.exec_module(mod)
-    finally:
-        sys.path.remove(str(path.parent))
-    return mod
-
-
-T = 2520
-
-
-def test_phase_and_cycle_bookkeeping():
-    assert p.phase(0, T) == 270.0 and p.cycle(0, T) == 0          # +A, at rest, phi = -90
-    assert p.phase(T // 4, T) == 0.0 and p.cycle(T // 4, T) == 1  # mean position, u = -U_max
-    assert p.position(0, T, 1.0) == 1.0
-    assert p.cycle(T // 4 - 1, T) == 0 and p.cycle(T // 4 + T - 1, T) == 1
-    assert p.cycle(T // 4 + T, T) == 2
-    assert p.phase(T // 6, T) == pytest.approx(330.0) and p.cycle(T // 6, T) == 0  # startup quarter
-    assert p.phase(7 * T // 6, T) == pytest.approx(330.0) and p.cycle(7 * T // 6, T) == 1
-    for ph, frac in ((180.0, .75), (210.0, 5 / 6)):
-        s = round(frac * T) + T
-        assert p.phase(s, T) == pytest.approx(ph) and p.bin_phase(s, T) == ph
-    assert p.bin_phase(round(.75 * T) + T - 1, T) is None
-    assert sum(p.bin_phase(s, T) == 180.0 for s in range(T, 2 * T)) == T // 360
-
-
-def test_settling_and_common_window():
-    passes = {k: True for k in range(3, 12)}
-    assert p.settled_start(passes) == 7                          # pairs 3->4, 4->5, 5->6
-    late = {**passes, 5: False}
-    assert p.settled_start(late) == 9                            # pairs 6->7, 7->8, 8->9
-    assert p.common_window([7, 9], [passes, passes]) == (9, 10, 11)
-    assert p.common_window([7, 10], [passes, passes]) is None    # K + 2 = 12 beyond the cap
-    assert p.common_window([7, None], [passes, passes]) is None
-    assert p.common_window([7, 7], [passes, {**passes, 8: False}]) is None  # must stay settled
-    # a case settled early must keep passing while waiting for the common K
-    assert p.common_window([7, 9], [{**passes, 8: False}, passes]) is None
-    long = {k: True for k in range(3, 32)}
-    assert p.common_window([10], [long]) is None                 # default cap 11
-    assert p.common_window([29], [long], last_scored=31) == (29, 30, 31)
-    assert p.common_window([30], [long], last_scored=31) is None
-
-
-def test_solid_aware_bilinear():
-    field = np.arange(16.0).reshape(4, 4)
-    fluid = np.ones((4, 4), bool)
-    value, used, total = p.bilinear_fluid(field, fluid, 1.25, 1.5)
-    assert total == pytest.approx(1.0) and value == pytest.approx(0.75 * 0.5 * (5 + 9) + 0.25 * 0.5 * (6 + 10))
-    fluid[1, 1] = False                                           # one solid corner
-    value, used, total = p.bilinear_fluid(field, fluid, 1.25, 1.5)
-    assert total == pytest.approx(1.0 - 0.75 * 0.5)
-    assert all(not (i == 1 and j == 1) for i, j, _ in used)
-    assert sum(w for *_, w in used) == pytest.approx(1.0)
-    fluid[:] = False
-    assert p.bilinear_fluid(field, fluid, 1.25, 1.5) == (None, (), 0.0)
-
-
-def test_interval_bases_and_morison_fit_recover_known_coefficients():
-    b = np.array([p.interval_bases(n, T) for n in range(T // 4, T // 4 + 3 * T)])
-    phi = 2 * np.pi * (np.arange(T // 4, T // 4 + 3 * T) + .5) / T - np.pi / 2
-    assert np.allclose(b[:, 1], np.sin(phi), atol=1e-5)          # midpoint ~ interval mean
-    f = 2.09 * b[:, 0] - (math.pi ** 2 * 1.45 / p.KC) * b[:, 1]
-    assert p.morison_fit(f, b[:, 0], b[:, 1]) == pytest.approx((2.09, 1.45), abs=1e-9)
-
-
-def test_quadrature_rule_reused_across_steps_and_periods(monkeypatch):
-    original = np.polynomial.legendre.leggauss
-    orders = []
-
-    def counted(points):
-        orders.append(points)
-        return original(points)
-
-    p._quadrature_rule.cache_clear()
-    monkeypatch.setattr(np.polynomial.legendre, "leggauss", counted)
-    try:
-        for points in (16, 8, 16):
-            for period in (T, 2 * T):
-                for n in (0, 123, period + 123):
-                    p.interval_bases(n, period, points)
-        assert orders == [16, 8]
-    finally:
-        p._quadrature_rule.cache_clear()
-
-
-def test_interval_sine_basis_matches_exact_integral():
-    for period in (T, 2 * T):
-        half_width = math.pi / period
-        for n in (0, period // 4, period // 2, period - 1, 7 * period + 123):
-            midpoint = 2 * math.pi * ((n % period) + .5) / period - math.pi / 2
-            expected = math.sin(midpoint) * math.sin(half_width) / half_width
-            assert p.interval_bases(n, period)[1] == pytest.approx(expected, rel=0, abs=2e-15)
-
-
-def test_geometry_repeats_exactly_across_cycles():
-    A = p.amplitude(20)
-    for m in (0, 1, T // 4, T // 2 - 1, 7 * T // 12):
-        for c in (1, 5, 11):
-            assert p.position(m + c * T, T, A) == p.position(m, T, A)
-            assert p.phase(m + c * T, T) == p.phase(m, T)
-            v0 = p.position(m + 1, T, A) - p.position(m, T, A)
-            assert p.position(m + 1 + c * T, T, A) - p.position(m + c * T, T, A) == v0
-    assert p.cycle(T // 4 + 5 * T, T) == 6  # unwrapped index stays separate
-    assert p.interval_bases(123 + 7 * T, T) == p.interval_bases(123, T)
-
-
-def test_exact_point_inside_body_is_missing_even_with_fluid_corners():
-    field = np.zeros((6, 6))
-    fluid = np.ones((6, 6), bool)
-    fluid[3, 3] = False                         # only one corner solid
-    centre, radius = (3.0, 3.0), 0.3
-    value, used, total = p.sample(field, fluid, 3.2, 3.1, centre, radius)   # inside the circle
-    assert value is None and used == () and total == 0.0
-    value, used, total = p.sample(field, fluid, 3.35, 3.0, centre, radius)  # just outside
-    assert value is not None and total > 0.0
-
-
-def test_generated_config_passes_the_real_loader(tmp_path):
-    import json
-    run = _load("research/duetsch_re100_kc5/run.py", "duetsch_run")
-    from CelerisLab.config import load_lbm_config
-    cfg_dict, u_max, n = run.config(20, 10.0, 2520)
-    path = tmp_path / "config_lbm.json"
-    path.write_text(json.dumps(cfg_dict))
-    cfg = load_lbm_config(str(path))
-    assert (cfg.nx, cfg.ny) == (n, n) == (200, 200)
-    assert cfg.collision == "MRT" and cfg.streaming == "double_buffer" and not cfg.ddf_shifting
-    assert cfg.velocity == 0.0 and cfg.viscosity == pytest.approx(u_max * 20 / 100)
-    assert cfg.y_wall_bc == "bounce_back"
-
-
-def _analyze():
-    return _load("research/duetsch_re100_kc5/analyze.py", "duetsch_analyze")
-
-
-def test_hf_energy_is_parseval_weighted():
-    a = _analyze()
-    n = 360
-    t = np.arange(n)
-    x = 1.0 + np.cos(2 * np.pi * 5 * t / n) + 2.0 * np.cos(2 * np.pi * 30 * t / n) + 0.5 * np.cos(np.pi * t)
-    e = a.one_sided_energy(np.fft.rfft(x), n) / n
-    assert e.sum() == pytest.approx(np.sum(x ** 2))               # Parseval
-    expected = (2.0 ** 2 / 2 + 0.5 ** 2) / np.mean(x ** 2)       # bins >= 21 (30 and Nyquist)
-    assert e[21:].sum() / e.sum() == pytest.approx(expected)
-
-
-def test_horizon_excludes_future_coverage_and_events(monkeypatch):
-    a = _analyze()
-    T, horizon = 360, 4
-    steps = round((0.25 + 6) * T)                                 # cycles 1..6 recorded
-    diag = np.zeros((steps, 15))
-    diag[round((0.25 + horizon) * T):, 13] = 1.0                  # synthetic future no_donor
-    rows = [(s, p.cycle(s, T), 180.0, 0.0, 0.0, 0.1, 0.0, 1.0) for s in range(steps)
-            if p.bin_phase(s, T) is not None and p.cycle(s, T) > p.DISCARD]
-    case = dict(path="c", D=20, T=T, box=10, n=200, u_max=.04, nu=.008, tau=.524, A=1.0,
-                steps=steps, cycles=6, F_ref=1.0, force=np.zeros((steps, 2)), diag=diag,
-                samples=np.asarray(rows, float))
-    monkeypatch.setattr(a, "load", lambda path: case)
-    out = []
-    monkeypatch.setattr("builtins.print", lambda text: out.append(text))
-    a.main(["c", "--horizon", str(horizon)])
-    import json
-    entry = json.loads(out[0])["cases"][0]
-    assert sorted(int(k) for k in entry["coverage"]) == [3, 4]   # nothing from cycles 5, 6
-    assert entry["no_donor"] == 0.0
-
-
-
-def _capture():
-    spec = importlib.util.spec_from_file_location(
-        "duetsch_capture", Path(__file__).resolve().parents[2] / "research/duetsch_re100_kc5/capture.py")
-    mod = importlib.util.module_from_spec(spec)
-    spec.loader.exec_module(mod)
-    return mod
-
-
-def test_capture_crop_downsample_and_trends():
-    c = _capture()
-    n, D = 2400, 40
-    xm = ym = 0.5 * (n - 1)
-    A, R = p.amplitude(D), 20.0
-    box = c.crop_box(xm, ym, D, n, (xm - A - R, xm + A + R, ym - R, ym + R))
-    assert box == (880, 1520, 960, 1440) and box[1] - box[0] + 1 == 641 and box[3] - box[2] + 1 == 481
-    with pytest.raises(ValueError):
-        c.crop_box(xm, ym, D, 600, (0, 1, 0, 1))                    # leaves the domain
-    with pytest.raises(ValueError):
-        c.crop_box(xm, ym, D, n, (xm - 9 * D, xm, ym, ym))           # clips the swept body
-    field = np.arange(64.0).reshape(8, 8)
-    fluid = np.ones((8, 8), bool)
-    fluid[:4, :4] = False
-    down = c.downsample(field, fluid, 4)
-    assert np.isnan(down[0, 0]) and down[1, 1] == field[4:, 4:].mean()
-    rho = np.ones((n, n)); rho[:, 1:81] = 1.01
-    row = c.trend_row(10, 3, 180.0, rho, np.zeros((n, n)), np.zeros((n, n)),
-                      np.ones((n, n), bool), D, n, box)
-    assert row[7] == pytest.approx(1.01) and row[9] == pytest.approx(1.0)
-
-
-def test_dump_steps_are_the_first_step_of_each_bin():
-    T = 5040
-    for k in (11, 21, 30, 31):
-        starts = [s for s in range(T // 4 + (k - 1) * T, T // 4 + k * T)
-                  if p.bin_phase(s, T) is not None and p.phase(s, T) == p.bin_phase(s, T)]
-        assert len(starts) == 3 and all(p.cycle(s, T) == k for s in starts)
@@ -1,70 +0,0 @@
-"""The public examples run all-blocked: their level tiles must reach the device unchanged.
-
-Host only: a context whose activation raises proves construction (layouts, tables,
-boundary checks) succeeded up to the first CUDA call.
-"""
-import ast
-from dataclasses import replace
-from pathlib import Path
-import unittest
-from unittest.mock import Mock
-
-from CelerisLab.body.geometry.circle import CircleGeometry
-from CelerisLab.body.objects import SimObject
-from CelerisLab.config import LBMConfig
-from CelerisLab.lbm.refinement_stepper import FixedPatchStepper
-
-EXAMPLES = Path(__file__).resolve().parents[2] / "examples"
-
-
-def literal(name, constant):
-    """Module-level literal from an example, read without importing it (no pycuda)."""
-    tree = ast.parse((EXAMPLES / name).read_text())
-    for node in tree.body:
-        if isinstance(node, ast.Assign):
-            for target in node.targets:
-                names = target.elts if isinstance(target, ast.Tuple) else [target]
-                for i, t in enumerate(names):
-                    if isinstance(t, ast.Name) and t.id == constant:
-                        value = node.value.elts[i] if isinstance(target, ast.Tuple) else node.value
-                        return ast.literal_eval(value)
-    raise KeyError(constant)
-
-
-def forbidden():
-    return Mock(activate=Mock(side_effect=AssertionError("CUDA reached")), sm_arch="sm_70")
-
-
-class ExampleTiles(unittest.TestCase):
-    def test_fixed_patch_jet_tiles(self):
-        bounds, blocks = literal("fixed_patch_jet.py", "BOUNDS"), literal("fixed_patch_jet.py", "LEVEL_BLOCKS")
-        width, amplitude = literal("fixed_patch_jet.py", "WIDTH"), literal("fixed_patch_jet.py", "AMPLITUDE")
-        cfg = LBMConfig(nx=48, ny=48, viscosity=.1, velocity=0., wall_slot_width=width,
-                        wall_normal_velocity=amplitude, y_wall_bc="on_site_velocity",
-                        top_wall_bc="reservoir")
-        with self.assertRaisesRegex(AssertionError, "CUDA reached"):
-            FixedPatchStepper(cfg, context=forbidden(), coarse_boundary="slot_reservoir",
-                              refinements=[bounds], level_blocks=[tuple(b) for b in blocks])
-
-    def test_fixed_periodic_patch_tiles(self):
-        with self.assertRaisesRegex(AssertionError, "CUDA reached"):
-            FixedPatchStepper(LBMConfig(nx=16, ny=16, viscosity=.1, velocity=1e-3), context=forbidden(),
-                              refinements=[(4, 4, 12, 12)], level_blocks=[(16, 16), (24, 24)])
-
-    def test_fixed_patch_circle_default_tiles(self):
-        bounds = literal("fixed_patch_circle.py", "BOUNDS")
-        nx, ny = literal("fixed_patch_circle.py", "NX"), literal("fixed_patch_circle.py", "NY")
-        center, radius = literal("fixed_patch_circle.py", "CENTER"), literal("fixed_patch_circle.py", "RADIUS")
-        body = SimObject(0, geometry=CircleGeometry(*center, radius), center=center, radius=radius)
-        periodic = LBMConfig(nx=nx, ny=ny, viscosity=.1)
-        slot = replace(periodic, velocity=0, wall_normal_velocity=.001, wall_slot_width=8,
-                       y_wall_bc="on_site_velocity", top_wall_bc="reservoir")
-        for mode, cfg in (("periodic", periodic), ("slot_reservoir", slot)):
-            with self.subTest(mode=mode), self.assertRaisesRegex(AssertionError, "CUDA reached"):
-                FixedPatchStepper(cfg, context=forbidden(), coarse_boundary=mode,
-                                  refinements=[bounds], level_blocks=[(12, 8), (16, 20)],
-                                  level_objects=[(), (body,)])
-
-
-if __name__ == "__main__":
-    unittest.main()
@@ -8,7 +8,6 @@ import numpy as np
 ROOT = Path(__file__).resolve().parents[2]
 REPO = ROOT
 sys.path.insert(0, str(ROOT / "tests/validation"))
-sys.path.insert(0, str(ROOT / "tests/unit"))
 sys.path.insert(0, str(REPO / "src"))
 from run_jet_circle_cv import (
    CX,
@@ -17,10 +16,8 @@ from run_jet_circle_cv import (
    case,
    state,
    cv,
-    cv_from_macros,
    aperture_probe,
    measured_aperture_flux,
-    PIN,
    verify,
 )

@@ -31,39 +28,6 @@ def eq(rho, u, v):


 class Host(unittest.TestCase):
-    def test_public_macros_pressure_advection_and_cropped_frames(self):
-        for h, origin, shape, rect in (
-            (.5, (0., 0.), (48, 64), (5., 4., 25., 20.)),
-            (.5, (.25, .5), (48, 64), (5.25, 4., 25.25, 20.)),
-            (.25, (.375, .75), (96, 128), (5.125, 4., 25.125, 20.)),
-        ):
-            y, x = np.indices(shape)
-            x = origin[0] + h * (x + .5)
-            k, u, v = 1e-5, .02, -.01
-            rho = 1 + 3 * k * x  # p=(rho-1)/3=k*x
-            ux, uy, fluid = np.full(shape, u), np.full(shape, v), np.ones(shape, bool)
-            result = cv_from_macros(rho, ux, uy, fluid, origin, rect, .004, h)
-            expected = 320 * np.array([3*k*u, k + 3*k*u*u, 3*k*u*v])
-            np.testing.assert_allclose(result[1], expected, rtol=1e-11, atol=1e-13)
-            np.testing.assert_allclose(result, cv(eq(rho, u, v), fluid, origin, rect, .004, h), atol=1e-12)
-            x0, y0, x1, y1 = np.rint((np.array(rect)-np.tile(origin, 2))/h).astype(int)
-            selection = np.s_[y0-2:y1+2, x0-2:x1+2]
-            cropped_origin = np.asarray(origin) + h*np.array([x0-2, y0-2])
-            cropped = cv_from_macros(rho[selection], ux[selection], uy[selection],
-                                    fluid[selection], cropped_origin, rect, .004, h)
-            np.testing.assert_array_equal(cropped, result)
-
-    def test_public_macros_full_normal_viscous_stress(self):
-        y, x = np.indices((48, 64))
-        x = (x + .5) * .5
-        rho, ux, uy, fluid = np.ones_like(x), 1e-4*x*x, np.zeros_like(x), np.ones(x.shape, bool)
-        args = (rho, ux, uy, fluid, (0., 0.), (5., 4., 25., 20.))
-        _, viscous = cv_from_macros(*args, .004)
-        _, inviscid = cv_from_macros(*args, 0.)
-        np.testing.assert_allclose(viscous-inviscid, [0, -4*.004*1e-4*320, 0], atol=1e-13)
-        with self.assertRaisesRegex(ValueError, "matching 2D"):
-            cv_from_macros(rho, ux, uy[:-1], fluid, (0, 0), (5, 4, 25, 20), .004)
-
    def test_descriptor_and_uniform_closed_flux(self):
        from CelerisLab.lbm.descriptors import D2Q9_EX, D2Q9_EY

@@ -168,13 +132,7 @@ class Host(unittest.TestCase):
        self.assertEqual(a["steps"] * 4, b["steps"])

    def test_source_pin(self):
-        from tempfile import TemporaryDirectory
-        from historical_tree import historical_tree
-
-        with self.assertRaisesRegex(RuntimeError, "Source hash mismatch"):
-            verify(REPO)
-        with TemporaryDirectory() as directory:
-            verify(historical_tree(PIN, directory))
+        verify(REPO)


 if __name__ == "__main__":
@@ -1,149 +0,0 @@
-"""Jet amplitude update failure contract (host doubles only, no CUDA numerics).
-
-Both owners validate before any device write, commit host state only after the
-upload returns, and refuse every later call except close() after an uncertain
-device write.
-"""
-from types import SimpleNamespace
-
-import numpy as np
-import pytest
-
-pytest.importorskip("pycuda.driver")
-from CelerisLab import simulation as module
-from CelerisLab.body.jets import Jet, Radial, Sector
-from tests.unit.test_pinned_body_remap import ready
-from tests.unit.test_simulation_lifecycle import make_simulation
-
-BAD = (float("nan"), float("inf"), 1.)
-
-
-class Curved:
-    """Records uploads; ``fail`` raises once the write was attempted."""
-    def __init__(self):
-        self.writes, self.fail = [], False
-
-    def set_jet_amplitude(self, index, amplitude, stream):
-        self.writes.append((index, amplitude))
-        if self.fail:
-            raise RuntimeError("upload failed")
-
-
-def simulation(monkeypatch):
-    sim = make_simulation(monkeypatch)
-    jet = Jet(Sector((6., 5.), 0., .5, 4.), Radial((6., 5.)), "uniform", 1e-3)
-    sim._failed, sim._initialized = None, True
-    sim.bodies, sim.field = SimpleNamespace(jets=[jet]), SimpleNamespace(curved=Curved())
-    return sim, jet
-
-
-def test_simulation_invalid_input_writes_nothing_and_stays_usable(monkeypatch):
-    sim, jet = simulation(monkeypatch)
-    for amplitude in BAD:
-        with pytest.raises(ValueError):
-            sim.set_jet_amplitude(0, amplitude)
-    with pytest.raises(IndexError):
-        sim.set_jet_amplitude(1, 2e-3)
-    assert sim.field.curved.writes == [] and sim.bodies.jets[0] is jet and sim._failed is None
-    sim.set_jet_amplitude(0, 2e-3)  # retry after a rejected input
-    assert sim.field.curved.writes == [(0, 2e-3)] and sim.bodies.jets[0].amplitude == 2e-3
-    sim.close()
-
-
-def test_simulation_upload_failure_keeps_host_and_blocks_reuse(monkeypatch):
-    sim, jet = simulation(monkeypatch)
-    sim.field.curved.fail = True
-    with pytest.raises(RuntimeError, match="upload failed"):
-        sim.set_jet_amplitude(0, 2e-3)
-    assert sim.bodies.jets[0] is jet and sim._failed is not None
-    sim.field.curved.fail = False
-    for call in (lambda: sim.set_jet_amplitude(0, 2e-3), lambda: sim.run(1), sim.step,
-                 sim.sync_bodies, sim.initialize, sim.get_ddf, sim.get_macroscopic,
-                 lambda: sim.read_surface_exchange(0), lambda: sim.read_body(0),
-                 sim.read_bodies, sim.snapshot, sim.restore, sim.save_checkpoint,
-                 lambda: sim.load_checkpoint("x.h5"), lambda: sim.update_runtime_params(omega=1.)):
-        with pytest.raises(RuntimeError, match="Simulation failed"):
-            call()
-    assert sim.field.curved.writes == [(0, 2e-3)]
-    sim.close()  # cleanup still works
-    assert sim._closed and sim.ctx.is_closed
-
-
-def test_simulation_stream_creation_failure_fails_closed(monkeypatch):
-    sim, jet = simulation(monkeypatch)
-    created = []
-    def stream():
-        created.append(1)
-        raise RuntimeError("stream creation failed")
-    monkeypatch.setattr(module.cuda, "Stream", stream, raising=False)
-    sim._stream = None
-    with pytest.raises(RuntimeError, match="stream creation failed"):
-        sim.set_jet_amplitude(0, 2e-3)
-    assert sim.bodies.jets[0] is jet and sim._failed is not None
-    assert sim.field.curved.writes == [] and created == [1]
-    for call in (lambda: sim.stream, lambda: sim.set_jet_amplitude(0, 2e-3)):
-        with pytest.raises(RuntimeError, match="Simulation failed"):
-            call()
-    assert created == [1]  # the public stream property does not retry creation
-    sim.ctx.detach_failure = True
-    with pytest.raises(RuntimeError, match="detach failed"):
-        sim.close()
-    assert not sim._closed
-    sim.close()  # close stays retryable after the failure
-    assert sim._closed and sim.ctx.is_closed
-
-
-def test_simulation_before_initialize_commits_host_only(monkeypatch):
-    sim, _ = simulation(monkeypatch)
-    sim._initialized = False
-    sim.set_jet_amplitude(0, -2e-3)
-    assert sim.field.curved.writes == [] and sim.bodies.jets[0].amplitude == -2e-3
-    sim.close()
-
-
-def stepper_state(run):
-    boundary = run._boundaries[2]
-    return boundary.tables["surface_velocity"].copy(), boundary.jets, run.jets[2]
-
-
-def test_stepper_invalid_input_writes_nothing_and_stays_ready():
-    run, module, _, _, _ = ready()
-    try:
-        velocity, jets, level_jets = stepper_state(run)
-        module.cuda.memcpy_htod.reset_mock()
-        for args, kw, error in [((0, a), {"level": 2}, ValueError) for a in BAD] + [
-                ((1, .01), {"level": 2}, IndexError), ((0, .01), {"level": 3}, ValueError)]:
-            with pytest.raises(error):
-                run.set_jet_amplitude(*args, **kw)
-        module.cuda.memcpy_htod.assert_not_called()
-        np.testing.assert_array_equal(run._boundaries[2].tables["surface_velocity"], velocity)
-        assert (run._boundaries[2].jets, run.jets[2]) == (jets, level_jets)
-        assert run._status == "ready"
-        run.set_jet_amplitude(0, .017, level=2)
-        assert run.jets[2][0].amplitude == .017
-    finally:
-        run.close()
-
-
-@pytest.mark.parametrize("where", ["upload", "synchronize"])
-def test_stepper_device_failure_keeps_host_and_blocks_reuse(where):
-    run, module, _, _, _ = ready()
-    try:
-        velocity, jets, level_jets = stepper_state(run)
-        if where == "upload":
-            module.cuda.memcpy_htod.side_effect = RuntimeError("upload failed")
-        else:
-            run._stream.synchronize.side_effect = RuntimeError("upload failed")
-        with pytest.raises(RuntimeError, match="upload failed"):
-            run.set_jet_amplitude(0, .017, level=2)
-        np.testing.assert_array_equal(run._boundaries[2].tables["surface_velocity"], velocity)
-        assert (run._boundaries[2].jets, run.jets[2]) == (jets, level_jets)
-        assert run._status == "failed"
-        module.cuda.memcpy_htod.side_effect = None
-        run._stream.synchronize.side_effect = None
-        for call in (lambda: run.set_jet_amplitude(0, .017, level=2), run.step, run.download):
-            with pytest.raises(RuntimeError, match="failed"):
-                call()
-    finally:
-        run.close()
-    assert run._status == "closed"
@@ -188,57 +188,6 @@ def jet_case(device, jets):
    return field, bodies


-def test_public_surface_exchange_for_jet_preserves_aperture_at_zero_and_reverse(device):
-    from CelerisLab.simulation import Simulation
-    jet = Jet(Sector(CENTER, 0., .6, 3.), Radial(CENTER, inward=False), "quartic", 2e-3)
-    field, bodies = jet_case(device, [jet])
-    sim = SimpleNamespace(bodies=bodies, field=field, _initialized=True,
-                          stream=SimpleNamespace(synchronize=device.synchronize))
-    sim._require_usable = Simulation._require_usable.__get__(sim)
-    cl = field.curved
-    assert bodies.get(0).surface_actuation is None
-    aperture, velocity = cl.aperture, cl.surface_velocity.copy()
-    assert aperture.any() and (~aperture).any()
-    # Synthetic per-link exchanges test readback/splitting, not kernel physics.
-    values = np.arange(cl.count * 3, dtype=np.float32).reshape(-1, 3)
-    device.htod(cl.link_exchange_gpu, values)
-    for amplitude in (2e-3, 0., -1e-3):
-        Simulation.set_jet_amplitude(sim, 0, amplitude)
-        result = Simulation.read_surface_exchange(sim, 0)
-        assert cl.aperture is aperture
-        np.testing.assert_array_equal(aperture, cl.jet_id >= 0)
-        np.testing.assert_allclose(cl.surface_velocity, velocity * (amplitude / 2e-3))
-        for name, mask in (("wall", ~aperture), ("aperture", aperture)):
-            np.testing.assert_array_equal(result[name], values[mask].sum(axis=0, dtype=np.float64))
-
-
-def test_public_surface_exchange_keeps_legacy_and_passive_guards(device):
-    from CelerisLab.simulation import Simulation
-    field = make_field(device)
-    bodies = manager(field, [circle(SurfaceActuation(0., .6, .002), radius=2.)])
-    bodies.sync_to_gpu(field)
-    sim = SimpleNamespace(bodies=bodies, field=field,
-                          stream=SimpleNamespace(synchronize=device.synchronize))
-    sim._require_usable = Simulation._require_usable.__get__(sim)
-    for value in Simulation.read_surface_exchange(sim, 0).values():
-        np.testing.assert_array_equal(value, 0.)
-    field.curved.free_gpu_columns()
-    with pytest.raises(RuntimeError, match="diagnostic is allocated"):
-        Simulation.read_surface_exchange(sim, 0)
-
-    # An exchange buffer elsewhere in the scene must not admit a passive body.
-    for jets in ([], [Jet(Sector(CENTER, 0., .6, 3.), Radial(CENTER))]):
-        field, bodies = jet_case(device, jets)
-        passive = bodies.add(circle(center=(2., 3.), radius=.6))
-        bodies.sync_to_gpu(field)
-        sim.bodies, sim.field = bodies, field
-        with pytest.raises(ValueError, match="Body has no surface actuation"):
-            Simulation.read_surface_exchange(sim, passive)
-        if not jets:
-            with pytest.raises(ValueError, match="Body has no surface actuation"):
-                Simulation.read_surface_exchange(sim, 0)
-
-
 def test_manager_passes_true_hits_and_reuploads_only_velocity(device):
    # CPU memory double only: checks host/device bookkeeping, not GPU numerics.
    jet = Jet(Sector(CENTER, 0., .6, 3.), Radial(CENTER, inward=False), "quartic", 2e-3)
@@ -1,183 +0,0 @@
-"""Research interface contracts; no CUDA context or physical validation."""
-import importlib.util
-from pathlib import Path
-from types import SimpleNamespace
-from unittest.mock import patch
-
-import numpy as np
-import pytest
-
-ROOT = Path(__file__).resolve().parents[2]
-spec = importlib.util.spec_from_file_location('karman_viv_research_driver', ROOT/'research/karman_viv/run.py')
-m = importlib.util.module_from_spec(spec)
-spec.loader.exec_module(m)
-
-
-def test_observation_unit_mapping_and_order():
-    norm = dict(force_norm_fact=2.,sens_deviation=np.arange(6)/10.,sens_norm_fact=np.ones(6)*3)
-    s=np.arange(6)*.001; f=np.arange(6)*.01
-    raw,obs,nclip=m.observation(s,f,2,norm)
-    np.testing.assert_array_equal(raw,np.asarray([*(s*156),*(f*2)],np.float32))
-    expected=np.hstack((raw[6:]/2,(raw[:6]-np.asarray(norm['sens_deviation'],np.float32))/3))
-    np.testing.assert_array_equal(obs,expected.astype(np.float32))
-    assert nclip==0
-
-
-def test_same_physical_signal_d20_d40():
-    norm=dict(force_norm_fact=1.,sens_deviation=np.zeros(6),sens_norm_fact=np.ones(6))
-    a=m.observation(np.ones(6)*.001,np.arange(6)*.01,1,norm)
-    b=m.observation(np.ones(6)*.0005,np.arange(6)*.005,2,norm)
-    np.testing.assert_array_equal(a[0],b[0]); np.testing.assert_array_equal(a[1],b[1])
-
-
-def test_zero_action_and_ccw_scale():
-    np.testing.assert_array_equal(m.wall_target(-m.BIAS/8,2),np.zeros(3))
-    np.testing.assert_allclose(m.wall_target(np.ones(3),2),[.04,.02,.06])
-    assert m.wall_target(np.ones(3),2)[0]/20 == .002
-
-
-def test_ema_equal_physical_time_and_interval_reset():
-    target=np.array([.01,-.02,.03]); coarse=np.zeros(3); fine=np.zeros(3)
-    for _ in range(13): coarse=m.ema(coarse,target,1)
-    for _ in range(52): fine=m.ema(fine,target,2)
-    np.testing.assert_allclose(fine,coarse,rtol=2e-15,atol=1e-17)
-    np.testing.assert_allclose(m.ema(np.zeros(3),target,2),(1-.9**.25)*target)
-
-
-def test_config_real_parser(tmp_path):
-    import json
-    from CelerisLab.config import load_lbm_config
-    path=tmp_path/'config.json';path.write_text(json.dumps(m.config(40)))
-    cfg=load_lbm_config(str(path));cfg.validate()
-    assert (cfg.nx,cfg.ny,cfg.velocity,cfg.viscosity)==(2559,1022,.005,.004)
-
-
-def test_structure_physical_scaling_and_no_damping():
-    coarse=m.Structure(2,1e-4,0,20);fine=m.Structure(2,2.5e-5,0,40)
-    assert fine.mass==4*coarse.mass
-    assert fine.stiffness==coarse.stiffness/4
-    assert fine.damping==0
-    assert fine.candidate(0)==(0.,0.)
-
-
-def test_observation_clipping_and_nonfinite():
-    norm=dict(force_norm_fact=1.,sens_deviation=np.zeros(6),sens_norm_fact=np.ones(6))
-    _,obs,n=m.observation(np.ones(6),np.ones(6),2,norm)
-    assert n==12 and np.array_equal(obs,np.ones(12,np.float32))
-    with pytest.raises(RuntimeError,match='nonfinite'):
-        m.observation(np.full(6,np.nan),np.zeros(6),2,norm)
-
-
-@pytest.mark.parametrize('mass_ratio', [2.,4.])
-def test_arm_step_order_and_native_rhs(tmp_path, mass_ratio):
-    import CelerisLab
-    from CelerisLab.body.motion import MovingTables
-    from contextlib import nullcontext
-    log=[];candidates=[];structure_args=[]
-    class Structure:
-        y=v=0.;mass=2.;stiffness=3.;frequency=.1
-        def __init__(self,*args): structure_args.append(args)
-        def candidate(self,f):
-            candidates.append(f)
-            return self.y+.001,self.v+.002
-    class Sim:
-        def __init__(self,*args): self.n=0
-        def __enter__(self): return self
-        def __exit__(self,*args): pass
-        def initialize(self): pass
-        def set_body(self,p,**kw): log.append(('set',p,kw))
-        def run(self,n,**kw): self.n+=1;log.append(('run',n,kw))
-        def moving_diagnostics(self):
-            a=np.zeros((3,len(MovingTables.DIAG)),np.float32)
-            a[:,MovingTables.DIAG.index('cme_y')]=self.n
-            a[:,MovingTables.DIAG.index('wen_y')]=10*self.n
-            a[:,MovingTables.DIAG.index('cover_jy')]=1000
-            return a
-        def read_force(self,p): return [0.,float(self.n),0.]
-        def read_sensor(self,p): return [.001,0.,0.]
-    seen=[]
-    model=SimpleNamespace(predict=lambda obs,**kw:(seen.append(obs.copy()) or np.ones(3)*.1,None))
-    norm=dict(force_norm_fact=1.,sens_deviation=np.zeros(6),sens_norm_fact=np.ones(6))
-    with patch.object(CelerisLab,'Simulation',Sim),patch.object(m,'Structure',Structure), \
-         patch.object(m,'add_scene',return_value=([1,2,3],[4,5,6])),patch.object(m,'install_seed',return_value={}), \
-         patch.object(m,'check_time'):
-        m.run_arm('controlled','cfg',2,2,2,None,7.,model,norm,tmp_path,0,1,mass_ratio=mass_ratio)
-    assert structure_args == [(mass_ratio,2.5e-5,0.,40.)]
-    assert candidates==[7.,33.,66.,99.]  # previous native force, NOT SI mean or node impulse
-    assert not seen[0].any() and len(seen)==2
-    assert [e[0] for e in log]==['set','set','set','run']*4
-    for e in log:
-        if e[0]=='set': assert e[2]['vy']==pytest.approx(.001) and e[2]['omega']!=0
-        else: assert e[2]==dict(zero_obs=True,sync_obs=True)
-    rows=np.load(tmp_path/'controlled/steps.npy')
-    np.testing.assert_allclose(rows[:,1],[.001,.002,.003,.004])
-    assert rows.shape==(4,18)
-    np.testing.assert_array_equal(rows[0,15:],rows[2,15:])  # EMA resets at SI boundary
-    signals=np.load(tmp_path/'controlled/signals.npz')
-    np.testing.assert_array_equal(signals['forces'][:,1],[3.,7.])  # interval CME *2, not CME+Wen
-
-
-def test_mass4_changes_inertia_and_stiffness_not_frequency_or_damping():
-    a=m.Structure(2,2.5e-5,0,40);b=m.Structure(4,2.5e-5,0,40)
-    assert b.mass==2*a.mass and b.stiffness==2*a.stiffness
-    assert b.frequency==a.frequency and b.damping==a.damping==0
-    np.testing.assert_allclose(b.candidate(.001),np.asarray(a.candidate(.001))/2,rtol=0,atol=0)
-
-
-def make_release(path):
-    import json
-    (path/'zero').mkdir()
-    case=dict(source=m.RELEASE_SOURCE,model_sha256=m.MODEL_SHA,norm_sha256=m.NORM_SHA,
-              smoke=False,D=40,U=.005,nu=.004,warmup_each=2048000,target_intervals=150,SI=3200)
-    (path/'case.json').write_text(json.dumps(case))
-    (path/'config.json').write_text(json.dumps(m.config(40)))
-    seed=(np.arange(18,dtype=np.float32),np.arange(18,dtype=np.float32)+1,np.zeros(2,np.int32))
-    np.savez(path/'release.npz',current=seed[0],spare=seed[1],flags=seed[2],clock=4576000,force=.003)
-    np.save(path/'target.npy',np.zeros((150,6),np.float32))
-    transfer=dict(zip(('current','spare','flags'),map(m.array_sha,seed)),clock=4576000)
-    (path/'zero/report.json').write_text(json.dumps(dict(release_transfer=transfer)))
-    return seed
-
-
-@pytest.mark.parametrize('damage', [None,'source','config','buffer','target','clock'])
-def test_saved_release_checks_provenance_and_exact_inputs(tmp_path, damage):
-    import json
-    seed=make_release(tmp_path)
-    if damage in ('source','config'):
-        file=tmp_path/('case.json' if damage=='source' else 'config.json')
-        data=json.loads(file.read_text());data['source' if damage=='source' else 'extra']='changed'
-        file.write_text(json.dumps(data))
-    elif damage in ('buffer','clock'):
-        with np.load(tmp_path/'release.npz') as z: data={k:z[k] for k in z.files}
-        if damage=='buffer': data['current'][0]+=1
-        else: data['clock']=4576001
-        np.savez(tmp_path/'release.npz',**data)
-    elif damage=='target': np.save(tmp_path/'target.npy',np.zeros((149,6),np.float32))
-    if damage:
-        with pytest.raises(ValueError): m.saved_release(tmp_path)
-    else:
-        loaded,force=m.saved_release(tmp_path)
-        assert loaded[3]==4576000 and force==.003
-        for actual,expected in zip(loaded[:3],seed): np.testing.assert_array_equal(actual,expected)
-
-
-def test_mass4_cli_uses_saved_release_without_warmup(tmp_path, monkeypatch):
-    import json
-    original=tmp_path/'original';original.mkdir();make_release(original)
-    norm=tmp_path/'norm.json';norm.write_text('{}');model=tmp_path/'model.zip'
-    out=tmp_path/'output';calls=[]
-    monkeypatch.setattr(m.sys,'argv',['run.py','--model',str(model),'--norm',str(norm),
-                                    '--out',str(out),'--mass-ratio','4','--release-dir',str(original)])
-    monkeypatch.setattr(m,'sha',lambda path:m.MODEL_SHA if path==model else m.NORM_SHA if path==norm else 'fixture-sha')
-    monkeypatch.setattr(m,'load_policy',lambda path:object())
-    monkeypatch.setattr(m.subprocess,'check_output',lambda *a,**k:'candidate\n')
-    monkeypatch.setattr(m,'precursor',lambda *a:pytest.fail('saved release must skip precursor'))
-    monkeypatch.setattr(m,'run_arm',lambda *a,**k:calls.append((a,k)))
-    m.main()
-    assert [a[0] for a,k in calls]==['zero','controlled']
-    assert all(a[2:5]==(2.,3200,400) and k=={'mass_ratio':4.} for a,k in calls)
-    receipt=json.loads((out/'case.json').read_text())
-    assert receipt['mass_ratio']==4 and receipt['structural_damping']==0 and receipt['warmup_executed']==0
-    assert receipt['exploratory'] and receipt['response_tU_D']==160
-    assert (out/'target.npy').read_bytes()==(original/'target.npy').read_bytes()
-    assert (out/'config.json').read_bytes()==(original/'config.json').read_bytes()
@@ -15,10 +15,6 @@ sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "validation"))
 from run_uniform_les_flow import source_guard, decode_macros, HERE, HEADER

 ROOT = HERE.parents[1]
-sys.path.insert(0, str(ROOT / "tests/unit"))
-from historical_tree import historical_tree, tracked
-
-A135 = "a135252ae78b47b57d7e77d19001700b3bedac8b"


 class GuardTests(unittest.TestCase):
@@ -46,23 +42,19 @@ class GuardTests(unittest.TestCase):
            decode_macros(invalid, w, cx, cy)

    def test_current_corrected_pins(self):
-        with TemporaryDirectory() as directory:
-            root = historical_tree(A135, directory)
-            with patch("run_uniform_les_flow.subprocess.check_output", return_value="historical-tree\n"):
-                identity = source_guard(root, "corrected", "a135252")
-            # base_commit comes from the pins file; the mock only feeds checkout_commit.
-            self.assertEqual(identity["base_commit"], A135)
-            self.assertEqual(identity["checkout_commit"], "historical-tree")
+        self.assertEqual(
+            source_guard(ROOT, "corrected", "a135252")["base_commit"],
+            "a135252ae78b47b57d7e77d19001700b3bedac8b",
+        )

    def test_corrected_and_tamper_guard(self):
        pins = json.loads((HERE / "data/les_flow/source_pins_a135252.json").read_text())
        with TemporaryDirectory() as directory:
-            origin = historical_tree(A135, Path(directory) / "origin")
-            root = Path(directory) / "fixture"
+            root = Path(directory)
            for name in pins["sources"]:
                dest = root / name
                dest.parent.mkdir(parents=True, exist_ok=True)
-                shutil.copyfile(origin / name, dest)
+                shutil.copyfile(ROOT / name, dest)
            with patch(
                "run_uniform_les_flow.subprocess.check_output",
                return_value="isolated-fixture\n",
@@ -95,26 +87,23 @@ class GuardTests(unittest.TestCase):

    def test_current_manifest_pins_actual_corrected_tree(self):
        pins = json.loads((HERE / "data/les_flow/source_pins_a135252.json").read_text())
-        self.assertEqual(pins["base_commit"], A135)
-        self.assertEqual(set(pins["sources"]), tracked(A135))
-        with TemporaryDirectory() as directory:
-            root = historical_tree(A135, directory)
-            for name, expected in pins["sources"].items():
-                self.assertEqual(hashlib.sha256((root / name).read_bytes()).hexdigest(), expected)
-            self.assertEqual(pins["sources"][HEADER], pins["candidate_header_sha256"])
-            self.assertNotEqual(pins["sources"][HEADER], pins["baseline_header_sha256"])
-            with self.assertRaisesRegex(RuntimeError, "Source pin mismatch"):
-                source_guard(root, "baseline", "a135252")
+        tracked = subprocess.check_output(["git", "-C", str(ROOT), "ls-files", "src"], text=True)
+        self.assertEqual(set(pins["sources"]), set(tracked.splitlines()))
+        for name, expected in pins["sources"].items():
+            self.assertEqual(hashlib.sha256((ROOT / name).read_bytes()).hexdigest(), expected)
+        self.assertEqual(pins["sources"][HEADER], pins["candidate_header_sha256"])
+        self.assertNotEqual(pins["sources"][HEADER], pins["baseline_header_sha256"])
+        with self.assertRaisesRegex(RuntimeError, "Source pin mismatch"):
+            source_guard(ROOT, "baseline", "a135252")

    def test_named_baseline_accepts_only_reversed_header(self):
        pins = json.loads((HERE / "data/les_flow/source_pins_a135252.json").read_text())
        with TemporaryDirectory() as directory:
-            origin = historical_tree(A135, Path(directory) / "origin")
-            root = Path(directory) / "fixture"
+            root = Path(directory)
            for name in pins["sources"]:
                dest = root / name
                dest.parent.mkdir(parents=True, exist_ok=True)
-                shutil.copyfile(origin / name, dest)
+                shutil.copyfile(ROOT / name, dest)
            subprocess.run(["git", "apply", "--reverse", str(HERE / "les/data/smagorinsky_normalization.patch")], cwd=root, check=True)
            with patch("run_uniform_les_flow.subprocess.check_output", return_value="baseline-fixture\n"):
                source_guard(root, "baseline", "a135252")
@@ -1,641 +0,0 @@
-"""Translating-circle host contract (docs/moving_bodies.md 4a, 5, 7).
-
-Real Simulation entrypoints with device doubles; no CUDA context or GPU work.
-"""
-import math
-from types import SimpleNamespace
-
-import pytest
-
-from CelerisLab.body.motion import MAX_STEP, R_MIN, MovingCircle, Translation
-
-BAD = (float("nan"), float("inf"))
-
-
-def circle(box=(-2., 2., -3., 3.), speed=.1):
-    return MovingCircle((50., 40.), 10., Translation(box, speed))
-
-
-def test_translation_and_radius_validation():
-    for box in ((0., 1., -1., 1.)[:3], (.5, 1., -1., 1.), (-1., 1., BAD[0], 1.)):
-        with pytest.raises(ValueError):
-            Translation(box, .1)
-    for speed in (0., MAX_STEP + 1e-9) + BAD:
-        with pytest.raises(ValueError):
-            Translation((0., 0., -1., 1.), speed)
-    with pytest.raises(ValueError):
-        MovingCircle((0., 0.), R_MIN - .1, Translation((0., 0., -1., 1.), .1))
-
-
-def test_targets_validate_against_applied_and_last_wins():
-    c = circle()
-    c.set_target((0., .3), (0., .05))
-    c.set_target((0., .5), (0., .05))  # second setter replaces, checked vs applied (0, 0)
-    assert c.pending == ((0., .5), (0., .05))
-    for offset, velocity in (((0., .51), (0., 0.)),           # Euclidean bound
-                             ((.36, .36), (0., 0.)),          # |dc|_2 = .509
-                             ((0., 3.1), (0., 0.)),           # outside box
-                             ((0., .1), (0., .11)),           # speed bound
-                             ((0., 0.), (0., .01)),           # hold with sliding velocity
-                             ((BAD[0], 0.), (0., 0.)), ((0., 0.), (0., BAD[1]))):
-        with pytest.raises(ValueError):
-            c.set_target(offset, velocity)
-        assert c.pending == ((0., .5), (0., .05))  # invalid replacement keeps the old target
-    c.set_target((.35, .35), (0., 0.))  # |dc|_2 = .495 inside the bound
-    assert c.applied == (0., 0.)
-
-
-def test_record_commit_and_hold(monkeypatch):
-    sim, writes, c = routed_advancing_simulation(monkeypatch)
-    assert c.record() == ((50., 40.), (50., 40.), (0., 0.))
-    sim.set_body(0, offset=(0., .25), vy=.05)
-    assert c.record() == ((50., 40.), (50., 40.25), (0., .05))
-    seen_at_sync = []
-    sim.run(1, stream=SimpleNamespace(synchronize=lambda: seen_at_sync.append(c.applied)))
-    assert seen_at_sync == [(0., 0.), (0., .25)]  # commit between step sync and hold sync
-    uploads = [w[1][0] for w in writes if isinstance(w, tuple) and w[0] == "upload"]
-    assert uploads == [((50., 40.), (50., 40.25), (0., .05)),
-                       ((50., 40.25), (50., 40.25), (0., 0.))]
-    assert c.applied == (0., .25) and c.pending is None  # offset-only commit
-    sim.run(1, stream=STREAM)  # no new target: hold step
-    uploads = [w[1][0] for w in writes if isinstance(w, tuple) and w[0] == "upload"]
-    assert uploads[-1] == ((50., 40.25), (50., 40.25), (0., 0.)) and c.applied == (0., .25)
-    sim.set_body(0, offset=(0., 0.), vy=-.05)  # zero offset is a real target
-    assert c.pending == ((0., 0.), (0., -.05))
-    sim.run(1, stream=STREAM)
-    assert c.applied == (0., 0.) and c.pending is None
-
-
-@pytest.mark.parametrize("stage", ("upload", "step", "synchronize"))
-def test_failure_after_upload_attempt_is_fail_closed(monkeypatch, stage):
-    sim, writes, c = routed_advancing_simulation(monkeypatch, fail="upload" if stage == "upload" else None)
-    sim.set_body(0, offset=(0., .25), vy=.05)
-
-    def fail(*a, **k):
-        raise RuntimeError(f"{stage} failed")
-    if stage == "step":
-        sim.stepper._step = fail
-    stream = SimpleNamespace(synchronize=fail) if stage == "synchronize" else STREAM
-    with pytest.raises(RuntimeError, match=f"{stage} failed"):
-        sim.run(1, stream=stream)
-    assert c.failed and c.applied == (0., 0.) and c.pending == ((0., .25), (0., .05))
-    assert sim._failed is not None and sim.stepper.blocked == sim._failed
-    for later in (c.record, lambda: sim.set_body(0, offset=(0., .1), vy=0.)):
-        with pytest.raises(RuntimeError, match="unknown"):
-            later()
-    with pytest.raises(RuntimeError, match="Simulation failed"):
-        sim.run(1, stream=STREAM)
-    with pytest.raises(RuntimeError, match="moving circle step failed"):
-        sim.stepper.step(1, action_gpu=None, obs_gpu=None)
-
-
-def test_band_covers_offset_box_with_margin():
-    assert circle().band() == (50 - 2 - 10 - 2, 50 + 2 + 10 + 2, 40 - 3 - 10 - 2, 40 + 3 + 10 + 2)
-
-
-# D2Q9 non-rest directions, paired order of lbm/descriptors.
-_CX = (1, -1, 0, 0, 1, -1, 1, -1)
-_CY = (0, 0, 1, -1, 1, -1, -1, 1)
-
-
-def _inside(x: int, y: int, c, r: float) -> bool:
-    return (x - c[0]) ** 2 + (y - c[1]) ** 2 < r * r
-
-
-def empty_donor_cells(c_old, c_new, radius: float):
-    """Fresh cells (inside c_old, outside c_new) whose donor set V(x) is empty."""
-    r = radius
-    xs = range(math.floor(min(c_old[0], c_new[0]) - r) - 1, math.ceil(max(c_old[0], c_new[0]) + r) + 2)
-    ys = range(math.floor(min(c_old[1], c_new[1]) - r) - 1, math.ceil(max(c_old[1], c_new[1]) + r) + 2)
-    empty = []
-    for x in xs:
-        for y in ys:
-            if not _inside(x, y, c_old, r) or _inside(x, y, c_new, r):
-                continue
-            if not any(not _inside(x + cx, y + cy, c_old, r) and not _inside(x + cx, y + cy, c_new, r)
-                       for cx, cy in zip(_CX, _CY)):
-                empty.append((x, y))
-    return empty
-
-
-def enumerate_donor_coverage(radius: float, positions: int = 8, directions: int = 16) -> int:
-    """Count empty-donor fresh cells over sub-cell centres and moves of MAX_STEP.
-
-    Evidence for the declared bounds (radius >= R_MIN, |dc|_2 <= MAX_STEP),
-    not a proof; the device keeps the ``no_donor`` counter.
-    """
-    count = 0
-    for i in range(positions):
-        for j in range(positions):
-            c_old = (i / positions, j / positions)
-            for k in range(directions):
-                a = 2.0 * math.pi * k / directions
-                c_new = (c_old[0] + MAX_STEP * math.cos(a), c_old[1] + MAX_STEP * math.sin(a))
-                count += len(empty_donor_cells(c_old, c_new, radius))
-    return count
-
-
-@pytest.mark.parametrize("radius", (R_MIN, 4.3, 7.5, 12.0))
-def test_refill_donor_sets_nonempty_within_bounds(radius):
-    # Evidence for R >= R_MIN and |dc|_2 <= MAX_STEP on a fixed sample, not a proof.
-    assert enumerate_donor_coverage(radius) == 0
-
-
-pytest.importorskip("pycuda.driver")
-from CelerisLab import simulation as module  # noqa: E402
-from tests.unit.test_simulation_lifecycle import Owner, make_simulation  # noqa: E402
-
-
-class ClosableOwner(Owner):
-    """Owner double that refuses activation after close, like CudaContext.activate."""
-    def activate(self):
-        if self.is_closed:
-            raise RuntimeError("CUDA context is closed")
-        return super().activate()
-
-
-def moving_simulation(monkeypatch, *, moving=True):
-    sim = make_simulation(monkeypatch)
-    obj = SimpleNamespace(motion=circle() if moving else None, obj_id=0,
-                          center=(50., 40.), radius=10.)
-    writes = []
-    sim._failed, sim._initialized = None, True
-    sim.bodies = SimpleNamespace(objects=[obj], count=1, jets=[], action_gpu=None, obs_gpu=None,
-                                 has_pending_edit=lambda: False,
-                                 _upload_action_async=lambda s: writes.append("action"),
-                                 zero_obs_async=lambda s: writes.append("obs"),
-                                 increment_obs_steps=lambda n: writes.append("count"),
-                                 download_obs_full_async=lambda s: writes.append("download"))
-    sim.stepper = SimpleNamespace(step=lambda n, **k: writes.append(("step", n)), blocked=None,
-                                  moving=None)
-    sim._assert_runtime_contracts = lambda: None
-    return sim, writes
-
-
-STREAM = SimpleNamespace(synchronize=lambda: None)
-
-
-def test_positive_steps_rejected_before_device_writes(monkeypatch):
-    sim, writes = moving_simulation(monkeypatch)
-    sim.bodies.objects[0].motion.set_target((0., .1), (0., .01))
-    sim.bodies.objects[0].motion.applied = (0., 0.)
-    for call in (lambda: sim.run(1, stream=STREAM), lambda: sim.run(5, stream=STREAM),
-                 lambda: sim.step(), lambda: sim.run(3, stream=STREAM, checkpoint_interval=1)):
-        with pytest.raises(RuntimeError, match="moving kernels"):
-            call()
-    with pytest.raises(RuntimeError, match="moving kernels"):  # nominal at rest as well
-        sim.bodies.objects[0].motion.pending = None
-        sim.run(1)
-    sim.bodies.objects[0].state = SimpleNamespace(omega=.02)  # spin does not lift the guard
-    with pytest.raises(RuntimeError, match="moving kernels"):
-        sim.run(2, stream=STREAM)
-    assert writes == [] and sim.bodies.objects[0].motion.applied == (0., 0.)
-
-
-def test_run_zero_keeps_pending_and_static_runs_proceed(monkeypatch):
-    sim, writes = moving_simulation(monkeypatch)
-    motion = sim.bodies.objects[0].motion
-    motion.set_target((0., .1), (0., .01))
-    sim.run(0, stream=STREAM)  # existing action/obs work only; no motion upload or commit
-    assert motion.pending == ((0., .1), (0., .01)) and motion.applied == (0., 0.)
-    assert ("step", 0) in writes
-    static, writes = moving_simulation(monkeypatch, moving=False)
-    static.save_checkpoint = lambda *a: writes.append("checkpoint")
-    static.run(3, stream=STREAM)
-    static.run(4, stream=STREAM, checkpoint_interval=2)
-    assert writes.count(("step", 3)) == 1 and writes.count(("step", 2)) == 2
-
-
-def test_direct_stepper_entry_is_guarded():
-    from CelerisLab.lbm.stepper import LBMStepper
-    launches = []
-    module = SimpleNamespace(get_function=lambda name: lambda *a, **k: launches.append(name))
-    cfg = SimpleNamespace(streaming="double_buffer", threads_per_block=128, is_d2q9=True,
-                          nx=64, ny=32, nz=1)
-    field = SimpleNamespace(ddf_gpu="ddf", temp_gpu="temp", n_curved=0)
-    stepper = LBMStepper(field, module, cfg)
-    assert stepper.blocked is None
-    stepper.blocked = "translating circles need the moving kernels"
-    for n in (1, 3):
-        with pytest.raises(RuntimeError, match="moving kernels"):
-            stepper.step(n, action_gpu=None, obs_gpu=None)
-    assert launches == [] and (field.ddf_gpu, field.temp_gpu) == ("ddf", "temp")
-    assert stepper.step_count == 0
-    stepper.step(0, action_gpu=None, obs_gpu=None)  # zero steps stay a no-op
-    assert launches == [] and stepper.step_count == 0
-
-
-def test_moving_body_rejects_topology_and_checkpoint(monkeypatch):
-    sim, _ = moving_simulation(monkeypatch)
-    for call in (sim.sync_bodies, sim.save_checkpoint, lambda: sim.load_checkpoint("x.h5")):
-        with pytest.raises(ValueError, match="translating circles"):
-            call()
-
-
-# -- Real-object routing, initialize rejections, packing, lifecycle -------------
-import numpy as np  # noqa: E402
-
-from CelerisLab.body.geometry.circle import CircleGeometry  # noqa: E402
-from CelerisLab.body.manager import ObjectManager  # noqa: E402
-from CelerisLab.body.objects import SimObject  # noqa: E402
-from CelerisLab.lbm.descriptors import FLUID, SOLID  # noqa: E402
-
-
-class Cfg:
-    dim, is_d3q19, is_d2q9 = 2, False, True
-    streaming, ddf_shifting, store_precision, y_wall_bc = "double_buffer", False, "FP32", "bounce_back"
-
-
-def body(x, y, r, translation=None, **kw):
-    obj = SimObject(obj_id=-1, geometry=CircleGeometry(x, y, r), center=(x, y), radius=r, **kw)
-    if translation is not None:
-        obj.motion = MovingCircle((x, y), r, translation)
-    return obj
-
-
-def routed_simulation(monkeypatch):
-    sim = make_simulation(monkeypatch)
-    sim._failed, sim._initialized, sim.lbm_cfg = None, False, Cfg()
-    sim.stepper = SimpleNamespace(blocked=None)
-    sim.bodies = ObjectManager(nx=120, ny=80, nz=1, nq=9, cfg=Cfg())
-    return sim
-
-
-def test_add_body_and_set_body_route_targets(monkeypatch):
-    sim = routed_simulation(monkeypatch)
-    bid = sim.add_body("circle", (50., 40.), 10., translation=Translation((-2., 2., -3., 3.), .1))
-    still = sim.add_body("circle", (100., 40.), 5.)
-    motion = sim.bodies.get(bid).motion
-    sim._moving_tables = "tables"
-    sim._attach_moving()
-    assert sim.stepper.blocked is None
-    sim.set_body(bid, offset=(0., .3), vy=.05)
-    assert sim.stepper.blocked == module.PENDING_BLOCKED  # direct steps never consume a target
-    sim.set_body(bid, offset=(0., .4), vy=.05)  # last wins
-    for kwargs in (dict(offset=(0., .6)), dict(vy=.05), dict(vx=.05),
-                   dict(offset=(0., .1), vy=.2), dict(offset=(0., 0.), vy=.01)):
-        with pytest.raises(ValueError):
-            sim.set_body(bid, **kwargs)
-        assert motion.pending == ((0., .4), (0., .05))  # invalid input keeps the target
-    sim.set_body(bid, omega=.01)  # omega-only keeps the pending target
-    obj = sim.bodies.get(bid)
-    assert obj.state.omega == .01 and (obj.state.vx, obj.state.vy) == (0., 0.)
-    assert motion.pending == ((0., .4), (0., .05)) and motion.applied == (0., 0.)
-    with pytest.raises(ValueError, match="not declared"):
-        sim.set_body(still, offset=(0., .1))
-    sim.set_body(still, vx=.01)  # stationary API unchanged
-    assert sim.bodies.get(still).state.vx == .01 and sim.bodies.get(still).motion is None
-    for kwargs in (dict(type="sensor"), dict(surface_actuation=dict(angle=0., half_width=.2,
-                                                                    normal_velocity=.01))):
-        kind = kwargs.pop("type", "circle")
-        with pytest.raises(ValueError, match="translation"):
-            sim.add_body(kind, (20., 20.), 5., translation=Translation((0., 0., 0., 0.), .1),
-                         **kwargs)
-
-
-class Tables:
-    """MovingTables double: records uploads, steps and diagnostics reads."""
-    DIAG = ("no_donor",)
-
-    def __init__(self, log, no_donor=0., fail=None):
-        self.log, self.no_donor, self.fail = log, no_donor, fail
-
-    def upload_records(self, circles, stream):
-        records = [m.record() for m, _ in circles]
-        self.log.append(("upload", records))
-        uploads = sum(1 for w in self.log if isinstance(w, tuple) and w[0] == "upload")
-        if self.fail == "upload" or (self.fail == "hold_upload" and uploads == 2):
-            raise RuntimeError("upload failed")
-        return any(r[0] != r[1] for r in records)
-
-    def zero_diagnostics(self, stream):
-        self.log.append("zero_diag")
-
-    def download_diagnostics(self):
-        return np.array([[self.no_donor]], np.float32)
-
-
-def advancing_simulation(monkeypatch, **tables):
-    sim, writes = moving_simulation(monkeypatch)
-    sim.bodies.objects[0].motion = circle()
-    sim.stepper = SimpleNamespace(
-        moving=Tables(writes, **tables), blocked=None,
-        _step=lambda n, advance=False, **k: writes.append(("step", n, advance)))
-    from CelerisLab.lbm.stepper import LBMStepper
-    sim.stepper.step = LBMStepper.step.__get__(sim.stepper)  # real public entry
-    sim._moving_tables = sim.stepper.moving
-    return sim, writes, sim.bodies.objects[0].motion
-
-
-def routed_advancing_simulation(monkeypatch, **tables):
-    """Real body registration, target routing, run and owner hook; double device I/O."""
-    sim = routed_simulation(monkeypatch)
-    bid = sim.add_body("circle", (50., 40.), 10., translation=Translation((-2., 2., -3., 3.), .1))
-    sim._initialized = True
-    sim._assert_runtime_contracts = lambda: None
-    writes = []
-    monkeypatch.setattr(sim.bodies, "_upload_action_async", lambda s: writes.append("action"))
-    monkeypatch.setattr(sim.bodies, "zero_obs_async", lambda s: writes.append("obs"))
-    monkeypatch.setattr(sim.bodies, "download_obs_full_async", lambda s: writes.append("download"))
-    sim.stepper = SimpleNamespace(
-        moving=Tables(writes, **tables), blocked=None,
-        _step=lambda n, advance=False, **k: writes.append(("step", n, advance)))
-    from CelerisLab.lbm.stepper import LBMStepper
-    sim.stepper.step = LBMStepper.step.__get__(sim.stepper)
-    sim._moving_tables = sim.stepper.moving
-    sim._attach_moving()
-    return sim, writes, sim.bodies.get(bid).motion
-
-
-def test_run_one_advances_and_commits_after_sync(monkeypatch):
-    sim, writes, motion = advancing_simulation(monkeypatch)
-    motion.set_target((0., .25), (0., .05))
-    with pytest.raises(ValueError, match="run\\(1\\)"):  # multi-step with a target
-        sim.run(2, stream=STREAM)
-    assert writes == [] and motion.pending is not None
-    sim.run(0, stream=STREAM)  # zero steps never consume the target
-    assert motion.pending is not None
-    sim.run(1, stream=STREAM)
-    uploads = [w for w in writes if isinstance(w, tuple) and w[0] == "upload"]
-    assert uploads[0][1] == [((50., 40.), (50., 40.25), (0., .05))]
-    assert uploads[1][1] == [((50., 40.25), (50., 40.25), (0., 0.))]  # first hold after move
-    assert ("step", 1, True) in writes
-    assert motion.applied == (0., .25) and motion.pending is None
-    writes.clear()
-    sim.run(3, stream=STREAM)  # hold steps: no advance
-    assert ("step", 3, False) in writes and motion.applied == (0., .25)
-
-
-def test_zero_motion_target_is_consumed_by_run_one(monkeypatch):
-    sim, writes, motion = advancing_simulation(monkeypatch)
-    motion.set_target((0., 0.), (0., 0.))          # equal to applied: a hold target
-    sim._attach_moving()
-    assert sim.stepper.blocked == module.PENDING_BLOCKED
-    sim.run(1, stream=STREAM)
-    assert motion.pending is None and motion.applied == (0., 0.)
-    assert sim.stepper.blocked is None and ("step", 1, False) in writes
-    writes.clear()
-    sim.run(3, stream=STREAM)                      # no stale latch
-    assert ("step", 3, False) in writes
-
-
-@pytest.mark.parametrize("streaming,d2q9,bound", [("double_buffer", True, True),
-                                                  ("double_buffer", False, False),
-                                                  ("esopull", True, False)])
-def test_moving_kernels_bound_only_for_d2q9_double_buffer(monkeypatch, streaming, d2q9, bound):
-    from CelerisLab.lbm import stepper as stepper_module
-    monkeypatch.setattr(stepper_module.cuda, "mem_alloc", lambda n: object())
-    moving = {"MovingCircleLinks", "MovingCircleCells"}
-
-    def get_function(name):
-        if name in moving and not (d2q9 and streaming == "double_buffer"):
-            raise KeyError(name)                 # absent from D3Q19 / EsoPull modules
-        return lambda *a, **k: None
-    cfg = SimpleNamespace(streaming=streaming, threads_per_block=128, is_d2q9=d2q9,
-                          nx=16, ny=8, nz=4, nq=9 if d2q9 else 19)
-    stepper = stepper_module.LBMStepper(SimpleNamespace(), SimpleNamespace(get_function=get_function), cfg)
-    assert (stepper.moving_fn is not None) == bound and (stepper.moving_cells_fn is not None) == bound
-
-
-def test_moving_diagnostics_empty_shape_matches_layout(monkeypatch):
-    from CelerisLab.body.motion import MovingTables
-    sim = make_simulation(monkeypatch)
-    sim._failed, sim.stepper = None, SimpleNamespace(moving=None)
-    assert sim.moving_diagnostics().shape == (0, MovingTables.DIAG_FLOATS)
-
-
-@pytest.mark.parametrize("failure", ("upload", "first_sync", "no_donor", "hold_upload",
-                                     "hold_sync"))
-def test_failed_advance_fails_simulation(monkeypatch, failure):
-    kwargs = dict(no_donor=1.) if failure == "no_donor" else dict(fail=failure)
-    sim, writes, motion = advancing_simulation(monkeypatch, **kwargs)
-    motion._on_failure = sim._fail_moving
-    motion.set_target((0., .25), (0., .05))
-    syncs = []
-
-    def synchronize():  # stands in for an asynchronous failure surfacing at sync
-        syncs.append(1)
-        if (failure, len(syncs)) in (("first_sync", 1), ("hold_sync", 2)):
-            raise RuntimeError("sync failed")
-    with pytest.raises(RuntimeError):
-        sim.run(1, stream=SimpleNamespace(synchronize=synchronize))
-    # Before the step-group sync and no_donor check nothing is committed; the hold
-    # record is staged after the commit (applied already matches the moved device).
-    committed = failure in ("hold_upload", "hold_sync")
-    assert motion.applied == ((0., .25) if committed else (0., 0.))
-    assert (motion.pending is None) == committed
-    assert motion.failed and sim._failed is not None
-    assert sim.stepper.blocked == sim._failed  # direct stepper reuse refused too
-    with pytest.raises(RuntimeError, match="Simulation failed"):
-        sim.run(1, stream=STREAM)
-
-
-def test_failed_hold_step_blocks_the_direct_stepper(monkeypatch):
-    # No target is pending, so only the failure latch can refuse direct steps.
-    from CelerisLab.lbm.stepper import LBMStepper
-    sim, writes, motion = advancing_simulation(monkeypatch, fail="upload")
-    motion._on_failure = sim._fail_moving
-    launches = []
-    kernels = SimpleNamespace(get_function=lambda name: lambda *a, **k: launches.append(name))
-    cfg = SimpleNamespace(streaming="double_buffer", threads_per_block=128, is_d2q9=True,
-                          nx=64, ny=32, nz=1)
-    field = SimpleNamespace(ddf_gpu="ddf", temp_gpu="temp", flag_gpu="flag", n_curved=0)
-    stepper = LBMStepper(field, kernels, cfg)
-    stepper.moving = sim.stepper.moving
-    sim.stepper = stepper
-    assert motion.pending is None and stepper.blocked is None
-    with pytest.raises(RuntimeError, match="upload failed"):
-        sim.run(2, stream=STREAM)  # hold step
-    assert sim._failed is not None and stepper.blocked == sim._failed
-    with pytest.raises(RuntimeError, match="moving circle step failed"):
-        stepper.step(1, action_gpu=None, obs_gpu=None)
-    assert launches == [] and stepper.step_count == 0
-    assert (field.ddf_gpu, field.temp_gpu) == ("ddf", "temp")
-
-
-def test_moving_tables_layout_and_attachment(monkeypatch):
-    from CelerisLab.body.motion import MovingTables
-    a = MovingCircle((50., 40.), 10., Translation((-1., 1., -3., 3.), .1))
-    b = MovingCircle((90.25, 30.5), 5., Translation((0., 0., 0., 0.), .1))
-    band, geom = MovingTables.layout([(a, 2), (b, 5)])
-    wa, ha = 63 - 37 + 1, 55 - 25 + 1
-    assert band == [37, 25, wa, ha, 0, 2, 83, 23, 16, 16, wa * ha * 8, 5]
-    assert geom == [50., 40., 50., 40., 10., 0., 0., 90.25, 30.5, 90.25, 30.5, 5., 0., 0.]  # hold
-    sim = routed_simulation(monkeypatch)
-    sim.add_body("circle", (50., 40.), 10., translation=Translation((0., 0., 0., 0.), .1))
-    sim._moving_tables = "tables"
-    sim._attach_moving()
-    assert sim.stepper.moving == "tables" and sim.stepper.blocked is None
-    sim._moving_tables = None
-    sim._attach_moving()
-    assert sim.stepper.moving is None and sim.stepper.blocked is not None
-
-
-class CountingOwner(Owner):
-    """Owner double that counts nested activations like CudaContext."""
-    def __init__(self):
-        super().__init__()
-        self.active = 0
-
-    def activate(self):
-        from contextlib import contextmanager
-
-        @contextmanager
-        def scope():
-            self.active += 1
-            try:
-                yield self
-            finally:
-                self.active -= 1
-        return scope()
-
-
-def test_public_diagnostics_keep_owner_active_through_sync_and_download(monkeypatch):
-    sim = make_simulation(monkeypatch)
-    sim.ctx, sim._failed = CountingOwner(), None
-    seen = []
-    sim._stream = SimpleNamespace(synchronize=lambda: seen.append(("sync", sim.ctx.active)))
-    expected = np.arange(6, dtype=np.float32).reshape(1, 6)
-
-    def download():
-        seen.append(("download", sim.ctx.active))
-        return expected
-    sim.stepper = SimpleNamespace(moving=SimpleNamespace(download_diagnostics=download))
-    assert sim.moving_diagnostics() is expected
-    assert [name for name, _ in seen] == ["sync", "download"]
-    assert all(active > 0 for _, active in seen) and sim.ctx.active == 0
-
-
-def test_stepper_launches_moving_links_before_static_curved():
-    from CelerisLab.lbm.stepper import LBMStepper
-    launches = []
-    module = SimpleNamespace(get_function=lambda name: lambda *a, **k: launches.append((name, a, k)))
-    cfg = SimpleNamespace(streaming="double_buffer", threads_per_block=128, is_d2q9=True,
-                          nx=64, ny=32, nz=1)
-    curved = SimpleNamespace(**{f"{name}_gpu": name for name in (
-        "fluid_idx", "dir", "q", "rx", "ry", "rz", "fallback_class", "body_id")},
-        surface_velocity=None, surface_velocity_gpu=None, link_exchange_gpu=None)
-    field = SimpleNamespace(ddf_gpu="ddf", temp_gpu="temp", flag_gpu="flag", n_curved=5,
-                            curved=curved, invalidate_host_ddf_cache=lambda: None)
-    stepper = LBMStepper(field, module, cfg)
-    stepper._launch_force_region = stepper._launch_sensor = lambda *a, **k: None
-    stepper.moving = SimpleNamespace(band_gpu="band", geom_gpu="geom", diag_gpu="diag",
-                                     slot_debug_gpu=None, n_bodies=1, n_slots=300)
-    stepper.step(2, action_gpu="act", obs_gpu="obs")
-    names = [name for name, _, _ in launches]
-    assert names == ["MovingCircleLinks", "CurvedBoundaryKernel", "OneStep"] * 2
-    assert stepper.step_count == 2
-    assert launches[1][1][0] == "ddf" and launches[3][1][0] == "temp"  # swap between steps
-    args, kw = launches[0][1], launches[0][2]
-    assert args[:4] == ("ddf", "flag", "band", "geom") and int(args[5]) == 300
-    assert kw["grid"] == (3, 1, 1) and kw["block"] == (128, 1, 1)
-
-
-def test_recompile_installs_a_guarded_stepper(monkeypatch):
-    from CelerisLab.lbm.stepper import LBMStepper
-    sim = routed_simulation(monkeypatch)
-    sim.add_body("circle", (50., 40.), 10., translation=Translation((0., 0., -1., 1.), .1))
-    launches = []
-    kernel_module = SimpleNamespace(get_function=lambda name: lambda *a, **k: launches.append(name))
-    monkeypatch.setattr(module.compiler, "build_module", lambda *a, **k: kernel_module)
-    sim.lbm_cfg = SimpleNamespace(validate_runtime=lambda: None, viscosity=.01, omega=1.,
-                                  streaming="double_buffer", threads_per_block=128,
-                                  is_d2q9=True, nx=120, ny=80, nz=1)
-    sim._compiled_viscosity = .01
-    sim._assert_allocation_contract = lambda: None
-    sim._resolve_compile_arch = lambda: "sm_70"
-    sim._assert_object_count_contract = lambda **k: None
-    sim.field = SimpleNamespace(module=None, invalidate_module_constant_cache=lambda: None,
-                                _upload_params=lambda: None, _runtime_params={},
-                                ddf_gpu="ddf", temp_gpu="temp", n_curved=0)
-    sim.stepper = SimpleNamespace(_step_count=7, blocked=None)
-    sim._recompile()
-    assert isinstance(sim.stepper, LBMStepper) and sim.stepper.step_count == 7
-    with pytest.raises(RuntimeError, match="moving kernels"):
-        sim.stepper.step(1, action_gpu=None, obs_gpu=None)
-    assert launches == [] and (sim.field.ddf_gpu, sim.field.temp_gpu) == ("ddf", "temp")
-    assert sim.stepper.step_count == 7
-
-
-def validate(monkeypatch, objects, flags=None, **cfg):
-    sim = routed_simulation(monkeypatch)
-    for obj in objects:
-        sim.bodies.add(obj)
-    for name, value in cfg.items():
-        setattr(sim.lbm_cfg, name, value)
-    base = np.full(120 * 80, FLUID, np.uint16) if flags is None else flags
-    sim.field = SimpleNamespace(nx=120, ny=80, build_channel_flags=lambda: base.copy())
-    sim._validate_moving_bodies()
-
-
-def test_initialize_rejects_band_and_modes(monkeypatch):
-    t = Translation((-1., 1., -3., 3.), .1)
-    validate(monkeypatch, [body(50., 40., 10., t), body(100., 40., 5.)])  # accepted
-    walls = np.full(120 * 80, FLUID, np.uint16)
-    walls[60 + 30 * 120] = SOLID
-    cases = [([body(10., 40., 10., t)], None, {}, "domain edge"),
-             ([body(50., 40., 10., t)], walls, {}, "non-fluid"),
-             ([body(50., 40., 10., t), body(68., 40., 4.)], None, {}, "overlaps"),
-             ([body(50., 40., 10., t), body(50., 60., 3., is_sensor=True)], None, {}, "overlaps"),
-             ([body(50., 40., 10., t), body(64., 40., 3., is_force_region=True)], None, {}, "overlaps"),
-             ([body(50., 40., 10., t)], None, {"streaming": "esopull"}, "double_buffer"),
-             ([body(50., 40., 10., t)], None, {"ddf_shifting": True}, "unshifted"),
-             ([body(50., 40., 10., t)], None, {"is_d2q9": False}, "D2Q9")]
-    for objects, flags, cfg, match in cases:
-        with pytest.raises(ValueError, match=match):
-            validate(monkeypatch, objects, flags, **cfg)
-
-
-def test_initialize_validates_before_mutation(monkeypatch):
-    sim = routed_simulation(monkeypatch)
-    sim.bodies.add(body(10., 40., 10., Translation((0., 0., 0., 0.), .1)))
-    uploads = []
-    sim.field = SimpleNamespace(nx=120, ny=80, build_channel_flags=lambda: np.full(9600, FLUID, np.uint16),
-                                upload_flags=lambda: uploads.append("flags"))
-    sim._assert_allocation_contract = lambda: None
-    with pytest.raises(ValueError, match="domain edge"):
-        sim.initialize()
-    assert uploads == [] and not sim._initialized
-
-
-def test_moving_circle_excluded_from_static_links():
-    def manager(*objects):
-        mgr = ObjectManager(nx=120, ny=80, nz=1, nq=9, cfg=Cfg())
-        ids = [mgr.add(obj) for obj in objects]
-        return mgr, ids
-    reference_mgr, _ = manager(body(100., 40., 5.), body(20., 40., 6.))
-    mixed_mgr, ids = manager(body(100., 40., 5.), body(20., 40., 6.),
-                             body(55., 40., 10., Translation((0., 0., -1., 1.), .1)))
-    reference = reference_mgr.build_compact_lists_for(reference_mgr.objects)
-    mixed = mixed_mgr.build_compact_lists_for(mixed_mgr.objects)
-    for a, b in zip(reference[:8], mixed[:8]):  # static link columns byte-identical
-        assert np.asarray(a).tobytes() == np.asarray(b).tobytes()
-    assert len(reference[0]) > 0 and ids[2] not in set(np.asarray(mixed[3]).tolist())
-
-
-def test_failed_moving_step_marks_simulation_failed(monkeypatch):
-    sim, writes, motion = routed_advancing_simulation(monkeypatch)
-    sim.ctx = ClosableOwner()
-    sim.set_body(0, offset=(0., .2), vy=.05)
-
-    def fail(*_):
-        raise RuntimeError("sync failed")
-    with pytest.raises(RuntimeError, match="sync failed"):
-        sim.run(1, stream=SimpleNamespace(synchronize=fail))
-    assert sim._failed is not None and motion.applied == (0., 0.)
-    for call in (lambda: sim.run(0), lambda: sim.run(1), sim.step, sim.sync_bodies,
-                 sim.save_checkpoint, lambda: sim.load_checkpoint("x.h5")):
-        with pytest.raises(RuntimeError, match="Simulation failed"):
-            call()
-    with pytest.raises(RuntimeError, match="unknown"):  # no retry on the failed circle
-        sim.set_body(0, offset=(0., .1), vy=.05)
-    with sim.ctx.activate():  # a refused close keeps the failed state and resources
-        with pytest.raises(RuntimeError, match="active CUDA"):
-            sim.close()
-    assert sim._failed is not None and sim.bodies is not None and not sim._closed
-    sim.close()  # retry outside the activation succeeds
-    assert sim._closed and sim._failed is not None
-    with pytest.raises(RuntimeError, match="CUDA context is closed"):  # no re-entry after close
-        sim.run(1)
-    with pytest.raises(RuntimeError, match="unknown"):  # the failed circle stays refused
-        motion.record()
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
ClaudeandClaude Opus 5.5	caa573f978	test: adopt native-validated 24-target probe layout Horizontal y=56 and vertical x=38 through box 1, normal coordinates [12.5..26.125] (root128 physical). Nearest-ACTIVE mapping with deterministic tie rule (distance, finer level, smaller j, smaller i), duplicate-cell rejection, stored centers and displacements. Replaces my earlier offsets, which mapped two target pairs to the same U128 cell. U512 spacing 128/512 and root step r -> U512 step 4r unchanged. Tests: 24 unique cells per case, nested 3 L0 + 5 L1 + 4 L2 per transect, U128 max displacement 0.625. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 03:13:43 +00:00
ClaudeandClaude Opus 5.5	1e188e7419	test: signed interface-probe trace diagnostic (--probe-trace) Test-only mechanism diagnostic, no pass gates. New pinned shear_probes.py: 24 fixed root-physical points on vertical/horizontal interface-normal transects (>=8 root cells from corners), ACTIVE-leaf selection storing level/i/j/actual centers, root-sync rho/ux/uy at root steps 0-128 and 1920-2048 (U512 every 4 lattice steps), analytic residuals at actual centers, schedule/finite/600 kB validation. run_case: --probe-trace for nested U128/U512/projected d3 and twin projected d2 (not with --final-snapshot), shear_probes.py pin, probe-only steps skip metrics, five qualification samples unchanged. shear_wave/shear_nested/shear_twin/ oracle byte-identical. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 03:11:48 +00:00
ClaudeandClaude Opus 5.5	02bde0f751	test: depth-2 twin of the nested shear preset (twin_shear_n128) Test-only opt-in. New shear_twin.py: same two L0->L1 boxes as shear_nested, no L2; leaves [7936,33792], hops [2048,4096], work 154664960. Four fresh cases U128/U256/constant R128 d2/projected R128 d2; physics is the unchanged depth-2/2N shear_wave.assess. run_case: --diagnostic twin_shear_n128 with shear_twin.py+shear_nested.py pins, no snapshot. assess_shear_wave: nested contract made preset-generic (PRESETS) with nested behaviour unchanged. Labels: twin vs nested = effect of adding this nested refinement (not abstract depth). shear_wave.py, shear_nested.py and oracle.py byte-identical. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 02:52:20 +00:00
ClaudeandClaude Opus 5.5	335624c27b	test: fixed three-level/two-region nested shear preset (nested_shear_n128) Test-only opt-in. New shear_nested.py: fixed parent-frame rectangles (L0->L1 (16,16,60,112),(68,24,112,120); L1->L2 (44,44,108,212), (148,60,212,228)), exact leaves/hops/work/nu/tau, depth-3 + 4N-finest generalization of the shear assessment (same summaries/screens/budgets), bounded final macro snapshot writer/reader (packed ACTIVE leaves + rho/u, metadata, sha256, 8 MiB cap; no populations/restart/time series). run_case: --diagnostic nested_shear_n128 (U128, U512, constant/projected R128 depth 3), --final-snapshot only for projected depth 3, shear_nested.py path+hash pin. assess_shear_wave: assess_nested contract and CLI. shear_wave.py and oracle.py byte-identical; old guards/defaults unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 02:14:23 +00:00
ClaudeandClaude Opus 5.5	9748ef91ef	test: portable few-ULP check for recomputed shear eps metadata Cross-platform replay of the frozen assessor returned INVALID_SET because recomputed eps(128) differed from the Horsea receipt by one ULP. Compare only that derived float within 4 ULPs (close_ulps); hashes, case identity, other metadata and scientific thresholds stay exact. Tests accept the observed one/two-ULP differences and reject 1e-12 relative, 2x, string, NaN and missing values. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 01:15:59 +00:00
ClaudeandClaude Opus 5.5	5fb95f5f4d	test: opt-in scaled_shear_n256 four-case shear diagnostic - run_case: --diagnostic scaled_shear_n256 (requires --flow shear_wave; U256/U512/constant R256/projected R256, Re100, no early trace); N512 only via one of the two scaled diagnostics; scaled_n256 stays TG-only. - assess_shear_wave: scaled=True contract reusing `92b8afe` scaled case/build/workload checks, shear diagnostic identity; signed rate bias, refined excess over each control; hash-pinned `de5b0cc` N128 reference and descriptive N128->N256 signed trend; CLI --diagnostic/--reference-files. - tests: scaled contract, set mixing, trend/reference pin, runner options. - shear_wave.py and oracle.py unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 01:14:54 +00:00
ClaudeandClaude Opus 5.5	46100e1d53	Merge native `92b8afe` scaled N256 Taylor-Green diagnostic into claude/shear-wave Bundle celeris-scaled-tg-92b8afe-base-eec4677.bundle (SHA256 9e593384...) verified with git bundle verify; merged without rewriting history. Conflicts resolved by retaining both additions: run_case keeps the shear-wave flow helpers/receipt block and the scaled_n256 diagnostic block, with scaled_n256 restricted to --flow taylor_green (mutually exclusive with shear_wave); test_projected_pairs keeps the explicit 'taylor_green' verify_source argument and 92b8afe's per-scheme selector expectation. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 01:14:39 +00:00
ClaudeandClaude Opus 5.5	de5b0cc080	test: shear-wave modal-extinction handling; TG mock verify_source flow arg - shear_wave.fit_rate: finite late R=0 returns rate_fit_valid=false with null fit quantities (no clipping, no invented rate); own screens and budgets treat it as a failure (CONTROL_SCREEN_FAIL / refined FAIL), other finite metrics retained, JSON-safe. - test_projected_pairs: dry-run/execution mocks expect the explicit 'taylor_green' flow argument now passed to verify_source. - run_case: SHEAR_WAVE_SHA256 repinned; extinction test added. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 00:36:19 +00:00
ClaudeandClaude Opus 5.5	f337652683	test: shear-wave row validation, controlled-pass semantics, bounds - shear_wave: validate_rows before screens (exact scheduled steps/t*, no duplicates, all numeric/list fields finite, nonnegative error fields, rho_min>0; signed amplitude/phase/interval errors keep their sign); INVALID_RUN for invalid refined rows; own_screens_pass vs controlled_pass so a CONTROL_SCREEN_FAIL set never reports a controlled pass; empty or duplicate refined schemes rejected; pressure-budget redundancy stated. - run_case: SHEAR_WAVE_SHA256 repinned to the updated module. - tests: divergence/advection bounds use a(t) and the derived h^2 term; invalid-row mutations; signed errors allowed; controlled_pass checks. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 00:28:46 +00:00
ClaudeandClaude Opus 5.5	3554cb2fde	test: fix shear-wave review findings (runner finiteness, source pin, contract) - run_case: finite_row accepts list diagnostics; sample() shared by sample and READY paths; verify_source pins shear_wave.py path+SHA256 for --flow shear_wave (default TG flow unchanged, does not import it). - assess_shear_wave.py: fixed N128 four-case contract and 4-JSON CLI, reusing assess_projected_pairs provenance/build/workload/time checks plus shear metadata; missing/duplicate/mixed/extra records -> INVALID_SET. - tests: mocked refined runner sample (list diagnostics, NaN, TG unchanged), contract pass + reproduced false-pass mutations, divergence check uses analytic E.k=0 and a derived h^2 truncation + roundoff bound with h-halving scaling instead of a fixed 1e-12. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 00:26:58 +00:00
ClaudeandClaude Opus 5.5	10069feadb	test: apply shear-wave review corrections Modal magnitude R=hypot(a,b) with amplitude error and separate phase; free-intercept ln R rate fit with per-interval rates, log-fit residual, t* units and finite-positive check; spurious-pressure naming with raw rms; INVALID_CONTROL vs CONTROL_SCREEN_FAIL (refined results kept), mixed-source check, raw ratios to both controls; docs narrow the cubic-term scope, startup and placement limitations. oracle.py still byte-identical. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 00:18:20 +00:00
ClaudeandClaude Opus 5.5	ffff742b69	test: add oblique (2,1) shear-wave diagnostic with composite modal fit Test-only. New shear_wave.py (exact field, equilibrium initializer reusing frozen oracle constants/geometry, area-weighted composite metrics with a 2x2 Gram-matrix modal fit, late-time rate fit, preregistered assess with max(2*control, floor) budgets). run_case.py gains --flow (default taylor_green, unchanged receipt). oracle.py byte-identical (pinned by test). CPU manufactured checks in test_shear_wave.py; docs record caveats. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-19 00:16:21 +00:00
Codex	92b8afeeed	test: add scaled N256 Taylor-Green diagnostic	2026-10-18 17:00:55 -07:00