README: several regions are refinements[0], not bounds

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -112,8 +112,9 @@ 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, (8, 6, 24, 18), context=ctx,
-                                              fine_objects=[body], fine_block=(16, 20)) as run:
+with CudaContext(0) as ctx, FixedPatchStepper(cfg, context=ctx, refinements=[(8, 6, 24, 18)],
+                                              level_blocks=[None, (16, 20)],
+                                              level_objects=[(), (body,)]) 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.patch.coarse_shape)),
@@ -133,19 +134,19 @@ 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.
-- `fine_block=(by, bx)` stores the fine level in fixed-size blocks; `by`/`bx` must
+- `level_blocks=[None, (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
-  `bounds`, with both `fine_block` and `base_block`. Transfers are built once
+  `refinements[0]`, with both levels blocked (`level_blocks`). 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.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. `fine_objects`/`jets` work
+  with tiles. Order of rectangles does not matter. L1 bodies/Jets (`level_objects[1]`/`level_jets[1]`) 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
@@ -156,8 +157,8 @@ Scope and limits:
   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, ((4, 4, 12, 12), (16, 4, 24, 12)), context=ctx,
-          fine_block=(4, 4), base_block=(4, 4)) as run:
+          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.patch.coarse_shape)),
                      np.broadcast_to(rest, (9, *run.patch.fine_shape)))  # (9, 32, 64)
       run.step(32)
@@ -166,12 +167,12 @@ Scope and limits:
   ```
 - 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
+  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 patch only. Optional stationary circles and Jets
-  live on L2 via `child_objects` and `child_jets`; `fine_objects`/`jets` retain
+  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
@@ -188,9 +189,9 @@ 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, (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:
+          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.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)

docs/compatibility.md

@@ -0,0 +1,35 @@
+# 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.
+
+## 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.

docs/development/root_channel_candidate.md

@@ -1,6 +1,6 @@
 # Blocked AMR root channel increment
 
-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.
+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.
 
 `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`:
 

docs/fixed_three_level_multipatch.md

@@ -16,8 +16,8 @@ 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.
 
-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
+A rectangle list as the second `refinements` entry (formerly the keyword
+`child_rectangles_in_parent=[...]`) 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`:
@@ -47,9 +47,9 @@ tile edges.
 
 ```python
 run = FixedPatchStepper(
-    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)],
+    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,
 )
 ```
 
@@ -57,7 +57,7 @@ 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 `child_objects` and `child_jets` use root edge
+Stationary whole-circle L2 bodies and Jets (`level_objects[2]`, `level_jets[2]`) 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

docs/validation/dfg_re20.md

@@ -0,0 +1,49 @@
+# 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`.

docs/validation/refined_dfg_window.md

@@ -56,3 +56,62 @@ 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.

docs/validation/taylor_green.md

@@ -159,303 +159,3 @@ 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.

examples/fixed_patch_circle.py

@@ -90,8 +90,8 @@ def main():
     # 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, BOUNDS, context=context, coarse_boundary=args.mode,
-            fine_objects=[body], fine_block=fine_block) as run:
+            cfg, context=context, coarse_boundary=args.mode, refinements=[BOUNDS],
+            level_blocks=[None, fine_block], level_objects=[(), (body,)]) 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.

examples/fixed_patch_jet.py

@@ -148,8 +148,8 @@ def main():
                   samples=[], status='running', last_synchronized_coarse_step=0)
     start, run = time.monotonic(), None
     try:
-        with CudaContext(0) as context, FixedPatchStepper(cfg, BOUNDS, context=context,
-                coarse_boundary='slot_reservoir') as run:
+        with CudaContext(0) as context, FixedPatchStepper(cfg, context=context,
+                coarse_boundary='slot_reservoir', refinements=[BOUNDS]) as run:
             p = run.patch
             masks = [np.ones(p.coarse_shape, bool), p.fine_kind == ACTIVE]
             masks[0][[0, -1]] = False

examples/fixed_periodic_patch.py

@@ -48,7 +48,7 @@ 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, PeriodicPatchStepper(cfg, (4, 4, 12, 12), context=context) as run:
+    with CudaContext(0) as context, PeriodicPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)]) 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)

src/CelerisLab/body/jets.py

@@ -216,11 +216,8 @@ def surface_link_velocity(objects, cfg, flags, fluid_idx, dir, body_id, rx, ry,
     enabled = [obj for obj in objects if obj.surface_actuation is not None]
     if not enabled and not jets:
         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")
+    from .preprocess.flag_overlay import validate_cut_link_ownership
+    validate_cut_link_ownership(flags, fluid_idx, dir, cfg.nq)
     surface_velocity = np.zeros((len(dir), 2), np.float32)
     surface_aperture = np.zeros(len(dir), bool)
     for obj in enabled:

src/CelerisLab/body/manager.py

@@ -27,7 +27,7 @@ import pycuda.driver as cuda
 
 from .objects import SimObject
 from .registry import BodyRegistry
-from .preprocess.flag_overlay import merge_flag_masks
+from .preprocess.flag_overlay import merge_flag_masks, validate_cut_link_ownership
 from ..cuda.compiler_v2 import obs_layout
 from ..cuda.obs_layout import ObsLayout
 from ..lbm.descriptors import (
@@ -369,9 +369,9 @@ class ObjectManager:
 
         Args:
             objects: List of SimObject instances to process.
-            domain_flags: Optional uint16 flags for donor-cell classification.
+            domain_flags: Optional uint16 flags for receiver/donor classification.
             sensor_cell_counts_out: Int array to fill with per-object sensor
-                cell counts.  If provided, ``fill(0)`` is called first.
+                cell counts after the full geometry has passed validation.
             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()
 
-        if sensor_cell_counts_out is not None:
-            sensor_cell_counts_out.fill(0)
+        sensor_counts = (np.zeros_like(sensor_cell_counts_out)
+                         if sensor_cell_counts_out is not None else None)
 
         ez = None
         if self.cfg and self.cfg.is_d3q19:
@@ -430,9 +430,9 @@ class ObjectManager:
                 if len(cells) > 0:
                     s_cells.append(cells)
                     s_ids.append(ids)
-                    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 (sensor_counts is not None
+                            and 0 <= obj.obj_id < sensor_counts.size):
+                        sensor_counts[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]
@@ -461,8 +461,9 @@ 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))
-        if hits_out is not None:
-            hits_out.append(r_hit)
+        # 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 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
@@ -470,6 +471,11 @@ 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,
@@ -487,8 +493,6 @@ 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 = []
 
@@ -499,6 +503,7 @@ 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()

src/CelerisLab/body/preprocess/flag_overlay.py

@@ -1,6 +1,6 @@
 # CelerisLab/body/preprocess/flag_overlay.py
 """
-Flag overlay: merge per-object flag masks onto a clean domain base.
+Flag overlay and cut-link ownership checks against the merged domain.
 """
 
 from __future__ import annotations
@@ -12,6 +12,15 @@ 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],

src/CelerisLab/lbm/block_stepper.py

@@ -204,11 +204,21 @@ class PeriodicBlockStepper:
                 raise
 
     def step(self, n=1):
-        """Advance n steps: halo refresh, then core pull/collide, per step."""
+        """Advance n steps: halo refresh, then core pull/collide, per step.
+
+        All n steps are enqueued in order on the one stream and the host waits
+        once before returning (same launches and bits as n step(1) calls).
+        Asynchronous device errors surface at that single wait, so they are not
+        attributed to the step that caused them; call step(1) repeatedly to
+        localize one. On any failure the instance is failed and step_count keeps
+        its entry value.
+        """
         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")
+            if n == 0:
+                return
             kw = dict(block=self._block, stream=self._stream)
             try:
                 self._status = "advancing"
@@ -224,9 +234,9 @@ class PeriodicBlockStepper:
                     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._current, self._spare = self._spare, self._current  # host handles only
+                self._stream.synchronize()
+                self._step_count += n
                 self._status = "ready"
             except BaseException:
                 self._status = "failed"

src/CelerisLab/lbm/refinement_stepper.py

@@ -65,52 +65,8 @@ def _level_name(level):
     return ("base", "fine", "child")[level] if level < 3 else f"level {level}"
 
 
-def _legacy_levels(bounds, *, fine_block, base_block, child, child_block, child_rectangles_in_parent,
-                   fine_objects, jets, child_objects, child_jets):
-    """Normalise the original two/three-level keywords to per-level lists (original errors)."""
-    if child is not None and child_rectangles_in_parent is not None:
-        raise ValueError("child and child_rectangles_in_parent are mutually exclusive")
-    nested = child is not None or child_rectangles_in_parent is not None
-    bounds = tuple(bounds)
-    if not is_rectangle(bounds) and (fine_block is None or base_block is None):
-        raise ValueError("several patches require fine_block and base_block")
-    fine_objects, jets = tuple(fine_objects), tuple(jets)
-    child_objects, child_jets = tuple(child_objects), tuple(child_jets)
-    if not nested and (child_objects or child_jets):
-        raise ValueError("child_objects/child_jets require a nested child")
-    if base_block is not None and fine_block is None:
-        raise ValueError("base_block requires fine_block")
-    refinements, blocks = [bounds], [base_block, fine_block]
-    objects, level_jets = [(), fine_objects], [(), jets]
-    if nested:
-        if child is not None and not is_rectangle(bounds):
-            raise ValueError("scalar child requires one parent patch; use child_rectangles_in_parent")
-        if fine_block is None or base_block is None or child_block is None:
-            raise ValueError("a nested child needs fine_block, base_block and child_block")
-        if fine_objects or jets:
-            raise ValueError("a nested child supports bodies/Jets only on L2; use child_objects/child_jets")
-        refinements.append(tuple(child) if child is not None else tuple(child_rectangles_in_parent))
-        blocks.append(child_block)
-        objects.append(child_objects)
-        level_jets.append(child_jets)
-    return refinements, blocks, objects, level_jets
-
-
-def _initial_levels(level_g, coarse_g, fine_g, child_g):
-    """One tuple of per-level arrays from initialize()'s positional or legacy named form."""
-    if coarse_g is None and fine_g is None:
-        if child_g is not None and len(level_g) != 2:
-            raise TypeError("child_g needs exactly the coarse and fine arrays before it")
-        return tuple(level_g) + (() if child_g is None else (child_g,))
-    if level_g:
-        raise TypeError("pass level arrays positionally or as coarse_g/fine_g/child_g, not both")
-    if coarse_g is None or fine_g is None:
-        raise TypeError("coarse_g and fine_g are both required in the named form")
-    return (coarse_g, fine_g) + (() if child_g is None else (child_g,))
-
-
 def _check_levels(refinements, blocks, objects, jets):
-    """Candidate limits shared by the list and the legacy entry points."""
+    """Candidate limits of the level lists, checked before any device work."""
     depth = len(refinements) + 1
     if depth < 2:
         raise ValueError("at least one refinement level is required")
@@ -134,7 +90,14 @@ def _check_levels(refinements, blocks, objects, jets):
 
 
 class FixedPatchStepper:
-    """D2Q9/SRT/FP32, one unforced internal 2:1 patch in an x-periodic box.
+    """D2Q9 SRT/MRT FP32 fixed 2:1 refinement hierarchy, built from level lists.
+
+    ``refinements[l]`` gives level l+1 in level-l integer cells: one rectangle
+    (x0, y0, x1, y1) (FixedPatch2D, a fine window with its own origin) or a
+    sequence of rectangles (FixedPatchSet2D, a dependency-validated union on one
+    level-wide grid, public fine arrays (2*ny, 2*nx), NaN outside ACTIVE cells);
+    see lbm.hierarchy. ``level_blocks``, ``level_objects`` and ``level_jets``
+    hold one entry per level, L0 included (L0 bodies/Jets are not supported).
 
     ``coarse_boundary`` is ``periodic`` (default) or ``slot_reservoir``:
     a bottom on-site slot and top fixed-density reservoir from ``cfg``.
@@ -145,68 +108,53 @@ class FixedPatchStepper:
     actual channel closure footprint. Channel remapping is not supported.
     Periodic mode does not apply the wall/slot boundary fields in ``cfg``.
     Outer walls remain coarse; fine halo donors must be ordinary fluid.
-    ``fine_objects`` accepts fixed circles in coarse physical coordinates;
-    velocities are in coarse lattice units (dx=dt=1). Independent local copies
-    are projected at fine cell centers. Their complete stencil must be active
-    and disjoint from the actual two-hop transfer footprint.
-    These use the edge/cell-center frame (coarse centers I+.5), whereas ordinary Simulation objects use the integer-node frame.
 
-    ``initialize(coarse_g, fine_g)`` accepts physical Q-major (9,ny,nx) arrays
-    already in postcollision phase. It does not collide or build channel flags.
-    Every ``step()`` publishes only after both levels complete on one stream.
-    On a device/launch failure the instance becomes unusable: close and recreate
-    it, rather than pretending the partially advanced fine buffer rolled back.
+    Bodies are fixed circles in root (L0) physical coordinates; velocities are
+    in root lattice units (dx=dt=1). Independent local copies are projected at
+    fine cell centers; their complete stencil must be active and disjoint from
+    the actual two-hop transfer footprint. These use the edge/cell-center frame
+    (coarse centers I+.5), whereas ordinary Simulation objects use the
+    integer-node frame. Jets (body.jets.Jet) use the same frame and drive cut
+    links selected at their true hits; ``set_jet_amplitude(index, amplitude,
+    level=l)`` re-uploads the per-link velocity column only.
+
+    ``initialize(*level_g)`` accepts one physical Q-major (9, ny, nx) array per
+    level, already in postcollision phase. It does not collide or build channel
+    flags. Every ``step()`` publishes only after all levels complete on one
+    stream. On a device/launch failure the instance becomes unusable: close and
+    recreate it, rather than pretending a partially advanced buffer rolled back.
+
+    A ``level_blocks`` entry (by, bx) stores that level in blocks.cu storage:
+    the ENTIRE level shape, including the four-cell patch ghost band, is
+    partitioned by a non-periodic BlockLayout2D with one-cell same-level halos.
+    Patch kinds stay per cell (OUTER invalid, INNER stream only, ACTIVE
+    collide); halos are gathered before each hop. Public arrays keep the dense
+    shapes; only the allocation differs. A blocked level requires blocked
+    refined levels below it; several L1 rectangles and depth >= 3 require all
+    levels blocked. Blocked bodies are stationary circles, optionally
+    surface-actuated: prepare_fine_boundary decides legality on the dense grid,
+    then cut links are staged receiver-local per hop: halo -> BFL -> step, same
+    buffer. A blocked parent gathers halos before receiver-local coalescence
+    staging and pull/collision; covered cells are poisoned on every step.
 
-    ``fine_block=(by, bx)`` (opt-in) stores the fine level in
-    blocks.cu storage: the ENTIRE fine_shape, including the four-cell patch
-    ghost band, is partitioned by a non-periodic BlockLayout2D with one-cell
-    same-level halos. Patch kinds stay per cell (OUTER invalid, INNER stream
-    only, ACTIVE collide); halos are gathered before each fine hop. Public
-    arrays keep the dense (9, ny, nx) fine shape; only the allocation differs.
-    Blocked fine_objects are stationary circles, optionally surface-actuated:
-    prepare_fine_boundary decides legality on the dense fine grid, then cut
-    links are staged receiver-local per hop: halo -> BFL -> step, same buffer.
-    ``base_block=(by, bx)`` also blocks the parent; it requires ``fine_block``.
-    Parent halos precede receiver-local coalescence staging and pull/collision;
-    covered cells are explicitly poisoned on every step. Public shapes stay dense.
     ``observe_raw_exchange=True`` records blocked physical cut-link exchange
     without changing populations. read_raw_exchange reports the last complete
     base interval or last substep in base-lattice units per unit depth. This
     is boundary momentum reaction, not a validated nozzle/stress load. Dense
-    body layouts are not supported by this new diagnostic in this candidate.
+    body levels are not supported by this diagnostic.
     ``observe_window_exchange=True`` (requires observe_raw_exchange) adds a second
     per-link FP64 ledger accumulated by the same kernel between
     start_exchange_window() and read_exchange_window(); disabled by default.
-    ``jets`` (body.jets.Jet) use the same edge frame as ``fine_objects`` and
-    drive fine cut links selected at their true hits; ``set_jet_amplitude``
-    re-uploads the per-link velocity column only.
 
-    Several patches: pass ``bounds`` as a sequence of (x0, y0, x1, y1)
-    rectangles (FixedPatchSet2D, dependency-validated union). This requires
-    fine_block and base_block; fine_objects/jets are projected once onto the
-    level-wide fine grid (each circle inside the union, body ids = object
-    positions, jet and writer checks level-wide), and
-    uses one level-wide fine grid (2*ny, 2*nx): public fine arrays have that
-    shape, NaN outside the patches' ACTIVE cells. The step sequence is the
-    blocked one above, with unique union transfers in one launch each.
-
-    Three-level separated unions: ``child_rectangles_in_parent=[...]`` is
-    mutually exclusive with scalar ``child`` and accepts either parent form.
-    Coordinates index the allocated L1 array, including ghost bands and holes:
-    root edge = patch.fine_origin + L1 index / 2. A parent set has origin zero;
-    a scalar parent retains its shifted window origin. The child set's public
-    extent is twice the allocated L1 shape, even though storage is sparse.
-    Each pair requires gap >= 4 in its own parent-cell units. All regions share
-    one buffer pair per level and the fixed 1:2:4 schedule; L2-only bodies/Jets
-    below apply unchanged, with object IDs assigned over the whole level.
-
-    Three-level single chain: ``child`` bounds use L1 window cells; all three
-    levels must be blocked. ``child_objects`` and ``child_jets`` use the L0
-    edge frame, with L2 dx=dt=.25 and unchanged lattice velocity. L1 bodies
-    and Jets remain unsupported in a chain. Every whole circle and its BFL
-    stencil must fit strictly away from the L2 transfer footprint. L2 runs
-    halo -> BFL -> step four times per base step. Runtime child Jet changes
-    require ``set_jet_amplitude(index, amplitude, level=2)``.
+    Nested levels: a child set's coordinates index the allocated parent array,
+    including ghost bands and holes: root edge = parent fine_origin + index / 2
+    (zero origin for a parent set; a scalar parent keeps its shifted window
+    origin). A scalar child requires a scalar parent. Each pair requires gap >= 4
+    in its own parent-cell units. All regions share one buffer pair per level
+    and the fixed schedule of 2**l hops per base step at level l. Bodies/Jets are supported only on the
+    finest level of a nested hierarchy (L2 dx=dt=.25 in root units, unchanged
+    lattice velocity); every whole circle and its BFL stencil must fit strictly
+    away from that level's transfer footprint.
 
     ``explosion="projected_linear"`` selects experimental transverse linear
     reconstruction on each adjacent pair. Default "constant" is unchanged.
@@ -214,43 +162,21 @@ class FixedPatchStepper:
     bodies/Jets or LES; this backend supplies no forcing. Geometry is generic,
     but union/multilevel GPU and matched-physics qualification remain pending.
 
-    Level lists (any depth): ``refinements[l]`` gives level l+1 in level-l
-    integer cells (scalar window or rectangle list, see lbm.hierarchy);
-    ``level_blocks``/``level_objects``/``level_jets`` hold one entry per level,
-    L0 included. They are mutually exclusive with the legacy keywords above,
-    which are normalised to the same lists. One recursive hop advances every
-    level: a child explodes from its parent's current hop source, takes two
-    hops, then the parent gathers halos, stages restriction, applies BFL and
-    steps. Depth >= 3 must be fully blocked with bodies/Jets on the finest level.
+    One recursive hop advances every level: a child explodes from its parent's
+    current hop source, takes two hops, then the parent gathers halos, stages
+    restriction, applies BFL and steps.
     """
-    def __init__(self, cfg, bounds=None, *, context, coarse_boundary="periodic", fine_objects=(),
-                 fine_block=None, base_block=None, jets=(), child=None, child_block=None,
-                 child_objects=(), child_jets=(), child_rectangles_in_parent=None,
-                 refinements=None, level_blocks=None, level_objects=None, level_jets=None,
+    def __init__(self, cfg, *, context, refinements, coarse_boundary="periodic",
+                 level_blocks=None, level_objects=None, level_jets=None,
                  observe_raw_exchange=False, observe_window_exchange=False, explosion="constant"):
         if HALO != 4:
             raise RuntimeError("refinement.cu requires a four-cell fine halo")
         if coarse_boundary not in ("periodic", "slot_reservoir", "channel"):
             raise ValueError("coarse_boundary must be periodic, slot_reservoir or channel")
-        if refinements is None:
-            if bounds is None:
-                raise ValueError("bounds or refinements is required")
-            if level_blocks is not None or level_objects is not None or level_jets is not None:
-                raise ValueError("level_blocks/level_objects/level_jets require refinements")
-            refinements, level_blocks, level_objects, level_jets = _legacy_levels(
-                bounds, fine_block=fine_block, base_block=base_block, child=child,
-                child_block=child_block, child_rectangles_in_parent=child_rectangles_in_parent,
-                fine_objects=fine_objects, jets=jets, child_objects=child_objects,
-                child_jets=child_jets)
-        else:
-            if (bounds is not None or child is not None or child_rectangles_in_parent is not None
-                    or fine_block is not None or base_block is not None or child_block is not None
-                    or tuple(fine_objects) or tuple(jets) or tuple(child_objects) or tuple(child_jets)):
-                raise ValueError("refinements and the legacy patch keywords are mutually exclusive")
-            depth = len(refinements) + 1
-            level_blocks = [None] * depth if level_blocks is None else list(level_blocks)
-            level_objects = [()] * depth if level_objects is None else list(level_objects)
-            level_jets = [()] * depth if level_jets is None else list(level_jets)
+        depth = len(refinements) + 1
+        level_blocks = [None] * depth if level_blocks is None else list(level_blocks)
+        level_objects = [()] * depth if level_objects is None else list(level_objects)
+        level_jets = [()] * depth if level_jets is None else list(level_jets)
         level_objects = [tuple(o) for o in level_objects]
         level_jets = [tuple(j) for j in level_jets]
         level_blocks = [None if b is None else tuple(b) for b in level_blocks]
@@ -540,13 +466,13 @@ class FixedPatchStepper:
         if self._ddf_shifting and any(layout is None for layout in self._layouts):
             raise ValueError("shifted populations require all-blocked levels")
 
-    def initialize(self, *level_g, coarse_g=None, fine_g=None, child_g=None):
+    def initialize(self, *level_g):
         """Upload physical postcollision G, encoding before any FP32 rounding.
 
         Shifted input should be physical FP64 to retain small perturbations.
         Public initialization resets the step count; non-leaves are discarded.
         """
-        given = _initial_levels(level_g, coarse_g, fine_g, child_g)
+        given = tuple(level_g)
         with self._lock, self.ctx.activate():
             self._require("new", "ready")
             self._check_storage()
@@ -670,10 +596,9 @@ class FixedPatchStepper:
                 old, new, source, base_count=count, level_steps=(count, 2*count, 4*count),
                 phase="postcollision_g", **options)
             candidate = type(self)(
-                cfg, pairs[0].bounds, context=self.ctx, base_block=base_block,
-                fine_block=fine_block, child_block=child_block,
-                child_rectangles_in_parent=new.child.bounds,
-                child_objects=child_objects, child_jets=jets,
+                cfg, context=self.ctx, refinements=[pairs[0].bounds, new.child.bounds],
+                level_blocks=[base_block, fine_block, child_block],
+                level_objects=[(), (), child_objects], level_jets=[(), (), jets],
                 observe_raw_exchange=self._observe_raw_exchange,
                 observe_window_exchange=self._observe_window, explosion=self._explosion)
             try:
@@ -822,27 +747,41 @@ class FixedPatchStepper:
                             grid=((pairs + self._block[0] - 1) // self._block[0], 1), **kw)
 
     def step(self, n=1):
-        """Advance G→G by n base intervals: level l takes 2**l hops per interval."""
+        """Advance G→G by n base intervals: level l takes 2**l hops per interval.
+
+        All n intervals are enqueued in order on the one stream, and the host waits
+        once, before returning; step(0) launches and waits for nothing. On return
+        the device work is complete, step_count and an open window cover all n
+        intervals, and the raw-exchange ledger holds the final interval only.
+
+        Asynchronous device errors surface at that single wait, so they are not
+        attributed to the interval that caused them; call step(1) repeatedly to
+        localize one (same launches, same bits). On any failure the instance is
+        failed, the exchange ledger and window are invalid, and step_count keeps
+        its value from entry to the failing call.
+        """
         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")
+            if n == 0:
+                return
             root = self._levels[0]
             kw = dict(block=self._block, stream=self._stream)
             try:
                 self._status = "advancing"
+                self._exchange_valid = False
                 for _ in range(n):
-                    if self._observe_raw_exchange:
-                        self._exchange_valid = False
+                    if self._observe_raw_exchange:  # stream-ordered: holds the last interval only
                         for b in self._level_boundaries:
                             if b is not None:
                                 cuda.memset_d8_async(b.interval_integral, 0,
                                                      len(b.tables["cell"]) * 32, self._stream)
                     self._hop(0, root.current, root.spare, **kw)
-                    self._stream.synchronize()
-                    root.current, root.spare = root.spare, root.current
-                    self._step_count += 1
-                    self._exchange_valid = self._observe_raw_exchange
+                    root.current, root.spare = root.spare, root.current  # host handles only
+                self._stream.synchronize()
+                self._step_count += n
+                self._exchange_valid = self._observe_raw_exchange
                 self._status = "ready"
             except BaseException:
                 self._window_valid = False

src/CelerisLab/simulation.py

@@ -336,13 +336,19 @@ 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.
         """
-        if self.bodies.get(id).surface_actuation is None:
+        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:
             raise ValueError("Body has no surface actuation")
         self.stream.synchronize()
-        return self.field.curved.surface_exchange(id)
+        return curved.surface_exchange(id)
 
     @context_bound
     def read_body(self, id: int, *,
@@ -451,18 +457,21 @@ class Simulation:
     @context_bound
     def initialize(self):
         """Initialize flow field and sync objects to GPU."""
-        # Recompile if objects were added after construction.
         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())
+        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.
         if self._read_generated_n_objects() != self.bodies.count:
             self.recompile()
 
-        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.flag = next_flags
         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)

tests/unit/test_block_step_sync.py

@@ -0,0 +1,102 @@
+"""Host contract of PeriodicBlockStepper.step(n): one stream wait per call (mocked driver)."""
+import ast
+from contextlib import nullcontext
+from pathlib import Path
+import types
+from unittest.mock import Mock
+import unittest
+
+import numpy as np
+
+import CelerisLab.lbm.block_stepper as b
+from CelerisLab.config import LBMConfig
+from CelerisLab.lbm.blocks import BlockLayout2D
+
+
+def host_module():
+    """block_stepper with pycuda/compiler replaced by mocks; no GPU context."""
+    path = Path(b.__file__)
+    tree = ast.parse(path.read_text())
+    tree.body = [node for node in tree.body if not (
+        isinstance(node, ast.Import) and any(a.name == "pycuda.driver" for a in node.names)
+        or isinstance(node, ast.ImportFrom) and node.module == "cuda")]
+    module = types.ModuleType("CelerisLab.lbm._test_host_block_stepper")
+    module.__package__ = "CelerisLab.lbm"
+    module.__dict__.update(cuda=Mock(), compiler=Mock())
+    exec(compile(tree, str(path), "exec"), module.__dict__)
+    return module
+
+
+def backend():
+    host, log = host_module(), []
+    host.cuda.mem_get_info.return_value = (1 << 40, 1 << 40)
+    host.cuda.mem_alloc.side_effect = lambda size: Mock(size=size)  # distinct buffers
+    module = Mock()
+    module.get_global.return_value = (Mock(), 20)
+    module.get_function.side_effect = lambda name: Mock(
+        side_effect=lambda *a, **k: log.append((name, a[:2])))
+    host.compiler.load_module.return_value = module
+    cfg = LBMConfig(nx=16, ny=16, viscosity=.1)
+    run = host.PeriodicBlockStepper(cfg, BlockLayout2D.build(16, 16, 8, 8),
+                                    context=Mock(activate=nullcontext, sm_arch="sm_70"))
+    run._stream.synchronize.side_effect = lambda: log.append(("sync", ()))
+    run.initialize(np.full((9, 16, 16), 1 / 9))
+    log.clear()
+    return run, log
+
+
+class BlockStepSync(unittest.TestCase):
+    def test_step_n_waits_once_and_matches_n_single_steps(self):
+        many, log_many = backend()
+        many.step(3)
+        single, log_single = backend()
+        for _ in range(3):
+            single.step(1)
+        names = [name for name, _ in log_many]
+        self.assertEqual(names.count("sync"), 1)
+        self.assertEqual(names[-1], "sync")
+        self.assertEqual(names.count("BlockStep"), 3)
+        # Same launch order and buffer roles as three step(1) calls.
+        strip = lambda log: [(n, tuple(id(x) for x in a)) for n, a in log if n != "sync"]
+        roles = lambda run, log: [(n, tuple({id(run._current): "c", id(run._spare): "s"}.get(x, "-")
+                                            for x in ids)) for n, ids in strip(log)]
+        self.assertEqual([n for n, _ in strip(log_many)], [n for n, _ in strip(log_single)])
+        self.assertEqual(roles(many, log_many), roles(single, log_single))
+        self.assertIsNot(many._current, many._spare)
+        self.assertEqual((many.step_count, single.step_count), (3, 3))
+
+    def test_step_zero_launches_and_waits_for_nothing(self):
+        run, log = backend()
+        run.step(0)
+        self.assertEqual((log, run.step_count), ([], 0))
+
+    def test_failure_keeps_entry_step_count(self):
+        run, log = backend()
+        run.step(1)
+        run._stream.synchronize.side_effect = RuntimeError("device fault")
+        with self.assertRaises(RuntimeError):
+            run.step(2)
+        self.assertEqual((run.step_count, run._status), (1, "failed"))
+
+    def test_launch_failure_mid_batch_fails_closed_without_waiting(self):
+        run, log = backend()
+        calls = []
+        step = run._step
+
+        def failing(*args, **kwargs):
+            calls.append(1)
+            if len(calls) == 2:
+                raise RuntimeError("launch failure")
+            return step(*args, **kwargs)
+
+        run._step = failing
+        with self.assertRaises(RuntimeError):
+            run.step(3)
+        self.assertNotIn("sync", [name for name, _ in log])
+        self.assertEqual((run.step_count, run._status), (0, "failed"))
+        with self.assertRaises(RuntimeError):
+            run.download()
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/unit/test_channel_root.py

@@ -80,8 +80,8 @@ def test_evolved_ghost_snapshot_and_physical_download():
     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, (6, 6, 18, 14), context=context,
-                                    coarse_boundary="channel", base_block=(4, 6), fine_block=(4, 4))
+    backend = host.FixedPatchStepper(cfg, context=context, coarse_boundary="channel",
+                                    refinements=[(6, 6, 18, 14)], level_blocks=[(4, 6), (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]

tests/unit/test_dfg_re20.py

@@ -0,0 +1,79 @@
+"""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()

tests/unit/test_jet_circle_cv.py

@@ -16,6 +16,7 @@ from run_jet_circle_cv import (
     case,
     state,
     cv,
+    cv_from_macros,
     aperture_probe,
     measured_aperture_flux,
     verify,
@@ -28,6 +29,39 @@ 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
 

tests/unit/test_jets.py

@@ -188,6 +188,55 @@ 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))
+    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))
+    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)

tests/unit/test_raw_exchange.py

@@ -157,8 +157,9 @@ class RawExchange(unittest.TestCase):
         host = host_module()
         ctx = Mock()
         with self.assertRaisesRegex(ValueError, 'blocked body'):
-            host.FixedPatchStepper(LBMConfig(nx=32, ny=32, viscosity=.1), (4, 4, 28, 28),
-                                   context=ctx, fine_objects=[body(radius=2.15)], observe_raw_exchange=True)
+            host.FixedPatchStepper(LBMConfig(nx=32, ny=32, viscosity=.1), context=ctx,
+                                   refinements=[(4, 4, 28, 28)],
+                                   level_objects=[(), (body(radius=2.15),)], observe_raw_exchange=True)
         ctx.activate.assert_not_called()
 
     def test_all_depth_weights(self):

tests/unit/test_refined_dfg.py

@@ -146,23 +146,26 @@ def test_full_requires_completed_pilot():
         r.verify_pilot(None, r.verify_source(r.DEFAULT_SOURCE, "MRT", "window"))
 
 
-def pilot_fixture(path, observation_mode="window"):
+def pilot_fixture(path, observation_mode="window", jet_scenario="none", case_selection="both", uniform_diameter=80, placement="wide"):
     """Synthetic contract fixture only; never a physical result or run receipt."""
-    manifest = (r.verify_source(r.DEFAULT_SOURCE, "MRT", "window")
+    manifest = (r.verify_source(r.DEFAULT_SOURCE, "MRT", "window", jet_scenario)
                 if observation_mode == "window" else
                 json.loads((r.HERE / "data/refined_dfg/source_manifest_mrt.json").read_text()))
+    selection = dict(case_selection=case_selection, uniform_diameter=uniform_diameter, placement=placement)
     (path / "plan.json").write_text(
         json.dumps(
             dict(
                 source_manifest=manifest,
+                **selection,
                 collision="MRT",
+                jet_scenario=jet_scenario,
                 observation_mode=observation_mode,
-                bounds_root_edge=list(r.BOUNDS),
+                bounds_root_edge=list(r.PLACEMENTS[placement]),
                 runner_sha256=r.runner_hash(),
             )
         )
     )
-    for case, diameter in (("uniform", 80), ("refined", 40)):
+    for case, diameter in r.selected_cases(case_selection, uniform_diameter):
         dest = path / case
         dest.mkdir()
         interval = round(0.02 * diameter / r.SPEED)
@@ -189,7 +192,9 @@ def pilot_fixture(path, observation_mode="window"):
             json.dumps(
                 dict(
                     case=case,
+                    **selection,
                     collision="MRT",
+                    jet_scenario=jet_scenario,
                     observation_mode=observation_mode,
                     mode="pilot",
                     status="pilot_complete",
@@ -206,7 +211,9 @@ def pilot_fixture(path, observation_mode="window"):
             json.dumps(
                 dict(
                     case=case,
+                    **selection,
                     collision="MRT",
+                    jet_scenario=jet_scenario,
                     observation_mode=observation_mode,
                     mode="pilot",
                     step=interval,
@@ -451,6 +458,169 @@ def test_window_contract_rejection():
     assert not backend.events
 
 
+def test_public_jet_configuration_and_geometry():
+    for diameter, center, radius in ((40, (80.5, 81), 20), (80, (160, 160.5), 40)):
+        cfg, _, _ = r.config(h, diameter, "MRT", "fixed")
+        assert not cfg["method"]["ddf_shifting"] and not cfg["method"]["les"]["enabled"]
+        jets = r.public_jets(center, radius, "fixed")
+        assert [j.amplitude for j in jets] == [.001, -.001]
+        assert all(j.field.inward is False and j.profile == "parabolic" for j in jets)
+        assert all(j.region.r_max == radius * 1.005 for j in jets)
+        assert all(j.amplitude == 0 for j in r.public_jets(center, radius, "zero"))
+    cfg, _, _, host = r.host_geometry(r.DEFAULT_SOURCE, h, "MRT", "fixed")
+    assert not cfg.ddf_shifting and len(host.boundary_cells) > 0
+    assert r.public_jets((0, 0), 1, "none") == ()
+    with unittest.TestCase().assertRaises(ValueError):
+        r.config(h, 40, "SRT", "fixed")
+
+
+def test_public_jet_reversal_boundary_and_windows():
+    from types import SimpleNamespace
+
+    calls = []
+    handle = SimpleNamespace(set_jet_amplitude=lambda i, a: calls.append((i, a)))
+    for diameter in (40, 80):
+        boundary = round(250 * diameter / r.SPEED)
+        assert r.jet_interval(handle, "fixed", boundary - 3, 80, diameter) == (3, None)
+        switch = round(300 * diameter / r.SPEED)
+        assert r.jet_interval(handle, "reverse", switch - 3, 80, diameter) == (3, None)
+        assert not calls
+        n, event = r.jet_interval(handle, "reverse", switch, 80, diameter)
+        assert n == 80 and event["step"] == switch and event["tstar"] == 300
+        assert calls == [(0, -.001), (1, .001)]
+        calls.clear()
+        assert r.jet_interval(handle, "reverse", switch + 80, 80, diameter) == (80, None)
+        assert r.jet_interval(handle, "fixed", switch, 80, diameter) == (80, None)
+        assert not calls
+    rows = [dict(tstar=t, tstar_force=t - .5, cd=2.0, cl=-.1) for t in range(251, 306)]
+    windows = r.jet_diagnostics(rows, "reverse")
+    assert len(windows) == 6 and all(w["complete"] for w in windows)
+    assert all(w["cd"]["mean"] == 2 and np.isclose(w["cl"]["mean"], -.1) for w in windows)
+    assert windows[-1]["covered_tstar"] == 5
+    with unittest.TestCase().assertRaisesRegex(ValueError, "crosses"):
+        r.jet_diagnostics([dict(tstar=250.5, tstar_force=250, cd=1, cl=0)], "fixed")
+    assert r.plan(h, "MRT", "window", "reverse")["modes"]["full_tstar"] == 305
+
+
+def test_public_jet_source_and_pilot_separation():
+    from tempfile import TemporaryDirectory
+
+    with TemporaryDirectory() as tmp:
+        path = Path(tmp)
+        manifest = pilot_fixture(path, jet_scenario="fixed")
+        assert manifest["source_capture"].startswith("current checkout")
+        assert len(manifest["checkout_revision"]) == 40
+        assert r.verify_pilot(path, manifest, "MRT", "window", "fixed") == 3606.0
+        for scenario in ("none", "zero", "reverse"):
+            with unittest.TestCase().assertRaisesRegex(ValueError, "Jet scenario"):
+                r.verify_pilot(path, manifest, "MRT", "window", scenario)
+        for relative in ("uniform/summary.json", "refined/ready.json"):
+            receipt = path / relative
+            record = json.loads(receipt.read_text())
+            receipt.write_text(json.dumps(dict(record, jet_scenario="zero")))
+            with unittest.TestCase().assertRaises(ValueError):
+                r.verify_pilot(path, manifest, "MRT", "window", "fixed")
+            receipt.write_text(json.dumps(record))
+    with unittest.TestCase().assertRaises(ValueError):
+        r.verify_source(r.DEFAULT_SOURCE, "MRT", "last_base_step", "fixed")
+
+
+def test_cv_snapshot_common_units_and_window_endpoints():
+    records = []
+    for refined, shape, origin, diameter, impulse in (
+        (True, (240, 568), (38., 22.), 40, [4., -8.]),
+        (False, (330, 1761), (.25, .5), 80, [16., -32.]),
+        (False, (658, 3521), (.375, .75), 160, [64., -128.]),
+    ):
+        rho, ux, uy, fluid = np.ones(shape), np.full(shape, .01), np.zeros(shape), np.ones(shape, bool)
+        begin, n = round(290*diameter/r.SPEED), round(.02*diameter/r.SPEED)
+        record = r.cv_snapshot(rho, ux, uy, fluid, origin, refined, begin, n, diameter, impulse)
+        records.append(record)
+        np.testing.assert_allclose(record["outward_flux"], 0, atol=1e-12)
+        assert r.cv_selected(begin, diameter, "full") and not r.cv_selected(begin-n, diameter, "full")
+        end = round(300*diameter/r.SPEED)
+        assert r.cv_selected(end, diameter, "full") and not r.cv_selected(end+n, diameter, "full")
+        assert r.cv_selected(n, diameter, "pilot")
+        assert sum(r.cv_selected(step, diameter, "full") for step in range(begin-n, end+n+1, n)) == 501
+    for key in ("time_root", "interval_start_root", "interval_dt_root", "interval_impulse_root", "inventory"):
+        for record in records[1:]:
+            np.testing.assert_allclose(records[0][key], record[key], rtol=0, atol=1e-10)
+    assert records[0]["interval_dt_root"] == 80 and np.isclose(records[0]["tstar"], 290.02)
+    np.testing.assert_array_equal(records[0]["interval_impulse_root"], [4, -8])
+
+
+def test_cv_pilot_mode_and_helper_provenance():
+    from tempfile import TemporaryDirectory
+
+    manifest = r.verify_source(r.DEFAULT_SOURCE, "MRT", "window", "fixed", True)
+    assert "tests/validation/run_jet_circle_cv.py" in manifest["sha256"]
+    with TemporaryDirectory() as tmp:
+        path = Path(tmp)
+        old = pilot_fixture(path, jet_scenario="fixed")
+        with unittest.TestCase().assertRaisesRegex(ValueError, "CV observation mode"):
+            r.verify_pilot(path, old, "MRT", "window", "fixed", True)
+        for relative in ("plan.json", "uniform/summary.json", "refined/summary.json",
+                         "uniform/ready.json", "refined/ready.json"):
+            file = path / relative
+            record = json.loads(file.read_text())
+            record.update(observe_cv=True, cv_samples=250)
+            if relative == "plan.json":
+                record["source_manifest"] = manifest
+            file.write_text(json.dumps(record))
+        assert r.verify_pilot(path, manifest, "MRT", "window", "fixed", True) == 3606
+
+
+def test_compact_geometry_and_cv_stencils():
+    from CelerisLab.lbm.refinement import ACTIVE
+    from CelerisLab.lbm.descriptors import SOLID
+
+    _, pair, _, host = r.host_geometry(r.DEFAULT_SOURCE, h, "MRT", "fixed", "compact")
+    assert pair.fine_shape == (168, 168) and tuple(pair.fine_origin) == (46, 46)
+    fluid = (pair.fine_kind == ACTIVE) & ((host.flags.reshape(pair.fine_shape) & SOLID) == 0)
+    rho, ux, uy = np.ones(pair.fine_shape), np.full(pair.fine_shape, .01), np.zeros(pair.fine_shape)
+    record = r.cv_snapshot(rho, ux, uy, fluid, pair.fine_origin, True, 1160000, 80, 40, [1, 2], "compact")
+    np.testing.assert_allclose(record["outward_flux"], 0, atol=1e-12)
+    stencil = np.zeros(pair.fine_shape, bool)
+    for rect in r.cv_contours(True, 40, "compact"):
+        x0, y0, x1, y1 = np.rint((rect - np.tile(pair.fine_origin, 2))/.5).astype(int)
+        stencil[y0-2:y1+2, x0-2:x0+2] = stencil[y0-2:y1+2, x1-2:x1+2] = True
+        stencil[y0-2:y0+2, x0-2:x1+2] = stencil[y1-2:y1+2, x0-2:x1+2] = True
+    assert fluid[stencil].all() and not stencil.ravel()[host.transfer_fine_cells].any()
+
+
+def test_d160_config_and_single_case_receipts():
+    from tempfile import TemporaryDirectory
+    from unittest.mock import patch
+
+    cfg, _, p = r.config(h, 160, "MRT", "fixed")
+    assert (p["nx"], p["ny"], p["center"], p["radius"]) == (3521, 658, [320, 320.5], 80)
+    assert p["viscosity"] == .016 and p["mean_speed"] == .01 and not cfg["method"]["ddf_shifting"]
+    assert r.uniform_origin(160) == (.375, .75)
+    np.testing.assert_array_equal(r.cv_contours(False, 160), r.CV_CONTOURS + [.125, 0, .125, 0])
+    for scenario, expected_exit in (("fixed", 0), ("zero", 2)):
+        with TemporaryDirectory() as tmp:
+            path = Path(tmp)
+            manifest = pilot_fixture(path, jet_scenario=scenario, case_selection="uniform", uniform_diameter=160)
+            assert r.verify_pilot(path, manifest, "MRT", "window", scenario, False, "uniform", 160) == 1803
+            for selection, diameter, placement in (("both", 160, "wide"), ("uniform", 80, "wide"), ("uniform", 160, "compact")):
+                with unittest.TestCase().assertRaises(ValueError):
+                    r.verify_pilot(path, manifest, "MRT", "window", scenario, False, selection, diameter, placement)
+            # Synthetic dispatch/result check: no CUDA imports or execution.
+            output = path / "full"
+            argv = ["runner", "--collision", "MRT", "--exchange-window", "--jet-scenario", scenario,
+                    "--case", "uniform", "--uniform-diameter", "160", "--mode", "full",
+                    "--pilot-results", str(path), "--output", str(output), "--max-wall-seconds", "10", "--gpu-gates-approved"]
+            result = dict(case="uniform", healthy=True, periodic=scenario == "zero", jet_diagnostic_windows=[],
+                          status="driven_diagnostics_complete" if scenario == "fixed" else "periodic",
+                          reference_comparison=dict(reference_agreement=False))
+            with patch.object(sys, "argv", argv), patch.dict(r.os.environ, CUDA_VISIBLE_DEVICES="mock-no-gpu"), \
+                    patch.object(r, "run_case", return_value=result) as run:
+                assert r.main() == expected_exit and run.call_count == 1
+            comparison = json.loads((output / "comparison.json").read_text())
+            assert comparison["matched_case_pass"] is False and "refined_vs_uniform" not in comparison
+            assert comparison["status"].startswith("single_case_")
+
+
 if __name__ == "__main__":
     suite = unittest.TestSuite(
         unittest.FunctionTestCase(fn)

tests/unit/test_refinement_three_level_multipatch.py

@@ -173,8 +173,10 @@ def bodies_and_jets(speed=.002):
     return bodies,jets
 
 
-KW=dict(base_block=(4,4),fine_block=(4,4),child_block=(4,4),
-        child_rectangles_in_parent=CHILDREN)
+def levels(parents=PARENTS,children=CHILDREN,blocks=((4,4),)*3,objects=((),(),()),jets=((),(),())):
+    """Level-list constructor keywords for the L0 set, L1 set and L2 set used here."""
+    return dict(refinements=[parents,children],level_blocks=list(blocks),
+                level_objects=list(objects),level_jets=list(jets))
 
 
 def mock_backend(*, children=CHILDREN, bodies=False, fail_compile=False, fail_upload=False):
@@ -201,9 +203,8 @@ def mock_backend(*, children=CHILDREN, bodies=False, fail_compile=False, fail_up
         module.cuda.memcpy_htod.side_effect=upload
     objects,jets=bodies_and_jets() if bodies else ((),())
     try:
-        run=module.FixedPatchStepper(CFG,PARENTS,context=context,
-            child_objects=objects,child_jets=jets,
-            **dict(KW,child_rectangles_in_parent=children))
+        run=module.FixedPatchStepper(CFG,context=context,
+            **levels(children=children,objects=((),(),objects),jets=((),(),jets)))
     except RuntimeError:
         for allocation in allocations:
             allocation.free.assert_called_once_with()
@@ -214,28 +215,29 @@ def mock_backend(*, children=CHILDREN, bodies=False, fail_compile=False, fail_up
 class ConstructorAndSchedule(unittest.TestCase):
     def test_invalid_inputs_fail_before_context_or_allocations(self):
         context=Mock()
-        cases=[dict(child=(8,8,16,16)),dict(child_rectangles_in_parent=[]),
-               dict(child_rectangles_in_parent=[(16,16,32)]),
-               dict(child_rectangles_in_parent=[(16.5,16,32,40)]),
-               dict(child_rectangles_in_parent=[(16,16,32,24),(16,27,32,55)]),
-               dict(child_rectangles_in_parent=[(40,16,48,40)]),
-               dict(child_rectangles_in_parent=[(8,16,32,40)]),
-               dict(child_block=None),dict(fine_block=None),dict(base_block=None),
-               dict(child_block=(5,4)),dict(fine_block=(5,4)),
-               dict(child_block=(4,)),dict(child_rectangles_in_parent=(16,16,32,40))]
+        b=(4,4)
+        cases=[dict(children=(8,8,16,16)),dict(children=[]),
+               dict(children=[(16,16,32)]),
+               dict(children=[(16.5,16,32,40)]),
+               dict(children=[(16,16,32,24),(16,27,32,55)]),
+               dict(children=[(40,16,48,40)]),
+               dict(children=[(8,16,32,40)]),
+               dict(blocks=(b,b,None)),dict(blocks=(b,None,b)),dict(blocks=(None,b,b)),
+               dict(blocks=(b,b,(5,4))),dict(blocks=(b,(5,4),b)),
+               dict(blocks=(b,b,(4,))),dict(children=(16,16,32,40))]
         for changes in cases:
             with self.subTest(changes=changes),self.assertRaises((ValueError,TypeError)):
-                host.FixedPatchStepper(CFG,PARENTS,context=context,**dict(KW,**changes))
+                host.FixedPatchStepper(CFG,context=context,**levels(**changes))
         with self.assertRaisesRegex(ValueError,'margin'):
-            host.FixedPatchStepper(CFG,[(1,4,20,28),(23,4,44,28)],context=context,**KW)
+            host.FixedPatchStepper(CFG,context=context,**levels(parents=[(1,4,20,28),(23,4,44,28)]))
         objects,jets=bodies_and_jets()
-        with self.assertRaisesRegex(ValueError,'only on L2'):
-            host.FixedPatchStepper(CFG,PARENTS,context=context,fine_objects=objects,**KW)
+        with self.assertRaisesRegex(ValueError,'only on the finest level'):
+            host.FixedPatchStepper(CFG,context=context,**levels(objects=((),objects,())))
         from CelerisLab.body.jets import Jet,Tube,Parallel
         spanning=Jet(Tube((10.5,14.),0.,25.,.3),Parallel(0.),amplitude=0.)
         with self.assertRaisesRegex(ValueError,'one jet'):
-            host.FixedPatchStepper(CFG,PARENTS,context=context,child_objects=objects,
-                                  child_jets=[spanning],**KW)
+            host.FixedPatchStepper(CFG,context=context,
+                                  **levels(objects=((),(),objects),jets=((),(),[spanning])))
         context.activate.assert_not_called()
         host.cuda.mem_alloc.assert_not_called()
 
@@ -313,21 +315,23 @@ class ConstructorAndSchedule(unittest.TestCase):
 
 
 
-class InitialLevels(unittest.TestCase):
-    """initialize() entry adapter: positional per-level arrays or the legacy names, never both."""
+class RemovedLegacyAPI(unittest.TestCase):
+    """The pre-level-list constructor/initialize forms are gone and fail loudly."""
 
-    def test_forms(self):
-        a, b, c = object(), object(), object()
-        f = host._initial_levels
-        self.assertEqual(f((a, b), None, None, None), (a, b))
-        self.assertEqual(f((a, b, c), None, None, None), (a, b, c))
-        self.assertEqual(f((a, b), None, None, c), (a, b, c))      # old initialize(c, f, child_g=g)
-        self.assertEqual(f((), a, b, None), (a, b))
-        self.assertEqual(f((), a, b, c), (a, b, c))
-        for args in (((a,), None, None, c), ((a, b, c), None, None, c), ((a,), a, b, None),
-                     ((), a, None, None), ((), None, b, c)):
-            with self.subTest(args=args), self.assertRaises(TypeError):
-                f(*args)
+    def test_removed_constructor_forms_raise_type_error(self):
+        import inspect
+        context = Mock()
+        with self.assertRaises(TypeError):  # positional bounds
+            host.FixedPatchStepper(CFG, PARENTS, context=context)
+        removed = dict(bounds=PARENTS, fine_block=(4, 4), base_block=(4, 4), fine_objects=(),
+                       jets=(), child=(8, 8, 16, 16), child_block=(4, 4), child_objects=(),
+                       child_jets=(), child_rectangles_in_parent=CHILDREN)
+        for name, value in removed.items():
+            with self.subTest(keyword=name), self.assertRaises(TypeError):
+                host.FixedPatchStepper(CFG, context=context, **levels(), **{name: value})
+        context.activate.assert_not_called()
+        self.assertEqual(list(inspect.signature(host.FixedPatchStepper.initialize).parameters),
+                         ["self", "level_g"])  # no coarse_g/fine_g/child_g
 
 
 if __name__=='__main__':

tests/unit/test_shifted_jets.py

@@ -54,14 +54,13 @@ class ShiftedJets(unittest.TestCase):
                 (Jet(Tube((10.,14.),0.,26.,.3),Parallel(0.)),))]
         for objects,jets in cases:
             with self.subTest(objects=len(objects),jets=len(jets)),self.assertRaises(ValueError):
-                module.FixedPatchStepper(CFG,backend.PARENTS,context=None,
-                    base_block=(4,4),fine_block=(4,4),child_block=(4,4),
-                    child_rectangles_in_parent=A,child_objects=objects,child_jets=jets)
+                module.FixedPatchStepper(CFG,context=None,refinements=[backend.PARENTS,A],
+                    level_blocks=[(4,4)]*3,level_objects=[(),(),objects],level_jets=[(),(),jets])
         for blocks in ((None,None,None),((4,4),None,(4,4))):
             with self.assertRaises(ValueError):
-                module.FixedPatchStepper(CFG,backend.PARENTS,context=None,
-                    base_block=blocks[0],fine_block=blocks[1],child_block=blocks[2],
-                    child_rectangles_in_parent=A,child_objects=(body(),),child_jets=(jet(),))
+                module.FixedPatchStepper(CFG,context=None,refinements=[backend.PARENTS,A],
+                    level_blocks=list(blocks),level_objects=[(),(),(body(),)],
+                    level_jets=[(),(),(jet(),)])
         module.cuda.mem_alloc.assert_not_called()
         module.compiler.compile_kernel.assert_not_called()
 

tests/unit/test_shifted_storage.py

@@ -129,9 +129,10 @@ class ShiftedStorage(unittest.TestCase):
     def test_dense_or_mixed_shifted_rejected_before_compilation(self):
         module=backend.host_module()
         cfg=replace(backend.CFG,ddf_shifting=True)
-        for kwargs in ({},dict(base_block=(4,4)),dict(fine_block=(4,4))):
-            with self.assertRaisesRegex(ValueError,'all-blocked|base_block requires fine_block'):
-                module.FixedPatchStepper(cfg,(4,4,20,28),context=None,**kwargs)
+        for blocks in ([None,None],[(4,4),None],[None,(4,4)]):
+            with self.assertRaisesRegex(ValueError,'all-blocked|blocked refined levels below'):
+                module.FixedPatchStepper(cfg,context=None,refinements=[(4,4,20,28)],
+                                         level_blocks=blocks)
         module.compiler.compile_kernel.assert_not_called()
 
     def test_uniform_block_codec_and_raw_snapshot(self):

tests/unit/test_state_regressions.py

@@ -238,6 +238,81 @@ def test_overlapping_force_regions_rejected(device):
         bodies.build_compact_lists(bodies.build_flags(field.flag))
 
 
+@pytest.mark.parametrize("second_x,error", [(14., "unique cut-link writers"),
+                                           (17., "active fluid receivers")])
+def test_passive_overlap_rejected_before_publishing_lists(second_x, error):
+    cfg = LBMConfig(nx=32, ny=24)
+    cfg.validate()
+    bodies = ObjectManager(cfg.nx, cfg.ny, cfg.nz, cfg.nq, cfg)
+    for x in (14., second_x):
+        bodies.add(obj(x=x, y=12., r=4.3))
+    bodies.add(obj(x=4., y=4., r=2., is_sensor=True))
+    counts = np.full(bodies.count, 91, np.int32)
+    hits = []
+    flags = bodies.build_flags(np.full(cfg.nx * cfg.ny, FLUID, np.uint16))
+    for domain_flags in (flags, None):
+        with pytest.raises(ValueError, match=error):
+            bodies.build_compact_lists_for(bodies.objects, domain_flags,
+                                          sensor_cell_counts_out=counts, hits_out=hits)
+        np.testing.assert_array_equal(counts, 91)
+        assert hits == []
+
+
+@pytest.mark.parametrize("centers", [((10., 12.), (22., 12.)),
+                                    ((10.5, 12.), (19.5, 12.))])
+def test_separated_passive_bodies_keep_valid_writers(centers):
+    # The second case has a subcell physical gap with a resolved fluid column.
+    cfg = LBMConfig(nx=32, ny=24)
+    cfg.validate()
+    bodies = ObjectManager(cfg.nx, cfg.ny, cfg.nz, cfg.nq, cfg)
+    for x, y in centers:
+        bodies.add(obj(x=x, y=y, r=4.3))
+    flags = bodies.build_flags(np.full(cfg.nx * cfg.ny, FLUID, np.uint16))
+    indices, directions, _, ids, *_ = bodies.build_compact_lists(flags)
+    assert set(ids) == {0, 1}
+    assert np.all(flags[indices] & FLUID) and not np.any(flags[indices] & SOLID)
+    assert len(np.unique(indices.astype(np.uint64) * cfg.nq + directions)) == len(indices)
+
+
+@pytest.mark.parametrize("entry", ["sync", "initialize", "runtime_edit"])
+@pytest.mark.parametrize("second_x", [5., 6.])
+def test_passive_overlap_failure_keeps_live_state(device, entry, second_x):
+    from CelerisLab.simulation import Simulation
+    field = make_field(device)
+    bodies = manager(field, [obj(), obj(x=9., y=3., r=1., is_sensor=True)])
+    bodies.sync_to_gpu(field)
+    overlapping = obj(x=second_x)
+    if entry == "runtime_edit":
+        bodies.stage_add(overlapping)
+    else:
+        bodies.add(overlapping)
+    objects = bodies.objects
+    flags, curved, counts = field.flag.copy(), field.curved.fluid_idx.copy(), bodies.sensor_cell_counts.copy()
+    action = bodies.action.copy()
+    buffers = [(block, bytes(block.data), block.freed) for block in device.blocks]
+    writes = device.writes
+    sim = SimpleNamespace(bodies=bodies, field=field, lbm_cfg=field.cfg,
+                          _initialized=entry == "runtime_edit",
+                          _assert_allocation_contract=lambda: None,
+                          stream=SimpleNamespace(synchronize=device.synchronize))
+    with pytest.raises(ValueError, match="active fluid receivers|unique cut-link writers"):
+        if entry == "sync":
+            bodies.sync_to_gpu(field)
+        elif entry == "initialize":
+            Simulation.initialize(sim)
+        else:
+            Simulation.sync_bodies(sim)
+    assert bodies.objects == objects
+    assert bodies.has_pending_edit() == (entry == "runtime_edit")
+    assert sim._initialized == (entry == "runtime_edit")
+    assert device.writes == writes and len(device.blocks) == len(buffers)
+    assert all(bytes(block.data) == data and block.freed == freed for block, data, freed in buffers)
+    np.testing.assert_array_equal(field.flag, flags)
+    np.testing.assert_array_equal(field.curved.fluid_idx, curved)
+    np.testing.assert_array_equal(bodies.sensor_cell_counts, counts)
+    np.testing.assert_array_equal(bodies.action, action)
+
+
 def test_action_upload_and_scratch_are_pinned(device):
     field = make_field(device, streaming="esopull")
     bodies = manager(field, [obj(is_force_region=True)])

tests/unit/test_step_sync.py

@@ -0,0 +1,170 @@
+"""Host contract of FixedPatchStepper.step(n): one stream wait per call (mocked driver).
+
+All n base intervals are enqueued in order on the backend stream and the host
+waits once before step returns. Launch order and buffer arguments must equal n
+step(1) calls; completion metadata, raw-exchange and window ledgers, and failure
+invalidation are published only after that wait.
+"""
+from contextlib import nullcontext
+from unittest.mock import Mock
+import unittest
+
+import numpy as np
+
+from CelerisLab.config import LBMConfig
+from tests.unit.test_raw_exchange import body
+from tests.unit.test_refinement_three_level_multipatch import host_module
+
+BODY_LEVEL, HOPS = 3, 8  # body on L3: 2**3 hops per base interval
+
+
+def backend(window=False):
+    """Four-level host backend; every launch, memset and stream wait goes to one log."""
+    host = host_module()
+    log, allocations = [], []
+
+    def allocate(size):
+        allocations.append(Mock(size=size))
+        return allocations[-1]
+
+    module = Mock()
+    module.get_global.return_value = (Mock(), 20)
+    module.get_function.side_effect = lambda name: Mock(
+        side_effect=lambda *a, **k: log.append((name, a, k)))
+    host.compiler.load_module.return_value = module
+    host.cuda.mem_alloc.side_effect = allocate
+    host.cuda.memcpy_dtoh.side_effect = lambda array, pointer: array.fill(0)
+    host.cuda.memset_d8_async.side_effect = lambda *a: log.append(("memset", a, {}))
+    run = host.FixedPatchStepper(
+        LBMConfig(nx=48, ny=48, viscosity=.02), context=Mock(activate=nullcontext, sm_arch="sm_70"),
+        refinements=[[(6, 6, 26, 26)], [(20, 20, 44, 44)], [(56, 56, 72, 72)]],
+        level_blocks=[(4, 4)] * 4, level_objects=[(), (), (), (body(),)],
+        observe_raw_exchange=True, observe_window_exchange=window)
+    run._stream.synchronize.side_effect = lambda: log.append(("sync", (), {}))
+    run.initialize(*[np.full(level.shape, 1 / 9, np.float32) for level in run._levels])
+    log.clear()
+    return run, log, allocations
+
+
+def signature(log, allocations):
+    """Event names with device-pointer arguments replaced by allocation index."""
+    index = {id(a): i for i, a in enumerate(allocations)}
+    return [(name, tuple(index.get(id(a), "-") for a in args)) for name, args, _ in log]
+
+
+def names(log):
+    return [name for name, _, _ in log]
+
+
+class StepSync(unittest.TestCase):
+    def test_step1_waits_once_after_all_launches(self):
+        run, log, _ = backend()
+        run.step(1)
+        self.assertEqual(names(log).count("sync"), 1)
+        self.assertEqual(names(log)[-1], "sync")
+        self.assertEqual(names(log)[0], "memset")
+        self.assertEqual(names(log).count("BlockStep"), 1 + 2 + 4 + 8)
+        self.assertEqual(run.step_count, 1)
+        run.close()
+
+    def test_step_n_equals_n_step1_launches_with_one_wait(self):
+        single, single_log, single_alloc = backend()
+        for _ in range(3):
+            single.step(1)
+        batched, batched_log, batched_alloc = backend()
+        batched.step(3)
+        expected = [e for e in signature(single_log, single_alloc) if e[0] != "sync"]
+        got = signature(batched_log, batched_alloc)
+        self.assertEqual(got[-1][0], "sync")
+        self.assertEqual(names(batched_log).count("sync"), 1)
+        self.assertEqual(got[:-1], expected)  # same order, same ping-pong buffers
+        self.assertEqual(names(batched_log).count("memset"), 3)
+        self.assertEqual(batched.step_count, single.step_count)
+        index = [{id(a): i for i, a in enumerate(alloc)} for alloc in (single_alloc, batched_alloc)]
+        self.assertEqual(index[1][id(batched._levels[0].current)],
+                         index[0][id(single._levels[0].current)])
+        single.close()
+        batched.close()
+
+    def test_step0_launches_and_waits_for_nothing(self):
+        run, log, _ = backend()
+        run.step(2)
+        log.clear()
+        run.step(0)
+        self.assertEqual(log, [])
+        self.assertEqual(run.step_count, 2)
+        value = run.read_raw_exchange(0, level=BODY_LEVEL)  # step(0) keeps the ledger valid
+        self.assertEqual((value["time_start"], value["time_end"]), (1, 2))
+        run.close()
+
+    def test_completion_metadata_covers_all_intervals(self):
+        run, _, _ = backend()
+        with self.assertRaisesRegex(RuntimeError, "completed"):
+            run.read_raw_exchange(0, level=BODY_LEVEL)
+        run.step(3)
+        value = run.read_raw_exchange(0, level=BODY_LEVEL)
+        self.assertEqual((value["time_start"], value["time_end"], value["sample_count"]),
+                         (2, 3, HOPS))  # step(n) retains only the final base interval
+        run.step(2)
+        self.assertEqual(run.read_raw_exchange(0, level=BODY_LEVEL)["time_end"], 5)
+        run.close()
+
+    def test_window_accounting_across_batched_calls(self):
+        windows = []
+        for calls in ((1, 3), (4,), (1, 1, 1, 1)):
+            run, log, _ = backend(window=True)
+            run.step(1)
+            run.start_exchange_window()
+            log.clear()
+            for n in calls:
+                run.step(n)
+            self.assertEqual(names(log).count("BlockAccumulateExchange"), 2 * 4 * HOPS)
+            self.assertEqual(names(log).count("sync"), len(calls))
+            out = run.read_exchange_window(0, level=BODY_LEVEL)
+            windows.append((out["time_start"], out["time_end"], out["sample_count"]))
+            run.close()
+        self.assertEqual(windows, [(1., 5, 4 * HOPS)] * 3)
+
+    def test_failed_wait_publishes_nothing(self):
+        run, _, _ = backend(window=True)
+        run.step(2)
+        run.start_exchange_window()
+        run._stream.synchronize.side_effect = RuntimeError("device failure")
+        with self.assertRaisesRegex(RuntimeError, "device failure"):
+            run.step(3)
+        self.assertEqual(run.step_count, 2)  # value at entry to the failing call
+        self.assertFalse(run._exchange_valid)
+        self.assertFalse(run._window_valid)
+        for read in (lambda: run.read_raw_exchange(0, level=BODY_LEVEL),
+                     lambda: run.read_exchange_window(0, level=BODY_LEVEL), run.download,
+                     lambda: run.step(1)):
+            with self.assertRaisesRegex(RuntimeError, "failed"):
+                read()
+        run._stream.synchronize.side_effect = None
+        run.close()
+
+    def test_launch_error_mid_batch_skips_wait_and_fails(self):
+        run, log, _ = backend()
+        run.step(1)
+        log.clear()
+        hop, calls = run._hop, []
+
+        def failing(index, *args, **kw):
+            if index == 0:
+                calls.append(1)
+                if len(calls) == 2:
+                    raise RuntimeError("launch failure")
+            return hop(index, *args, **kw)
+        run._hop = failing
+        with self.assertRaisesRegex(RuntimeError, "launch failure"):
+            run.step(3)
+        self.assertNotIn("sync", names(log))
+        self.assertEqual(run.step_count, 1)
+        self.assertFalse(run._exchange_valid)
+        with self.assertRaisesRegex(RuntimeError, "failed"):
+            run.read_raw_exchange(0, level=BODY_LEVEL)
+        run.close()
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/validation/multigrid/test_channel_root_gpu.py

@@ -106,9 +106,10 @@ class ChannelRootGPU(unittest.TestCase):
                     cfg = LBMConfig(nx=48, ny=32, viscosity=.1, velocity=.015, ddf_shifting=shifted)
                     reference = None
                     for block in ((32,48), (8,8), (4,1)):
-                        with FixedPatchStepper(cfg, (8,6,40,26), context=context,
-                                coarse_boundary="channel", base_block=block, fine_block=(8,8),
-                                fine_objects=(body,) if bodies else (), jets=(jet,) if bodies else ()) as backend:
+                        with FixedPatchStepper(cfg, context=context, coarse_boundary="channel",
+                                refinements=[(8,6,40,26)], level_blocks=[block, (8,8)],
+                                level_objects=[(), (body,) if bodies else ()],
+                                level_jets=[(), (jet,) if bodies else ()]) as backend:
                             arrays = [state(*level.shape[1:]) for level in backend._levels]
                             backend.initialize(*arrays)
                             backend.step(4)

tests/validation/multigrid/test_exchange_window.py

@@ -25,8 +25,8 @@ EPS = np.finfo(np.float64).eps
 
 
 def build(m, window=True, raw=True):
-    return FixedPatchStepper(config("periodic"), BOUNDS, context=m["context"], base_block=(3, 4),
-                             fine_block=(16, 20), fine_objects=[circle()],
+    return FixedPatchStepper(config("periodic"), context=m["context"], refinements=[BOUNDS],
+                             level_blocks=[(3, 4), (16, 20)], level_objects=[(), (circle(),)],
                              observe_raw_exchange=raw, observe_window_exchange=window)
 
 
@@ -109,10 +109,11 @@ class ExchangeWindowGPU(unittest.TestCase):
         from test_raw_exchange_gpu import BOUNDS as RB, CFG, circle as rc, jet, state
         from CelerisLab.cuda.context import CudaContext
         with CudaContext(0) as ctx:
-            kw = dict(context=ctx, fine_block=(16, 20), fine_objects=[rc()], jets=[jet()],
+            kw = dict(context=ctx, refinements=[RB], level_blocks=[None, (16, 20)],
+                      level_objects=[(), (rc(),)], level_jets=[(), (jet(),)],
                       observe_raw_exchange=True)
-            with FixedPatchStepper(CFG, RB, observe_window_exchange=True, **kw) as windowed, \
-                 FixedPatchStepper(CFG, RB, **kw) as plain:
+            with FixedPatchStepper(CFG, observe_window_exchange=True, **kw) as windowed, \
+                 FixedPatchStepper(CFG, **kw) as plain:
                 arrays = [state(level.shape) for level in windowed._levels]
                 windowed.initialize(*arrays)
                 plain.initialize(*arrays)
@@ -200,11 +201,11 @@ class ExchangeWindowShiftedMRTGPU(unittest.TestCase):
         from CelerisLab.cuda.context import CudaContext
         cfg = LBMConfig(nx=32, ny=24, viscosity=.1, collision="MRT", ddf_shifting=True)
         with CudaContext(0) as ctx:
-            kw = dict(context=ctx, base_block=(12, 8), fine_block=(16, 20), fine_objects=[rc()],
-                      observe_raw_exchange=True)
-            with FixedPatchStepper(cfg, RB, observe_window_exchange=True, **kw) as windowed, \
-                 FixedPatchStepper(cfg, RB, observe_window_exchange=True, **kw) as split, \
-                 FixedPatchStepper(cfg, RB, **kw) as plain:
+            kw = dict(context=ctx, refinements=[RB], level_blocks=[(12, 8), (16, 20)],
+                      level_objects=[(), (rc(),)], observe_raw_exchange=True)
+            with FixedPatchStepper(cfg, observe_window_exchange=True, **kw) as windowed, \
+                 FixedPatchStepper(cfg, observe_window_exchange=True, **kw) as split, \
+                 FixedPatchStepper(cfg, **kw) as plain:
                 arrays = [state(level.shape) for level in windowed._levels]
                 for run in (windowed, split, plain):
                     run.initialize(*arrays)

tests/validation/multigrid/test_fine_surface_gpu.py

@@ -140,7 +140,8 @@ def run_patch(speed, *, audit=True):
         build = (patch.object(compiler, "compile_kernel", audit_compiler(compiler.compile_kernel))
                  if audit else nullcontext())
         with build:
-            backend = implementation.FixedPatchStepper(cfg, BOUNDS, context=context, fine_objects=[source])
+            backend = implementation.FixedPatchStepper(cfg, context=context, refinements=[BOUNDS],
+                                             level_objects=[(), (source,)])
         with backend, context.activate():
             c, f = backend._levels
             cl = backend._fine_curved
@@ -325,6 +326,7 @@ def test_cross_interface_donor_rejects_before_cuda():
     context.activate.side_effect = AssertionError("must reject before CUDA activation")
     with patch.object(cuda, "mem_alloc") as allocate:
         with pytest.raises(ValueError, match="donor crosses"):
-            implementation.FixedPatchStepper(cfg, BOUNDS, context=context, fine_objects=[source])
+            implementation.FixedPatchStepper(cfg, context=context, refinements=[BOUNDS],
+                                             level_objects=[(), (source,)])
         context.activate.assert_not_called()
         allocate.assert_not_called()

tests/validation/multigrid/test_multiple_pinned_remap_gpu.py

@@ -48,9 +48,8 @@ def make(context):
         for (x, y), amplitude in zip(centers, (.003, -.002))
     )
     run = FixedPatchStepper(
-        CFG, PARENTS, context=context, base_block=(4, 4), fine_block=(4, 4),
-        child_block=(4, 4), child_rectangles_in_parent=START,
-        child_objects=objects, child_jets=jets,
+        CFG, context=context, refinements=[PARENTS, START], level_blocks=[(4, 4)] * 3,
+        level_objects=[(), (), objects], level_jets=[(), (), jets],
     )
     return run, objects
 

tests/validation/multigrid/test_pinned_body_remap_gpu.py

@@ -25,9 +25,8 @@ B = ((16,16,32,40), (60,16,76,40))
 def make(ctx):
     body = SimObject(71, geometry=CircleGeometry(12.,14.,.8),center=(12.,14.),radius=.8)
     jet = Jet(Tube((10.5,14.),0.,3.,.3),Parallel(0.),'parabolic',.003)
-    run = FixedPatchStepper(CFG,PARENTS,context=ctx,base_block=(4,4),fine_block=(4,4),
-                           child_block=(4,4),child_rectangles_in_parent=A,
-                           child_objects=(body,),child_jets=(jet,))
+    run = FixedPatchStepper(CFG,context=ctx,refinements=[PARENTS,A],level_blocks=[(4,4)]*3,
+                           level_objects=[(),(),(body,)],level_jets=[(),(),(jet,)])
     return run,(body,)
 
 

tests/validation/multigrid/test_raw_exchange_gpu.py

@@ -90,14 +90,18 @@ def census(run, index, buffer):
     return totals(dense, leaf), external, independent
 
 
+
+def fine(block):
+    """Two-level circle+jet construction on BOUNDS; block None keeps the dense fine level."""
+    return dict(refinements=[BOUNDS], level_blocks=[None, block],
+                level_objects=[(), (circle(),)], level_jets=[(), (jet(),)])
+
 class RawExchangeGPU(unittest.TestCase):
     def test_row_ledger_interval_jet_switch_and_no_population_effect(self):
         with CudaContext(0) as ctx:
             for block in ((32, 40), (16, 20), (8, 10)):
-                with FixedPatchStepper(CFG, BOUNDS, context=ctx, fine_block=block,
-                        fine_objects=[circle()], jets=[jet()], observe_raw_exchange=True) as measured, \
-                     FixedPatchStepper(CFG, BOUNDS, context=ctx, fine_block=block,
-                        fine_objects=[circle()], jets=[jet()]) as plain:
+                with FixedPatchStepper(CFG, context=ctx, **fine(block), observe_raw_exchange=True) as measured, \
+                     FixedPatchStepper(CFG, context=ctx, **fine(block)) as plain:
                     arrays = [state(l.shape) for l in measured._levels]
                     measured.initialize(*arrays)
                     plain.initialize(*arrays)
@@ -146,9 +150,8 @@ class RawExchangeGPU(unittest.TestCase):
         """Same fine resolution/initial data with dense storage: a numerical
         reference for cut-link rows, not a uniform-whole-domain convergence study."""
         with CudaContext(0) as ctx:
-            with FixedPatchStepper(CFG, BOUNDS, context=ctx, fine_objects=[circle()], jets=[jet()]) as dense, \
-                 FixedPatchStepper(CFG, BOUNDS, context=ctx, fine_block=(16, 20),
-                    fine_objects=[circle()], jets=[jet()], observe_raw_exchange=True) as blocked:
+            with FixedPatchStepper(CFG, context=ctx, **fine(None)) as dense, \
+                 FixedPatchStepper(CFG, context=ctx, **fine((16, 20)), observe_raw_exchange=True) as blocked:
                 arrays = [state(l.shape) for l in blocked._levels]
                 dense.initialize(*arrays)
                 blocked.initialize(*arrays)
@@ -229,8 +232,7 @@ class RawExchangeGPU(unittest.TestCase):
         layout = BlockLayout2D.build(48, 64, 8, 8)
         with CudaContext(0) as ctx:
             with PeriodicBlockStepper(fine_cfg, layout, context=ctx, objects=[obj]) as uniform, \
-                 FixedPatchStepper(CFG, BOUNDS, context=ctx, fine_block=(16, 20),
-                    fine_objects=[circle()], jets=[jet()], observe_raw_exchange=True) as amr:
+                 FixedPatchStepper(CFG, context=ctx, **fine((16, 20)), observe_raw_exchange=True) as amr:
                 amr.initialize(*(state(l.shape) for l in amr._levels))
                 uniform.initialize(state((9, 48, 64)))
                 b = amr._level_boundaries[1]

tests/validation/multigrid/test_refinement_blocked_base.py

@@ -83,11 +83,10 @@ def mocked_backend(mode="periodic", fail_alloc=None):
 class BlockedBaseCPU(unittest.TestCase):
     def test_reject_before_cuda(self):
         context = Mock(activate=Mock(side_effect=AssertionError("CUDA reached")))
-        for kwargs in ({"base_block": (12, 8)},
-                       {"base_block": (7, 8), "fine_block": FINE_BLOCK},
-                       {"base_block": (12,), "fine_block": FINE_BLOCK}):
-            with self.subTest(kwargs=kwargs), self.assertRaises(ValueError):
-                FixedPatchStepper(config("periodic"), BOUNDS, context=context, **kwargs)
+        for blocks in ([(12, 8), None], [(7, 8), FINE_BLOCK], [(12,), FINE_BLOCK]):
+            with self.subTest(blocks=blocks), self.assertRaises(ValueError):
+                FixedPatchStepper(config("periodic"), context=context, refinements=[BOUNDS],
+                                  level_blocks=blocks)
         context.activate.assert_not_called()
 
     def test_all_arrival_rows_donors_and_kind_masks(self):
@@ -193,9 +192,10 @@ class BlockedBaseCPU(unittest.TestCase):
 
     def test_launch_order_stream_wall_constants_and_buffer_swaps(self):
         with mocked_backend("slot_reservoir") as m:
-            backend = FixedPatchStepper(config("slot_reservoir"), BOUNDS, context=m["context"],
-                                        coarse_boundary="slot_reservoir", fine_block=FINE_BLOCK,
-                                        base_block=(3, 4), fine_objects=[circle(actuation(.002))])
+            backend = FixedPatchStepper(config("slot_reservoir"), context=m["context"],
+                                        coarse_boundary="slot_reservoir", refinements=[BOUNDS],
+                                        level_blocks=[(3, 4), FINE_BLOCK],
+                                        level_objects=[(), (circle(actuation(.002)),)])
             try:
                 backend.initialize(state(NY, NX, 1), state(*backend.patch.fine_shape, 2))
                 coarse, fine = backend._levels
@@ -236,16 +236,16 @@ class BlockedBaseCPU(unittest.TestCase):
         for fail_at in (1, 6, 10):
             with self.subTest(fail_at=fail_at), mocked_backend(fail_alloc=fail_at) as m:
                 with self.assertRaisesRegex(MemoryError, "injected allocation"):
-                    FixedPatchStepper(config("periodic"), BOUNDS, context=m["context"],
-                                      fine_block=FINE_BLOCK, base_block=(3, 4))
+                    FixedPatchStepper(config("periodic"), context=m["context"], refinements=[BOUNDS],
+                                      level_blocks=[(3, 4), FINE_BLOCK])
                 self.assertEqual(len(m["allocations"]), fail_at)
                 for allocation in m["allocations"]:
                     allocation.free.assert_called_once_with()
 
     def test_failed_parent_stage_cannot_publish_or_resume(self):
         with mocked_backend() as m:
-            backend = FixedPatchStepper(config("periodic"), BOUNDS, context=m["context"],
-                                        fine_block=FINE_BLOCK, base_block=(3, 4))
+            backend = FixedPatchStepper(config("periodic"), context=m["context"], refinements=[BOUNDS],
+                                        level_blocks=[(3, 4), FINE_BLOCK])
             backend.initialize(state(NY, NX, 1), state(*backend.patch.fine_shape, 2))
             m["functions"]["BlockCoalesce"].side_effect = RuntimeError("injected parent stage failure")
             current = backend._levels[0].current
@@ -289,9 +289,10 @@ class BlockedBaseGPU(unittest.TestCase):
                     for base_block in (None, *layouts):
                         label = f"{mode} width={width} speed={speed} base={base_block}"
                         snapshots = []
-                        with FixedPatchStepper(cfg, BOUNDS, context=context, coarse_boundary=mode,
-                                               fine_block=FINE_BLOCK, base_block=base_block,
-                                               fine_objects=() if speed is None else [circle(actuation(speed))]) as backend:
+                        with FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                               refinements=[BOUNDS], level_blocks=[base_block, FINE_BLOCK],
+                                               level_objects=[(), () if speed is None
+                                                              else (circle(actuation(speed)),)]) as backend:
                             backend.initialize(*arrays)
                             for step in (0, 1, 2, 8):
                                 if step == 1 and base_block is not None:

tests/validation/multigrid/test_refinement_blocked_fine.py

@@ -105,9 +105,10 @@ class BlockedFineCPU(unittest.TestCase):
         return Mock(activate=Mock(side_effect=AssertionError("CUDA reached")), sm_arch="sm_70")
 
     def test_rejections_before_cuda(self):
-        for kw in ({"fine_block": (7, 7)}, {"fine_block": (16,)}):
+        for kw in ({"level_blocks": [None, (7, 7)]}, {"level_blocks": [None, (16,)]}):
             with self.subTest(kw=kw), self.assertRaises(ValueError):
-                FixedPatchStepper(config("periodic"), BOUNDS, context=self.forbidden_context(), **kw)
+                FixedPatchStepper(config("periodic"), context=self.forbidden_context(),
+                                  refinements=[BOUNDS], **kw)
 
     def test_single_block_layout_allocates_no_empty_halo_tables(self):
         # A 1x1 non-periodic fine layout has zero halo pairs; CUDA rejects mem_alloc(0).
@@ -125,8 +126,8 @@ class BlockedFineCPU(unittest.TestCase):
                 patch.object(compiler, "compile_kernel"), patch.object(compiler, "cleanup_build_dir"), \
                 patch.object(compiler, "load_module", return_value=module), \
                 patch.object(cuda, "mem_alloc", side_effect=alloc), patch.object(cuda, "memcpy_htod"):
-            backend = FixedPatchStepper(config("periodic"), BOUNDS, context=context,
-                                        fine_block=FINE_BLOCKS[0])
+            backend = FixedPatchStepper(config("periodic"), context=context, refinements=[BOUNDS],
+                                        level_blocks=[None, FINE_BLOCKS[0]])
             self.assertEqual(len(backend.fine_layout.halo_dst), 0)
             self.assertIsNone(backend._levels[1].halo_dst)
             backend._gather_halo(backend._levels[1], Mock())  # no launch without pairs
@@ -177,8 +178,9 @@ class BlockedFineCPU(unittest.TestCase):
                 patch.object(cuda, "mem_alloc", side_effect=lambda size: Mock()), \
                 patch.object(cuda, "memcpy_htod"), \
                 patch.object(curved_links, "CurvedLinkSoA", side_effect=AssertionError("dense SoA built")):
-            backend = FixedPatchStepper(config("periodic"), BOUNDS, context=context,
-                                        fine_objects=objects, fine_block=FINE_BLOCKS[1])
+            backend = FixedPatchStepper(config("periodic"), context=context, refinements=[BOUNDS],
+                                        level_blocks=[None, FINE_BLOCKS[1]],
+                                        level_objects=[(), tuple(objects)])
             backend.initialize(state(NY, NX, 1), state(*backend.patch.fine_shape, 2))
         return backend, calls
 
@@ -289,8 +291,9 @@ class BlockedFineGPU(unittest.TestCase):
             results = []
             with CudaContext(0) as context:
                 for fine_block in (None, *FINE_BLOCKS):
-                    with FixedPatchStepper(cfg, BOUNDS, context=context, coarse_boundary=mode,
-                                           fine_block=fine_block) as backend:
+                    with FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                           refinements=[BOUNDS],
+                                           level_blocks=[None, fine_block]) as backend:
                         backend.initialize(g_coarse, g_fine)
                         backend.step(STEPS)
                         self.assertEqual(backend.step_count, STEPS)
@@ -318,8 +321,9 @@ class BlockedFineGPU(unittest.TestCase):
             results = []
             with CudaContext(0) as context:
                 for fine_block in (None, *FINE_BLOCKS):
-                    with FixedPatchStepper(cfg, BOUNDS, context=context, coarse_boundary=mode,
-                                           fine_objects=[circle()], fine_block=fine_block) as backend:
+                    with FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                           refinements=[BOUNDS], level_blocks=[None, fine_block],
+                                           level_objects=[(), (circle(),)]) as backend:
                         backend.initialize(g_coarse, g_fine)
                         backend.step(STEPS)
                         results.append((backend.download(), raw(backend)))
@@ -346,9 +350,9 @@ class BlockedFineGPU(unittest.TestCase):
                 results = []
                 with CudaContext(0) as context:
                     for fine_block in (None, *FINE_BLOCKS):
-                        with FixedPatchStepper(cfg, BOUNDS, context=context, coarse_boundary=mode,
-                                               fine_objects=[circle(actuation(speed))],
-                                               fine_block=fine_block) as backend:
+                        with FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                               refinements=[BOUNDS], level_blocks=[None, fine_block],
+                                               level_objects=[(), (circle(actuation(speed)),)]) as backend:
                             backend.initialize(g_coarse, g_fine)
                             backend.step(STEPS)
                             results.append((backend.download(), raw(backend)))

tests/validation/multigrid/test_refinement_followup.py

@@ -94,7 +94,8 @@ class FaultGuardsCPU(unittest.TestCase):
                              ("slot_reservoir", (12, 4, 20, 21))):
             with self.subTest(mode=mode, bounds=bounds):
                 with self.assertRaises(ValueError):
-                    implementation.FixedPatchStepper(cfg, bounds, context=context, coarse_boundary=mode)
+                    implementation.FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                                     refinements=[bounds])
                 context.activate.assert_not_called()
         # Both exact channel limits and the original periodic two-cell margin
         # must reach context activation, with no allocation or device required.
@@ -102,7 +103,8 @@ class FaultGuardsCPU(unittest.TestCase):
                              ("periodic", (2, 2, 6, 5))):
             with self.subTest(mode=mode, bounds=bounds):
                 with self.assertRaisesRegex(RuntimeError, "validated before CUDA"):
-                    implementation.FixedPatchStepper(cfg, bounds, context=context, coarse_boundary=mode)
+                    implementation.FixedPatchStepper(cfg, context=context, coarse_boundary=mode,
+                                                     refinements=[bounds])
 
     def fake_backend(self):
         backend = PeriodicPatchStepper.__new__(PeriodicPatchStepper)
@@ -154,12 +156,12 @@ class FaultGuardsCPU(unittest.TestCase):
         context = Mock(activate=nullcontext, sm_arch="sm_70")
         with patch.object(implementation, "HALO", 2):
             with self.assertRaisesRegex(RuntimeError, "four-cell"):
-                PeriodicPatchStepper(cfg, (4, 4, 12, 12), context=context)
+                PeriodicPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)])
         p = implementation.FixedPatch2D.from_config(cfg, (4, 4, 12, 12))
         with patch.object(cuda, "Stream"), patch.object(implementation.FixedPatch2D, "from_config",
                                                        return_value=replace(p, tau_coarse=.9)):
             with self.assertRaisesRegex(RuntimeError, "omega/tau"):
-                PeriodicPatchStepper(cfg, p.bounds, context=context)
+                PeriodicPatchStepper(cfg, context=context, refinements=[p.bounds])
         module = Mock()
         module.get_global.return_value = (Mock(), 16)
         with patch.object(cuda, "Stream"), patch.object(compiler, "generate_config"), \
@@ -167,7 +169,7 @@ class FaultGuardsCPU(unittest.TestCase):
                 patch.object(compiler, "load_module", return_value=module), \
                 patch.object(cuda, "memcpy_htod") as upload:
             with self.assertRaisesRegex(RuntimeError, "layout mismatch"):
-                PeriodicPatchStepper(cfg, p.bounds, context=context)
+                PeriodicPatchStepper(cfg, context=context, refinements=[p.bounds])
             upload.assert_not_called()
 
 
@@ -241,7 +243,7 @@ class NormalBuildGPU(unittest.TestCase):
         max_error = max_bc_error = 0.0
         with CudaContext(0) as context:
             with patch.object(compiler, "generate_config", side_effect=record_config):
-                backend = implementation.FixedPatchStepper(cfg, bounds, context=context,
+                backend = implementation.FixedPatchStepper(cfg, context=context, refinements=[bounds],
                                                             coarse_boundary="slot_reservoir")
             with backend:
                 self.assertEqual(len(generated), 2)
@@ -311,7 +313,8 @@ class NormalBuildGPU(unittest.TestCase):
                             for a in (initial.coarse_f, initial.fine_f)))
         max_pop = max_drift = max_moment = 0.0
         with CudaContext(0) as context, PeriodicPatchStepper(
-                LBMConfig(nx=16, ny=16, viscosity=.1), (4, 4, 12, 12), context=context) as backend:
+                LBMConfig(nx=16, ny=16, viscosity=.1), context=context,
+                refinements=[(4, 4, 12, 12)]) as backend:
             backend.initialize(*postcollision(state, spec, maps))
             before = totals(backend.download(), maps)
             for step in range(1, 9):
@@ -342,7 +345,7 @@ class NormalBuildGPU(unittest.TestCase):
         fine_mask[4:-4, 4:-4] = True
         initial[1][:, ~fine_mask] = np.nan
         expected = scalar_interval(*[a.astype(np.float64) for a in initial], bounds)
-        with CudaContext(0) as context, PeriodicPatchStepper(cfg, bounds, context=context) as backend:
+        with CudaContext(0) as context, PeriodicPatchStepper(cfg, context=context, refinements=[bounds]) as backend:
             self.assertEqual(backend.patch.fine_shape, (14, 16))
             p = backend.patch
             allocated = 2 * 9 * (17*13+16*14) * 4 + sum(a.nbytes for a in

tests/validation/multigrid/test_refinement_gpu.py

@@ -84,13 +84,13 @@ class CoupledGPU(unittest.TestCase):
 
         cases = (("dense_unshifted", False, {}),
                  ("blocked_shifted", True,
-                  dict(base_block=(4, 4), fine_block=(6, 6))))
+                  dict(level_blocks=[(4, 4), (6, 6)])))
         with CudaContext(0) as context:
             for label, shifted, storage in cases:
                 with self.subTest(storage=label):
                     cfg = LBMConfig(nx=16, ny=16, viscosity=.0192,
                                     ddf_shifting=shifted)
-                    with FixedPatchStepper(cfg, (4, 4, 12, 12), context=context,
+                    with FixedPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)],
                                            **storage) as backend:
                         self.assertAlmostEqual(backend.patch.tau_coarse, spec.tau_coarse)
                         self.assertAlmostEqual(backend.patch.tau_fine, spec.tau_fine)
@@ -148,7 +148,7 @@ class CoupledGPU(unittest.TestCase):
         maps = ref.build_maps(spec)
         with CudaContext(0) as context:
             with PeriodicPatchStepper(LBMConfig(nx=16, ny=16, viscosity=.1),
-                                      (4, 4, 12, 12), context=context) as backend:
+                                      context=context, refinements=[(4, 4, 12, 12)]) as backend:
                 backend.initialize(*postcollision(ref.make_state(spec), spec, maps))
                 coarse, fine = backend._levels
 
@@ -187,7 +187,7 @@ class CoupledGPU(unittest.TestCase):
 
         with CudaContext(0) as context:
             with patch.object(compiler, "compile_kernel", audit_compile):
-                backend = PeriodicPatchStepper(cfg, (4, 4, 12, 12), context=context)
+                backend = PeriodicPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)])
             with backend:
                 # Production allocations: four DDF arrays and four compact tables.
                 device_bytes = 2 * 9 * (16**2 + 24**2) * 4
@@ -270,7 +270,7 @@ class CoupledGPU(unittest.TestCase):
                 backend.download()
 
             # Compile and execute the actual non-audited entry as well: one step.
-            with PeriodicPatchStepper(cfg, (4, 4, 12, 12), context=context) as plain:
+            with PeriodicPatchStepper(cfg, context=context, refinements=[(4, 4, 12, 12)]) as plain:
                 rest = postcollision(ref.make_state(spec), spec, maps)
                 plain.initialize(*rest)
                 plain.step()

tests/validation/multigrid/test_refinement_jets.py

@@ -41,8 +41,9 @@ def mocked(objects, jets, fine_block):
             patch.object(compiler, "load_module", return_value=module), \
             patch.object(cuda, "mem_alloc", side_effect=lambda size: Mock()), \
             patch.object(cuda, "memcpy_htod", htod):
-        backend = FixedPatchStepper(config("periodic"), BOUNDS, context=context,
-                                    fine_objects=objects, fine_block=fine_block, jets=jets)
+        backend = FixedPatchStepper(config("periodic"), context=context, refinements=[BOUNDS],
+                                    level_blocks=[None, fine_block], level_objects=[(), tuple(objects)],
+                                    level_jets=[(), tuple(jets)])
     return backend, htod
 
 
@@ -149,8 +150,9 @@ class JetStepperCPU(unittest.TestCase):
     def test_jet_overlapping_legacy_aperture_rejected_before_cuda(self):
         with patch.object(cuda, "Stream", side_effect=AssertionError("CUDA touched")):
             with self.assertRaisesRegex(ValueError, "SurfaceActuation"):
-                FixedPatchStepper(config("periodic"), BOUNDS, context=Mock(),
-                                  fine_objects=[circle(actuation(SPEED))], jets=[jet()])
+                FixedPatchStepper(config("periodic"), context=Mock(), refinements=[BOUNDS],
+                                  level_objects=[(), (circle(actuation(SPEED)),)],
+                                  level_jets=[(), (jet(),)])
 
 
 def run(mode, fine_block, *, objects, jets, switch=None):
@@ -158,8 +160,9 @@ def run(mode, fine_block, *, objects, jets, switch=None):
     cfg = config(mode)
     patch_ = FixedPatch2D.from_config(cfg, BOUNDS)
     with CudaContext(0) as context, FixedPatchStepper(
-            cfg, BOUNDS, context=context, coarse_boundary=mode, fine_objects=objects,
-            fine_block=fine_block, jets=jets) as backend:
+            cfg, context=context, coarse_boundary=mode, refinements=[BOUNDS],
+            level_blocks=[None, fine_block], level_objects=[(), tuple(objects)],
+            level_jets=[(), tuple(jets)]) as backend:
         backend.initialize(state(NY, NX, 1), state(*patch_.fine_shape, 2))
         if switch is None:
             backend.step(STEPS)

tests/validation/multigrid/test_refinement_mrt_gpu.py

@@ -42,8 +42,9 @@ class RefinementMRTGPU(unittest.TestCase):
                                     collision="MRT", ddf_shifting=shifted)
                     reference = None
                     for block in ((32, 48), (8, 8), (4, 1)):
-                        with FixedPatchStepper(cfg, (8, 6, 40, 26), context=context, coarse_boundary=boundary,
-                                               base_block=block, fine_block=(8, 8), fine_objects=(body,)) as backend:
+                        with FixedPatchStepper(cfg, context=context, coarse_boundary=boundary,
+                                               refinements=[(8, 6, 40, 26)], level_blocks=[block, (8, 8)],
+                                               level_objects=[(), (body,)]) as backend:
                             backend.initialize(*[state(*level.shape[1:]) for level in backend._levels])
                             backend.step(8)
                             raw = backend._download_raw()
@@ -63,8 +64,8 @@ class RefinementMRTGPU(unittest.TestCase):
             results = {}
             layouts = ((None, None), *((base, FINE_BLOCK) for base in (None, *BASE_BLOCKS)))
             for base_block, fine_block in layouts:
-                with FixedPatchStepper(cfg, BOUNDS, context=context, fine_block=fine_block,
-                                       base_block=base_block) as backend:
+                with FixedPatchStepper(cfg, context=context, refinements=[BOUNDS],
+                                       level_blocks=[base_block, fine_block]) as backend:
                     backend.initialize(*[fixture.state(*level.shape[1:], seed) for seed, level in enumerate(backend._levels)])
                     backend.step(4)
                     results[base_block, fine_block] = raw(backend)
@@ -75,9 +76,9 @@ class RefinementMRTGPU(unittest.TestCase):
     def test_shifted_all_blocked_three_level_mrt_smoke(self):
         """Per-level shear rate omega_l = 1/(3*2**l*nu + 1/2); finite ACTIVE leaves."""
         cfg = LBMConfig(nx=16, ny=16, viscosity=.1, collision="MRT", ddf_shifting=True)
-        kw = dict(fine_block=(4, 4), base_block=(4, 4), child=(8, 8, 16, 16), child_block=(4, 4))
+        kw = dict(refinements=[(4, 4, 12, 12), (8, 8, 16, 16)], level_blocks=[(4, 4)] * 3)
         with CudaContext(0) as context:
-            with FixedPatchStepper(cfg, (4, 4, 12, 12), context=context, **kw) as backend:
+            with FixedPatchStepper(cfg, context=context, **kw) as backend:
                 self.assertEqual(len(backend._level_cfgs), 3)
                 for level, level_cfg in enumerate(backend._level_cfgs):
                     checked = replace(level_cfg)

tests/validation/multigrid/test_refinement_multipatch.py

@@ -26,6 +26,12 @@ FACE = ((4, 4, 8, 12), (12, 4, 16, 12))
 S1 = ((4, 4, 12, 12), (20, 4, 28, 12))
 
 
+def levels(bounds, blocks=(None, None), objects=(), jets=(), **rest):
+    """Two-level constructor keywords: one L1 rectangle or set, per-level blocks, L1 bodies/Jets."""
+    return dict(refinements=[bounds], level_blocks=list(blocks),
+                level_objects=[(), tuple(objects)], level_jets=[(), tuple(jets)], **rest)
+
+
 def level_fine(patch_set, windows):
     """Level-wide fine array with each patch window filled from `windows`."""
     out = np.full((9, *patch_set.fine_shape), np.nan, np.float32)
@@ -45,21 +51,21 @@ class MultipatchCPU(unittest.TestCase):
     def test_rejections_before_cuda(self):
         cfg = config("periodic")
         context = object()  # never activated: every case must fail first
-        for kw in (dict(), dict(fine_block=(8, 4)), dict(base_block=(4, 4)),
-                   dict(fine_block=(8, 4), base_block=(4, 4), fine_objects=[circle()]),
-                   dict(fine_block=(5, 4), base_block=(4, 4))):
+        for kw in (dict(), dict(blocks=(None, (8, 4))), dict(blocks=((4, 4), None)),
+                   dict(blocks=((4, 4), (8, 4)), objects=[circle()]),
+                   dict(blocks=((4, 4), (5, 4)))):
             with self.subTest(kw=kw), self.assertRaises(ValueError):
-                FixedPatchStepper(cfg, ((4, 4, 8, 12), (14, 4, 18, 12)), context=context, **kw)
+                FixedPatchStepper(cfg, context=context, **levels(((4, 4, 8, 12), (14, 4, 18, 12)), **kw))
         with self.assertRaisesRegex(ValueError, "margin"):
-            FixedPatchStepper(cfg, ((1, 4, 8, 12), (10, 4, 14, 12)), context=context,
-                              fine_block=(8, 4), base_block=(4, 4))
+            FixedPatchStepper(cfg, context=context,
+                              **levels(((1, 4, 8, 12), (10, 4, 14, 12)), blocks=((4, 4), (8, 4))))
         from CelerisLab.body.jets import Jet, Parallel, Tube
         cfg32 = LBMConfig(nx=32, ny=16, viscosity=.1)
         span = Jet(Tube((5., 8.), 0., 22., .6), Parallel(0.), amplitude=0.)
         with self.assertRaisesRegex(ValueError, "one jet"):  # same obj_id cannot bypass it
-            FixedPatchStepper(cfg32, ((2, 2, 14, 14), (18, 2, 30, 14)), context=context,
-                              fine_block=(4, 4), base_block=(4, 4),
-                              fine_objects=[body(8., 8.), body(24., 8.)], jets=[span])
+            FixedPatchStepper(cfg32, context=context,
+                              **levels(((2, 2, 14, 14), (18, 2, 30, 14)), blocks=((4, 4), (4, 4)),
+                                       objects=[body(8., 8.), body(24., 8.)], jets=[span]))
 
 
 class MultipatchGPU(unittest.TestCase):
@@ -67,7 +73,7 @@ class MultipatchGPU(unittest.TestCase):
 
     def run_steps(self, context, cfg, bounds, coarse, fine, **kw):
         out = []
-        with FixedPatchStepper(cfg, bounds, context=context, **kw) as backend:
+        with FixedPatchStepper(cfg, context=context, **levels(bounds, **kw)) as backend:
             backend.initialize(coarse, fine)
             for step in self.STEPS:
                 backend.step(step - backend.step_count)
@@ -82,7 +88,7 @@ class MultipatchGPU(unittest.TestCase):
                 p = FixedPatch2D.from_config(cfg, BOUNDS)
                 s = FixedPatchSet2D.from_config(cfg, (BOUNDS,))
                 coarse, fine = state(NY, NX, 1), state(*p.fine_shape, 2)
-                kw = dict(coarse_boundary=mode, fine_block=(8, 4), base_block=(3, 4))
+                kw = dict(coarse_boundary=mode, blocks=((3, 4), (8, 4)))
                 old = self.run_steps(context, cfg, BOUNDS, coarse, fine, **kw)
                 new = self.run_steps(context, cfg, (BOUNDS,), coarse, level_fine(s, [fine]), **kw)
                 for step, a, b in zip(self.STEPS, old, new):
@@ -99,7 +105,7 @@ class MultipatchGPU(unittest.TestCase):
         one = FixedPatchSet2D.from_config(cfg16, (S1[0],))
         two = FixedPatchSet2D.from_config(cfg32, S1)
         coarse, fine = state(16, 16, 3), state(*one.patches[0].fine_shape, 4)
-        kw = dict(fine_block=(4, 4), base_block=(4, 4))
+        kw = dict(blocks=((4, 4), (4, 4)))
         with CudaContext(0) as context:
             ref = self.run_steps(context, cfg16, (S1[0],), coarse, level_fine(one, [fine]), **kw)
             tiled = np.concatenate([coarse, coarse], axis=2)
@@ -118,7 +124,7 @@ class MultipatchGPU(unittest.TestCase):
         s = FixedPatchSet2D.from_config(cfg, FACE)
         coarse = state(16, 24, 5)
         fine = level_fine(s, [state(*p.fine_shape, 6 + i) for i, p in enumerate(s.patches)])
-        kw = dict(fine_block=(4, 4), base_block=(4, 4))
+        kw = dict(blocks=((4, 4), (4, 4)))
         leaf = s.fine_kind == ACTIVE
         support = s.fine_layout((4, 4)).owned
         outer = support & (s.fine_kind == OUTER_GHOST)
@@ -164,7 +170,7 @@ class MultipatchBodiesGPU(unittest.TestCase):
 
     def run_steps(self, context, cfg, bounds, coarse, fine, switch=None, **kw):
         out = []
-        with FixedPatchStepper(cfg, bounds, context=context, **kw) as backend:
+        with FixedPatchStepper(cfg, context=context, **levels(bounds, **kw)) as backend:
             backend.initialize(coarse, fine)
             for step in self.STEPS:
                 if switch is not None and step == 8:
@@ -182,8 +188,7 @@ class MultipatchBodiesGPU(unittest.TestCase):
                 p = FixedPatch2D.from_config(cfg, BOUNDS)
                 s = FixedPatchSet2D.from_config(cfg, (BOUNDS,))
                 coarse, fine = state(NY, NX, 1), state(*p.fine_shape, 2)
-                kw = dict(coarse_boundary=mode, fine_block=(8, 4), base_block=(3, 4),
-                          fine_objects=[circle()])
+                kw = dict(coarse_boundary=mode, blocks=((3, 4), (8, 4)), objects=[circle()])
                 old = self.run_steps(context, cfg, BOUNDS, coarse, fine, **kw)
                 new = self.run_steps(context, cfg, (BOUNDS,), coarse, level_fine(s, [fine]), **kw)
                 for step, a, b in zip(self.STEPS, old, new):
@@ -202,17 +207,17 @@ class MultipatchBodiesGPU(unittest.TestCase):
         two = FixedPatchSet2D.from_config(cfg32, self.PATCHES)
         coarse, fine = state(16, 16, 3), state(*one.patches[0].fine_shape, 4)
         jet = lambda x: Jet(Tube((x, 8.), 0., 6., .6), Parallel(0.), amplitude=.002)
-        kw = dict(fine_block=(4, 4), base_block=(4, 4))
+        kw = dict(blocks=((4, 4), (4, 4)))
         with CudaContext(0) as context:
             for jets in ((), (jet(5.),)):
                 ref = self.run_steps(context, cfg16, self.PATCHES[:1], coarse, level_fine(one, [fine]),
                                      switch=[(0, -.001)] if jets else None,
-                                     fine_objects=[body(8., 8.)], jets=jets, **kw)
+                                     objects=[body(8., 8.)], jets=jets, **kw)
                 both = jets and (jet(5.), jet(21.))
                 got = self.run_steps(context, cfg32, self.PATCHES, np.concatenate([coarse, coarse], 2),
                                      level_fine(two, [fine, fine]),
                                      switch=[(0, -.001), (1, -.001)] if jets else None,
-                                     fine_objects=[body(8., 8., 5), body(24., 8., 5)],
+                                     objects=[body(8., 8., 5), body(24., 8., 5)],
                                      jets=both or (), **kw)
                 for step, a, b in zip(self.STEPS, ref, got):
                     label = f"jets={len(jets)} step {step}"

tests/validation/multigrid/test_refinement_three_level.py

@@ -27,7 +27,16 @@ from test_refinement_blocked_base import raw
 
 CFG = LBMConfig(nx=16, ny=16, viscosity=.1)
 L1, L2 = (4, 4, 12, 12), (8, 8, 16, 16)
-KW = dict(fine_block=(4, 4), base_block=(4, 4), child=L2, child_block=(4, 4))
+B = (4, 4)
+
+
+def levels(l1=L1, l2=L2, blocks=(B, B, B), objects=((), (), ()), jets=((), (), ())):
+    """Level-list keywords for the scalar L1 patch with one scalar L2 child."""
+    return dict(refinements=[l1, l2], level_blocks=list(blocks),
+                level_objects=list(objects), level_jets=list(jets))
+
+
+KW = levels()
 
 
 def child_body(spec=None):
@@ -52,26 +61,29 @@ def mocked_child():
             patch.object(compiler, "load_module", return_value=module), \
             patch.object(cuda, "mem_alloc", side_effect=lambda size: Mock()), \
             patch.object(cuda, "memcpy_htod"):
-        return FixedPatchStepper(CFG, L1, context=context, child_objects=[child_body()],
-                                 child_jets=[child_jet()], **KW)
+        return FixedPatchStepper(CFG, context=context,
+                                 **levels(objects=((), (), (child_body(),)), jets=((), (), (child_jet(),))))
 
 
 class ThreeLevelCPU(unittest.TestCase):
     def test_rejections_before_cuda(self):
         context = object()  # never activated: every case must fail first
-        bad = (dict(KW, child_block=None), dict(KW, fine_block=None),
-               dict(KW, fine_objects=[circle()]), dict(KW, child=(4, 8, 16, 16)),
-               dict(KW, child_block=(5, 4)))
+        bad = (levels(blocks=(B, B, None)), levels(blocks=(B, None, B)),
+               levels(objects=((), (circle(),), ())), levels(l2=(4, 8, 16, 16)),
+               levels(blocks=(B, B, (5, 4))))
         for kw in bad:
             with self.subTest(kw=kw), self.assertRaises(ValueError):
-                FixedPatchStepper(CFG, L1, context=context, **kw)
-        for kw in (dict(child_objects=[child_body()]), dict(child_jets=[child_jet()]),
-                   dict(KW, child_jets=[child_jet()])):
+                FixedPatchStepper(CFG, context=context, **kw)
+        # L2 bodies/Jets without an L2 level (one entry too many), and an L2 Jet without a body.
+        two_level = dict(refinements=[L1], level_blocks=[None, None])
+        for kw in (dict(two_level, level_objects=[(), (), (child_body(),)]),
+                   dict(two_level, level_jets=[(), (), (child_jet(),)]),
+                   levels(jets=((), (), (child_jet(),)))):
             with self.assertRaises(ValueError):
-                FixedPatchStepper(CFG, L1, context=context, **kw)
-        with self.assertRaises(ValueError):  # several L1 patches + child: not yet
-            FixedPatchStepper(LBMConfig(nx=32, ny=16, viscosity=.1), ((4, 4, 12, 12), (20, 4, 28, 12)),
-                              context=context, **KW)
+                FixedPatchStepper(CFG, context=context, **kw)
+        with self.assertRaises(ValueError):  # several L1 patches + scalar child: not yet
+            FixedPatchStepper(LBMConfig(nx=32, ny=16, viscosity=.1), context=context,
+                              **levels(l1=((4, 4, 12, 12), (20, 4, 28, 12))))
 
 
     def test_four_halo_bfl_steps_and_fresh_middle_feeds(self):
@@ -80,11 +92,12 @@ class ThreeLevelCPU(unittest.TestCase):
         f, g = run._levels[1:]
         b = g.boundary
         events, feeds = [], []
-        advance, gather = run._advance_child, run._gather_halo
-        def record_feed(buffer, **kw):
-            self.assertIs(buffer, (f.current, f.spare)[len(feeds)])
-            feeds.append(buffer)
-            advance(buffer, **kw)
+        advance, gather = run._advance, run._gather_halo
+        def record_feed(index, buffer, **kw):  # index 2: L1 hop feeds L2
+            if index == 2:
+                self.assertIs(buffer, (f.current, f.spare)[len(feeds)])
+                feeds.append(buffer)
+            advance(index, buffer, **kw)
         def record_halo(level, buffer, **kw):
             if level is g:
                 events.append(("halo", buffer))
@@ -95,7 +108,7 @@ class ThreeLevelCPU(unittest.TestCase):
             self.assertIs(kind, g.kind)
             events.append(("step", src))
         g.kernel.side_effect = record_step
-        with patch.object(run, "_advance_child", side_effect=record_feed), \
+        with patch.object(run, "_advance", side_effect=record_feed), \
                 patch.object(run, "_gather_halo", side_effect=record_halo):
             run.step()
         self.assertEqual(feeds, [f.current, f.spare])
@@ -105,8 +118,8 @@ class ThreeLevelCPU(unittest.TestCase):
         self.assertGreater(len(np.unique(b.tables["block"])), 1)
         # Negative control: reusing L1's old source at the midpoint must fail.
         feeds.clear()
-        with patch.object(run, "_advance_child", side_effect=lambda buffer, **kw:
-                          record_feed(f.current, **kw)):
+        with patch.object(run, "_advance", side_effect=lambda index, buffer, **kw:
+                          record_feed(index, f.current if index == 2 else buffer, **kw)):
             with self.assertRaises(AssertionError):
                 run.step()
         run.close()
@@ -155,7 +168,7 @@ class ThreeLevelGPU(unittest.TestCase):
     def test_equilibrium_is_kept_on_every_level(self):
         from CelerisLab.cuda.context import CudaContext
         feq = np.asarray(compute_feq_d2q9(1.0, .03, -.02), np.float32)[:, None, None]
-        with CudaContext(0) as ctx, FixedPatchStepper(CFG, L1, context=ctx, **KW) as run:
+        with CudaContext(0) as ctx, FixedPatchStepper(CFG, context=ctx, **KW) as run:
             shapes = ((16, 16), run.patch.fine_shape, run.child_patch.fine_shape)
             run.initialize(*(np.broadcast_to(feq, (9, *s)).copy() for s in shapes))
             run.step(8)
@@ -168,15 +181,16 @@ class ThreeLevelGPU(unittest.TestCase):
 
     def test_nonequilibrium_masks_and_fresh_middle_feeds(self):
         from CelerisLab.cuda.context import CudaContext
-        with CudaContext(0) as ctx, FixedPatchStepper(CFG, L1, context=ctx, **KW) as run:
+        with CudaContext(0) as ctx, FixedPatchStepper(CFG, context=ctx, **KW) as run:
             p1, p2 = run.patch, run.child_patch
             run.initialize(state(16, 16, 1), state(*p1.fine_shape, 2), state(*p2.fine_shape, 3))
             f = run._levels[1]
-            feeds, original = [], run._advance_child
-            def record(buffer, **kw):
-                feeds.append(int(buffer))
-                original(buffer, **kw)
-            with patch.object(run, "_advance_child", side_effect=record):
+            feeds, original = [], run._advance
+            def record(index, buffer, **kw):  # index 2: L1 hop feeds L2
+                if index == 2:
+                    feeds.append(int(buffer))
+                original(index, buffer, **kw)
+            with patch.object(run, "_advance", side_effect=record):
                 cur, spare = int(f.current), int(f.spare)
                 run.step(1)
             self.assertEqual(feeds, [cur, spare])  # current G, then the new G of hop 1
@@ -203,8 +217,9 @@ class ThreeLevelBodyGPU(unittest.TestCase):
             CFG, velocity=0., wall_normal_velocity=.001, wall_slot_width=4,
             y_wall_bc="on_site_velocity", top_wall_bc="reservoir")
         with CudaContext(0) as ctx, FixedPatchStepper(
-                cfg, L1, context=ctx, coarse_boundary=mode, child_objects=[child_body(spec)],
-                child_jets=jets, **dict(KW, child_block=block)) as run:
+                cfg, context=ctx, coarse_boundary=mode,
+                **levels(blocks=(B, B, block), objects=((), (), (child_body(spec),)),
+                         jets=((), (), tuple(jets)))) as run:
             run.initialize(*(state(*level.shape[1:], i + 1) for i, level in enumerate(run._levels)))
             snapshots = []
             for stop in (0, 1, 2, 4, 8):

tests/validation/multigrid/test_refinement_three_level_multipatch_gpu.py

@@ -78,10 +78,10 @@ class ThreeLevelMultipatchGPU(unittest.TestCase):
     def run_case(self, ctx, cfg=CFG, parents=PARENTS, children=CHILDREN,
                  mode='periodic', blocks=((4, 4), (4, 4)), objects=(), drive=(), switch=False,
                  scalar_child=None):
-        kwargs = dict(child_rectangles_in_parent=children) if scalar_child is None else dict(child=scalar_child)
-        with FixedPatchStepper(config(cfg, mode), parents, context=ctx, coarse_boundary=mode,
-                base_block=(4, 4), fine_block=blocks[0], child_block=blocks[1],
-                child_objects=objects, child_jets=drive, **kwargs) as run:
+        child = children if scalar_child is None else scalar_child
+        with FixedPatchStepper(config(cfg, mode), context=ctx, coarse_boundary=mode,
+                refinements=[parents, child], level_blocks=[(4, 4), blocks[0], blocks[1]],
+                level_objects=[(), (), objects], level_jets=[(), (), drive]) as run:
             frame = frames(run)
             run.initialize(*(physical_state(level.shape[1:], *f)
                              for level, f in zip(run._levels, frame)))

tests/validation/multigrid/test_runtime_child_remap_gpu.py

@@ -26,9 +26,8 @@ FP64_ATOL = 3e-6
 
 
 def make(ctx):
-    return FixedPatchStepper(CFG, PARENTS, context=ctx, base_block=(4, 4),
-                             fine_block=(4, 4), child_block=(4, 4),
-                             child_rectangles_in_parent=A)
+    return FixedPatchStepper(CFG, context=ctx, refinements=[PARENTS, A],
+                             level_blocks=[(4, 4)] * 3)
 
 
 def initial(run, uniform):

tests/validation/multigrid/test_shifted_jets_gpu.py

@@ -136,8 +136,8 @@ class ShiftedJetsGPU(unittest.TestCase):
                   Parallel(0.),amplitude=.013)
         for rho in (.99,1.01):
             with self.subTest(rho=rho),CudaContext(0) as ctx:
-                with FixedPatchStepper(cfg,(8,6,24,18),context=ctx,base_block=(4,4),fine_block=(4,4),
-                        fine_objects=(obj,),jets=(whole,),observe_raw_exchange=True) as run:
+                with FixedPatchStepper(cfg,context=ctx,refinements=[(8,6,24,18)],level_blocks=[(4,4)]*2,
+                        level_objects=[(),(obj,)],level_jets=[(),(whole,)],observe_raw_exchange=True) as run:
                     run._initialize_raw(initial(run,rho,u=.013,v=0.))
                     expected=run._download_raw();ledger=Ledger(self,run,1)
                     self.assertTrue(run._level_boundaries[1].tables['aperture'].all())
@@ -153,7 +153,8 @@ class ShiftedJetsGPU(unittest.TestCase):
         obj=circle((16.,12.),2.15);j=drive((16.,12.),2.15)
         for rho in (.99,1.01):
             with self.subTest(rho=rho),CudaContext(0) as ctx,ExitStack() as owned:
-                settings=dict(bounds=(8,6,24,18),context=ctx,base_block=(4,4),fine_block=(4,4),fine_objects=(obj,),jets=(j,))
+                settings=dict(context=ctx,refinements=[(8,6,24,18)],level_blocks=[(4,4)]*2,
+                              level_objects=[(),(obj,)],level_jets=[(),(j,)])
                 measured=owned.enter_context(FixedPatchStepper(cfg,observe_raw_exchange=True,**settings))
                 plain=owned.enter_context(FixedPatchStepper(cfg,**settings))
                 measured._initialize_raw(initial(measured,rho));plain._initialize_raw(initial(plain,rho))
@@ -186,8 +187,9 @@ class ShiftedJetsGPU(unittest.TestCase):
         parents=((4,4,20,28),(24,4,44,28));a=((16,16,32,40),(56,16,72,40));b=(a[0],(60,16,76,40))
         obj=circle((12.,14.),.8);j=drive((12.,14.),.8)
         with CudaContext(0) as ctx,ExitStack() as owned:
-            old=owned.enter_context(FixedPatchStepper(cfg,parents,context=ctx,base_block=(4,4),fine_block=(4,4),
-                child_block=(4,4),child_rectangles_in_parent=a,child_objects=(obj,),child_jets=(j,),observe_raw_exchange=True))
+            old=owned.enter_context(FixedPatchStepper(cfg,context=ctx,refinements=[parents,a],
+                level_blocks=[(4,4)]*3,level_objects=[(),(),(obj,)],level_jets=[(),(),(j,)],
+                observe_raw_exchange=True))
             old._initialize_raw(initial(old,.99));ledger=Ledger(self,old,2)
             for speed in (.002,-.001):old.set_jet_amplitude(0,speed,level=2);ledger.step()
             before=old._download_raw();count=old.step_count

tests/validation/multigrid/test_shifted_remap_gpu.py

@@ -22,9 +22,8 @@ B=((20,16,36,40),)
 
 
 def make(ctx):
-    return FixedPatchStepper(CFG,PARENTS,context=ctx,base_block=(4,4),
-                             fine_block=(4,4),child_block=(4,4),
-                             child_rectangles_in_parent=A)
+    return FixedPatchStepper(CFG,context=ctx,refinements=[PARENTS,A],
+                             level_blocks=[(4,4)]*3)
 
 
 def initial(run):

tests/validation/run_dfg_re20.py

@@ -0,0 +1,222 @@
+"""Steady DFG 2D-1 (Re 20): refined and uniform runs against the official reference intervals.
+
+Not a full benchmark certification. Declared deviations from the official setup:
+pressure-NEQ outlet (``neq_extrap``) instead of do-nothing, local Zou-He inlet.
+Geometry, inflow profile, initial state, refined layout and observation reuse the
+pinned Re100 runner (``run_refined_dfg``) and ``re100_helpers`` unchanged; only the
+lattice viscosity is set for Re 20 (nu = U_lattice * D / 20 at the root level).
+
+Units. The helpers use scaled DFG units with mean inflow speed 1, so
+Cd = 2 Fx / (rho U^2 D) and Cl = 2 Fy / (rho U^2 D) are scale-free, and
+``pressure_probes`` returns dp / (rho U^2). The official p_diff = p(0.15, 0.2) -
+p(0.25, 0.2) uses U = 0.2 m/s, rho = 1, so p_diff = dp * 0.04. Both are reported;
+only p_diff is compared with the official interval. Forces use the existing sign
+convention: F is the force of the fluid on the cylinder, i.e. the refined raw
+exchange impulse (window ledger, ``total.impulse``) or the uniform ``read_force``,
+with x along the inflow and y up from the bottom wall. Cd must be positive, and the
+official Cl is positive (centre 0.20 below the centreline 0.205), so a flipped sign
+shows up as Cl outside its interval.
+
+Sampling. One sample every SAMPLE_TSTAR (t* = U t / D; 0.25 s), taken at the end of
+a completed root step with all levels synchronized; the step index is recorded. Cd
+and Cl are means over the sample interval (window exchange ledger refined, per-batch
+forces uniform), which filters acoustic and step-parity oscillation; p_diff is the
+end-of-interval value at the exact surface points.
+
+Steady rule (our engineering choice, frozen before any run; not official). Over the
+trailing WINDOW_TSTAR (t* 50..60 inclusive, 21 samples), for each of Cd, Cl and
+p_diff: range (max - min) <= 10 % and |least-squares slope * window| <= 2 % of the
+width of its official interval. Absolute limits, so the small Cl is never a divisor;
+the slope term bounds slow monotone drift that the range alone would pass. If the
+rule fails at TSTAR_MAX the run reports "not steady" and gives no interval verdict;
+limits are never relaxed after a run. The verdict uses the window mean, and the
+distance of each mean to its nearest interval edge is reported (negative outside).
+"""
+
+import argparse
+import json
+import math
+import os
+from pathlib import Path
+import sys
+import time
+from tempfile import TemporaryDirectory
+
+import numpy as np
+
+HERE = Path(__file__).resolve().parent
+sys.path.insert(0, str(HERE))
+import run_refined_dfg as rr  # noqa: E402
+
+RE = 20.0
+U_PHYS = 0.2                   # m/s mean inflow; rho = 1
+TSTAR_MAX = 60.0               # 30 s physical
+SAMPLE_TSTAR = 0.5             # 0.25 s
+WINDOW_TSTAR = 10.0            # trailing 5 s, 21 samples
+# Schaefer & Turek (1996), 2D-1 lower/upper bounds.
+BANDS = dict(cd=(5.57, 5.59), cl=(0.0104, 0.0110), p_diff=(0.1172, 0.1176))
+STEADY_RANGE = {k: (hi - lo) / 10 for k, (lo, hi) in BANDS.items()}
+STEADY_SLOPE = {k: (hi - lo) / 50 for k, (lo, hi) in BANDS.items()}
+DEVIATIONS = ("pressure-NEQ outlet (neq_extrap), not do-nothing", "local Zou-He inlet")
+
+_re100_config = rr.config
+
+
+def config(h, diameter, collision="SRT", jet_scenario="none"):
+    """The pinned Re100 configuration with the lattice viscosity set for Re 20."""
+    if jet_scenario != "none":
+        raise ValueError("DFG 2D-1 runs have no Jets")
+    cfg, body, p = _re100_config(h, diameter, collision, jet_scenario)
+    nu = p["mean_speed"] * p["diameter"] / RE
+    cfg["physics"]["viscosity"] = nu
+    return cfg, body, dict(p, viscosity=nu, re=RE)
+
+
+def lattice_parameters(diameter, speed=rr.SPEED):
+    nu = speed * diameter / RE
+    return dict(viscosity=nu, tau=0.5 + 3 * nu, steps=math.ceil(TSTAR_MAX * diameter / speed),
+                interval=round(SAMPLE_TSTAR * diameter / speed))
+
+
+def sample(impulse, n, diameter, dp):
+    den = rr.SPEED**2 * diameter / 2
+    return dict(cd=float(impulse[0] / n / den), cl=float(impulse[1] / n / den),
+                dp_scaled=float(dp), p_diff=float(dp) * U_PHYS**2)
+
+
+def summarize(rows):
+    """Steady rule over the trailing window, then the interval verdict (or none)."""
+    if not rows or rows[-1]["tstar"] < TSTAR_MAX - 1e-9:
+        return dict(status="INCOMPLETE", steady=False, verdict=None)
+    window = [r for r in rows if r["tstar"] >= TSTAR_MAX - WINDOW_TSTAR - 1e-9]
+    t = np.array([r["tstar"] for r in window])
+    ranges = {k: max(r[k] for r in window) - min(r[k] for r in window) for k in BANDS}
+    drifts = {k: abs(np.polyfit(t, [r[k] for r in window], 1)[0]) * WINDOW_TSTAR for k in BANDS}
+    steady = all(ranges[k] <= STEADY_RANGE[k] and drifts[k] <= STEADY_SLOPE[k] for k in BANDS)
+    final = {k: float(np.mean([r[k] for r in window])) for k in BANDS}
+    edge = {k: min(final[k] - BANDS[k][0], BANDS[k][1] - final[k]) for k in BANDS}
+    result = dict(window_samples=len(window), ranges=ranges, drifts=drifts,
+                  range_limits=STEADY_RANGE, slope_limits=STEADY_SLOPE, steady=steady,
+                  window_mean=final, edge_distance=edge, bands=BANDS,
+                  deviations=DEVIATIONS, cd_positive=final["cd"] > 0)
+    if not steady:
+        return dict(result, status="NOT_STEADY", verdict=None)
+    inside = {k: BANDS[k][0] <= final[k] <= BANDS[k][1] for k in BANDS}
+    return dict(result, status="WITHIN_INTERVALS" if all(inside.values()) else "OUTSIDE_INTERVALS",
+                verdict=inside)
+
+
+def healthy(row):
+    return row["max_mach"] <= 0.2 and row["rho_min"] >= 0.5 and row["rho_max"] <= 1.5
+
+
+def run_case(a, h, case):
+    from contextlib import ExitStack
+    from CelerisLab.cuda.context import CudaContext
+    from CelerisLab.lbm.descriptors import FLUID
+    from CelerisLab.lbm.refinement_stepper import FixedPatchStepper
+    from CelerisLab.simulation import Simulation
+
+    refined = case == "refined"
+    cfgdict, bodydict, p = config(h, 40 if refined else 80, a.collision)
+    lp = lattice_parameters(p["diameter"])
+    rows = []
+    with ExitStack() as stack:
+        if refined:
+            cfg, pair, body, host = rr.host_geometry(a.source, h, a.collision)
+            context = stack.enter_context(CudaContext(0))
+            backend = stack.enter_context(FixedPatchStepper(
+                cfg, context=context, coarse_boundary="channel", refinements=[rr.PLACEMENTS["wide"]],
+                level_blocks=[rr.BASE_BLOCK, rr.FINE_BLOCK], level_objects=[(), (body,)],
+                observe_raw_exchange=True, observe_window_exchange=True))
+            from CelerisLab.lbm.channel import channel_masks
+            from CelerisLab.lbm.refinement import ACTIVE
+            from CelerisLab.lbm.descriptors import SOLID
+            masks = [channel_masks(pair.coarse_shape)[0] & ~pair.covered,
+                     (pair.fine_kind == ACTIVE)
+                     & ((host.flags.reshape(pair.fine_shape) & SOLID) == 0)]
+            backend.initialize(rr.initial_state(pair.coarse_shape, (0.0, 0.0), 1.0, root=True),
+                               rr.initial_state(pair.fine_shape, pair.fine_origin, 0.5))
+            probe_p = dict(p, center=[(80.5 - pair.fine_origin[0]) / 0.5 - 0.5,
+                                      (81.0 - pair.fine_origin[1]) / 0.5 - 0.5], radius=40.0)
+        else:
+            tmp = Path(stack.enter_context(TemporaryDirectory()))
+            (tmp / "lbm.json").write_text(json.dumps(cfgdict))
+            (tmp / "body.json").write_text(json.dumps(bodydict))
+            sim = stack.enter_context(Simulation(str(tmp / "lbm.json"), str(tmp / "body.json"),
+                                                 device_id=0))
+            sim.initialize()
+            probe_p = p
+            fluid = (sim.field.flag.reshape(p["ny"], p["nx"]) & FLUID) != 0
+        begin = 0
+        while begin < lp["steps"]:
+            rr.check_deadline(a.deadline)
+            n = min(lp["interval"], lp["steps"] - begin)
+            if refined:
+                impulse = rr.advance_refined_interval(backend, n, a.deadline, "window")
+                fields = [rr.macros(g) for g in backend.download()]
+                rho, ux, uy = fields[1]
+                fluid = masks[1]
+                vals = [tuple(v[m] for v in f) for m, f in zip(masks, fields)]
+            else:
+                impulse, done = np.zeros(2), 0
+                while done < n:
+                    batch = min(100, n - done)
+                    sim.run(batch)
+                    impulse += sim.read_force(0).astype(np.float64) * batch
+                    done += batch
+                m = sim.get_macroscopic()
+                rho, ux, uy = [np.asarray(m[k], np.float64).reshape(p["ny"], p["nx"])
+                               for k in ("rho", "ux", "uy")]
+                vals = [(rho[fluid], ux[fluid], uy[fluid])]
+            begin += n
+            row = dict(step=begin, tstar=begin * rr.SPEED / p["diameter"],
+                       **sample(impulse, n, p["diameter"],
+                                h.pressure_probes(rho, fluid, probe_p)["dp"]),
+                       rho_min=float(min(v[0].min() for v in vals)),
+                       rho_max=float(max(v[0].max() for v in vals)),
+                       max_mach=float(max(np.sqrt(3 * (v[1]**2 + v[2]**2)).max() for v in vals)))
+            rr.ensure_finite(row)
+            rows.append(row)
+            if not healthy(row):
+                break
+    summary = summarize(rows) if healthy(rows[-1]) else dict(status="UNHEALTHY", steady=False,
+                                                             verdict=None)
+    return dict(case=case, collision=a.collision, lattice=lp, rows=rows, **summary)
+
+
+def plan(collision="SRT"):
+    return dict(re=RE, collision=collision, tstar_max=TSTAR_MAX, sample_tstar=SAMPLE_TSTAR,
+                window_tstar=WINDOW_TSTAR, bands=BANDS, range_limits=STEADY_RANGE, slope_limits=STEADY_SLOPE,
+                deviations=DEVIATIONS, pressure_scale=U_PHYS**2,
+                refined_root=lattice_parameters(40), refined_fine_tau=0.5 + 3 * 2 * rr.SPEED * 40 / RE,
+                uniform=lattice_parameters(80),
+                label="compared against the official reference bands (non-canonical neq_extrap outlet, zou_he_local inlet); not a full benchmark certification")
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument("--case", choices=["refined", "uniform", "both"], default="refined")
+    parser.add_argument("--collision", choices=["SRT", "MRT"], default="SRT")
+    parser.add_argument("--source", type=Path, default=rr.DEFAULT_SOURCE)
+    parser.add_argument("--output", type=Path, required=True)
+    parser.add_argument("--plan", action="store_true", help="Write the frozen plan; no CUDA")
+    parser.add_argument("--max-wall-seconds", type=float)
+    a = parser.parse_args()
+    a.source = a.source.resolve()
+    a.output.mkdir(parents=True, exist_ok=False)
+    (a.output / "plan.json").write_text(json.dumps(plan(a.collision), indent=2, allow_nan=False))
+    if a.plan:
+        return
+    if not a.max_wall_seconds or a.max_wall_seconds <= 0 or not os.environ.get("CUDA_VISIBLE_DEVICES"):
+        raise SystemExit("GPU run needs --max-wall-seconds > 0 and explicit CUDA_VISIBLE_DEVICES")
+    h, _ = rr.helpers(a.source)
+    rr.config = config  # host_geometry builds its root configuration through this name
+    a.deadline = time.monotonic() + a.max_wall_seconds
+    cases = ["refined", "uniform"] if a.case == "both" else [a.case]
+    results = [run_case(a, h, case) for case in cases]
+    (a.output / "result.json").write_text(json.dumps(results, indent=2, allow_nan=False))
+
+
+if __name__ == "__main__":
+    main()

tests/validation/run_jet_circle_cv.py

@@ -74,7 +74,25 @@ def cv(g, fluid, origin, rectangle, nu, h=0.5):
     Cauchy stress from centred velocity gradients, NOT postcollision non-equilibrium.
     Rectangle faces lie on cell edges; fluid mask excludes the staircase cylinder.
     """
-    rho, mom, vel = moments(g)
+    return _cv_quantities(*moments(g), fluid, origin, rectangle, nu, h)
+
+
+def cv_from_macros(rho, ux, uy, fluid, origin, rectangle, nu, h=0.5):
+    """Same CV calculation from public macros, in one common length/time frame.
+
+    ``origin`` is the lower cell edge, ``h`` the cell width, and ``nu`` uses
+    that frame. Returns [mass, Px, Py] inventory and outward total flux.
+    Crop fields/mask together and translate origin before calling if desired.
+    No boundary-exchange observation enters this independent estimator.
+    """
+    rho = np.asarray(rho, np.float64)
+    if rho.ndim != 2 or any(np.shape(v) != rho.shape for v in (ux, uy, fluid)):
+        raise ValueError("CV macros and fluid mask must have matching 2D shapes")
+    vel = np.asarray([ux, uy], np.float64)
+    return _cv_quantities(rho, rho[None] * vel, vel, fluid, origin, rectangle, nu, h)
+
+
+def _cv_quantities(rho, mom, vel, fluid, origin, rectangle, nu, h):
     x0, y0, x1, y1 = np.rint((np.array(rectangle) - np.tile(origin, 2)) / h).astype(int)
     np.testing.assert_allclose(
         np.array([x0, y0, x1, y1]) * h + np.tile(origin, 2), rectangle, atol=1e-12
@@ -261,12 +279,11 @@ def run_case(c, ctx, output, provenance, continuation=False):
         PeriodicBlockStepper(fine_cfg, layout, context=ctx, objects=[fobj]) as uniform,
         FixedPatchStepper(
             cfg,
-            c["bounds"],
             context=ctx,
-            base_block=(8, 8),
-            fine_block=(8, 8),
-            fine_objects=[obj],
-            jets=jets,
+            refinements=[c["bounds"]],
+            level_blocks=[(8, 8), (8, 8)],
+            level_objects=[(), (obj,)],
+            level_jets=[(), tuple(jets)],
             observe_raw_exchange=True,
         ) as amr,
     ):

tests/validation/run_refined_dfg.py

@@ -17,8 +17,109 @@ HERE = Path(__file__).resolve().parent
 DEFAULT_SOURCE = HERE.parents[1]
 BOUNDS = (40, 24, 320, 140)
 BASE_BLOCK = (2, 881)  # Exact 166 x 881 domain; no geometric padding.
-FINE_BLOCK = (8, 8)  # 240 x 568 including four fine halo cells.
+FINE_BLOCK = (8, 8)  # Wide 240 x 568 or compact 168 x 168, including fine halos.
 SPEED = 0.01
+JET_PEAK = 0.001
+JET_WINDOWS = [(t, t + 10) for t in range(250, 300, 10)]
+CV_CONTOURS = np.array([(48., 44., 160., 120.), (44., 36., 180., 128.)])
+PLACEMENTS = {"wide": BOUNDS, "compact": (48, 48, 128, 128)}
+COMPACT_CV_CONTOURS = np.array([(52., 52., 112., 112.), (50., 50., 120., 120.)])
+
+
+def selected_cases(selection="both", uniform_diameter=80):
+    return [(case, diameter) for case, diameter in (("uniform", uniform_diameter), ("refined", 40))
+            if selection in ("both", case)]
+
+
+def uniform_origin(diameter):
+    h = 40 / diameter
+    return (.5 - .5*h, 1 - h)
+
+
+def cv_contours(refined, diameter, placement="wide"):
+    contours = CV_CONTOURS if placement == "wide" else COMPACT_CV_CONTOURS
+    return contours if refined else contours + [20/diameter, 0., 20/diameter, 0.]
+
+
+def cv_selected(step, diameter, mode):
+    return mode == "pilot" or round(290 * diameter / SPEED) <= step <= round(300 * diameter / SPEED)
+
+
+def cv_snapshot(rho, ux, uy, fluid, origin, refined, begin, n, diameter, impulse, placement="wide"):
+    """Cropped public macros only; all inventories, fluxes and impulses use root units."""
+    from run_jet_circle_cv import cv_from_macros
+
+    rectangles = cv_contours(refined, diameter, placement)
+    h_cell = .5 if refined else 40 / diameter
+    origin = np.asarray(origin, dtype=float)
+    x0, y0, x1, y1 = np.rint((rectangles[-1] - np.tile(origin, 2)) / h_cell).astype(int)
+    selection = np.s_[y0-2:y1+2, x0-2:x1+2]
+    cropped_origin = origin + h_cell * np.array([x0-2, y0-2])
+    fields = [v[selection] for v in (rho, ux, uy, fluid)]
+    values = [cv_from_macros(*fields, cropped_origin, rect, .004, h=h_cell)
+              for rect in rectangles]
+    h_native = 1.0 if refined else 40 / diameter
+    return dict(step=begin+n, tstar=(begin+n)*SPEED/diameter,
+                time_root=(begin+n)*h_native, interval_start_root=begin*h_native,
+                interval_dt_root=n*h_native,
+                interval_impulse_root=(np.asarray(impulse)*h_native**2).tolist(),
+                inventory=[inventory.tolist() for inventory, _ in values],
+                outward_flux=[flux.tolist() for _, flux in values])
+
+
+def public_jets(center, radius, scenario):
+    """Same physical apertures; caller supplies its public geometry frame."""
+    if scenario == "none":
+        return ()
+    from CelerisLab.body.jets import Jet, Sector, Radial
+
+    peak = 0.0 if scenario == "zero" else JET_PEAK
+    return tuple(
+        Jet(Sector(center, angle, math.pi / 12, radius * 1.005),
+            Radial(center, inward=False), "parabolic", amplitude)
+        for angle, amplitude in ((math.pi / 2, peak), (3 * math.pi / 2, -peak))
+    )
+
+
+def jet_interval(handle, scenario, begin, n, diameter):
+    """Apply a reversal only at a completed interval boundary, before advancing."""
+    if scenario != "none":
+        boundaries = [round(t * diameter / SPEED) for t in (250, 260, 270, 280, 290, 300, 305)]
+        n = min([n] + [step - begin for step in boundaries if step > begin])
+    if scenario != "reverse":
+        return n, None
+    switch = round(300 * diameter / SPEED)
+    if begin < switch:
+        return min(n, switch - begin), None
+    if begin == switch:
+        handle.set_jet_amplitude(0, -JET_PEAK)
+        handle.set_jet_amplitude(1, JET_PEAK)
+        return n, dict(step=begin, tstar=300.0, amplitudes=[-JET_PEAK, JET_PEAK])
+    return n, None
+
+
+def jet_diagnostics(rows, scenario):
+    """Raw interval-weighted diagnostics only; no driven-flow qualification gate."""
+    windows = JET_WINDOWS + ([(300, 305)] if scenario == "reverse" else [])
+    result = []
+    for start, end in windows:
+        selected = [r for r in rows if start <= r["tstar_force"] < end]
+        if not selected:
+            continue
+        if any(2 * r["tstar_force"] - r["tstar"] < start - 1e-9
+               or r["tstar"] > end + 1e-9 for r in selected):
+            raise ValueError("Jet diagnostic interval crosses a window boundary")
+        weights = np.array([2 * (r["tstar"] - r["tstar_force"]) for r in selected])
+        record = dict(start_tstar=start, end_tstar=end, samples=len(selected),
+                      covered_tstar=float(weights.sum()),
+                      complete=bool(np.isclose(weights.sum(), end - start, rtol=0, atol=1e-9)))
+        for key in ("cd", "cl"):
+            values = np.array([r[key] for r in selected])
+            record[key] = dict(mean=float(np.average(values, weights=weights)),
+                               min=float(values.min()), max=float(values.max()),
+                               rms=float(np.sqrt(np.average(values**2, weights=weights))))
+        result.append(record)
+    return result
 
 
 def helpers(source):
@@ -39,26 +140,34 @@ def helpers(source):
     return h, periodic
 
 
-def config(h, diameter, collision="SRT"):
+def config(h, diameter, collision="SRT", jet_scenario="none"):
     cfg, body, p = h.make_config(diameter, SPEED, collision, "neq_extrap", "zou_he_local")
     cfg["method"]["outlet"]["srt_neq_damp"] = 0.5
+    if jet_scenario != "none":
+        if collision != "MRT":
+            raise ValueError("Public Jet scenarios require MRT")
+        cfg["method"]["ddf_shifting"] = False
     return cfg, body, p
 
 
-def plan(h, collision="SRT", observation_mode="last_base_step"):
-    _, _, c = config(h, 40, collision)
-    _, _, f = config(h, 80, collision)
-    x0, y0, x1, y1 = BOUNDS
+def plan(h, collision="SRT", observation_mode="last_base_step", jet_scenario="none", uniform_diameter=80, placement="wide"):
+    _, _, c = config(h, 40, collision, jet_scenario)
+    _, _, f = config(h, uniform_diameter, collision, jet_scenario)
+    bounds = PLACEMENTS[placement]
+    x0, y0, x1, y1 = bounds
     fine_active = 4 * (x1 - x0) * (y1 - y0)
     coarse_uncovered = c["nx"] * c["ny"] - fine_active // 4
     return dict(
         status="prepared_not_run",
         collision=collision,
+        jet_scenario=jet_scenario,
+        ddf_shifting=jet_scenario == "none",
         observation_mode=observation_mode,
         root_gpu_gates_required=True,
         root=c,
         uniform=f,
-        bounds_root_edge=list(BOUNDS),
+        bounds_root_edge=list(bounds),
+        fine_origin_root_edge=[x0 - 2, y0 - 2],
         physical_patch_m=[
             (x0 - 0.5) * c["dx"],
             (y0 - 1) * c["dx"],
@@ -78,19 +187,31 @@ def plan(h, collision="SRT", observation_mode="last_base_step"):
         physical_viscosity_m2_s=0.001,
         finest_dx_m=f["dx"],
         finest_dt_s=f["dt"],
+        refined_finest_dx_m=c["dx"]/2,
+        refined_finest_dt_s=c["dt"]/2,
         approximate_leaf_cell_ratio=(coarse_uncovered + fine_active)
         / (f["nx"] * f["ny"]),
         approximate_collision_work_ratio=(coarse_uncovered + 2 * fine_active)
-        / (2 * f["nx"] * f["ny"]),
+        / ((uniform_diameter/40) * f["nx"] * f["ny"]),
         cost_caveat="Geometry-only estimates include ghosts/solids; exclude block halos, transfers, observation and launch overhead. Not measured speedup.",
-        sampling_offset="For origin (38,22), fine physical x=(j+75.5)*dx80 versus uniform i*dx80: half-fine-cell x offset. Fine physical y=(k+42.5)*dx80 equals uniform (l-.5)*dx80 at l=k+43: y samples align. Body, wall and source planes coincide.",
+        sampling_offset="Uniform nodes map to root edges X=.5+i*(40/D), Y=1+(j-.5)*(40/D). Refined centers are fine_origin_root_edge+(index+.5)*.5. Body, wall and source planes coincide; compare observables, not pointwise arrays.",
         outlet=(
             "SRT pressure NEQ, all nine fneq damped by .5, no backflow clamp; noncanonical DFG outlet"
             if collision == "SRT" else
             "MRT pressure NEQ, unknowns q2/6/8 extrapolated; no backflow clamp; noncanonical DFG outlet"
         ),
-        modes={"pilot_tstar": 5.0, "full_tstar": 300.0},
+        modes={"pilot_tstar": 5.0, "full_tstar": 305.0 if jet_scenario == "reverse" else 300.0},
         observation_dense_tstar=0.02,
+        **(dict(jets=dict(
+            uniform_origin_node=f["center"], refined_origin_root_edge=[80.5, 81.0],
+            angles_rad=[math.pi / 2, 3 * math.pi / 2], half_width_rad=math.pi / 12,
+            radial_extent_over_radius=[0.0, 1.005],
+            field="Radial(outward)", profile="parabolic", condition="velocity",
+            initial_amplitudes=[0.0, 0.0] if jet_scenario == "zero" else [JET_PEAK, -JET_PEAK],
+            reversal_tstar=300.0 if jet_scenario == "reverse" else None,
+            diagnostic_windows_tstar=JET_WINDOWS + ([(300, 305)] if jet_scenario == "reverse" else []),
+            transfer="constant", driven_qualification="not assessed",
+        )) if jet_scenario != "none" else {}),
     )
 
 
@@ -126,7 +247,7 @@ def initial_state(shape, origin, spacing, height=164.0, speed=SPEED, root=False)
     return w * (1 + 3 * cu + 4.5 * cu * cu - 1.5 * velocity * velocity)
 
 
-def host_geometry(source, h, collision="SRT"):
+def host_geometry(source, h, collision="SRT", jet_scenario="none", placement="wide"):
     """Production donor/transfer and complete cut-link checks, without CUDA."""
     from CelerisLab.config import load_lbm_config
     from CelerisLab.lbm.refinement import FixedPatch2D, prepare_fine_boundary
@@ -139,12 +260,12 @@ def host_geometry(source, h, collision="SRT"):
     from CelerisLab.body.geometry.circle import CircleGeometry
     from CelerisLab.body.objects import SimObject
 
-    cfgdict, _, _ = config(h, 40, collision)
+    cfgdict, _, _ = config(h, 40, collision, jet_scenario)
     with TemporaryDirectory() as tmp:
         p = Path(tmp) / "cfg.json"
         p.write_text(json.dumps(cfgdict))
         cfg = load_lbm_config(str(p))
-    pair = FixedPatch2D.from_config(cfg, BOUNDS)
+    pair = FixedPatch2D.from_config(cfg, PLACEMENTS[placement])
     layout = BlockLayout2D.build(cfg.ny, cfg.nx, *BASE_BLOCK)
     validate_channel_config(cfg, [BASE_BLOCK, FINE_BLOCK])
     targets = blocked_base_tables(pair, layout, np.argsort(pair.coalesce_coarse))[1]
@@ -153,18 +274,41 @@ def host_geometry(source, h, collision="SRT"):
     body = SimObject(
         0, geometry=CircleGeometry(80.5, 81.0, 20.0), center=(80.5, 81.0), radius=20.0
     )
-    host = prepare_fine_boundary(cfg, pair, (body,), _shifted_blocked=True)
+    host = prepare_fine_boundary(
+        cfg, pair, (body,), jets=public_jets((80.5, 81.0), 20.0, jet_scenario),
+        _shifted_blocked=jet_scenario == "none",
+    )
     return cfg, pair, body, host
 
 
-def verify_source(source, collision="SRT", observation_mode="last_base_step"):
+def verify_source(source, collision="SRT", observation_mode="last_base_step", jet_scenario="none", observe_cv=False):
     if collision not in ("SRT", "MRT"):
         raise ValueError("Matched collision must be SRT or MRT")
     if observation_mode not in ("last_base_step", "window"):
         raise ValueError("Unknown refined observation mode")
+    if observe_cv and jet_scenario == "none":
+        raise ValueError("--observe-cv requires an explicit public Jet scenario")
     name = ("source_manifest_window.json" if observation_mode == "window" else
             "source_manifest.json" if collision == "SRT" else "source_manifest_mrt.json")
     expected = json.loads((HERE / "data/refined_dfg" / name).read_text())
+    if jet_scenario != "none":
+        if collision != "MRT" or observation_mode != "window":
+            raise ValueError("Public Jet scenarios require MRT and --exchange-window")
+        import subprocess
+        sys.path.insert(0, str(HERE))
+        from source_provenance import checkout_provenance
+
+        paths = set(expected["sha256"])
+        if observe_cv:
+            paths.add("tests/validation/run_jet_circle_cv.py")
+        paths.update(subprocess.check_output(
+            ["git", "-C", str(source), "ls-files", "src"], text=True).splitlines())
+        return dict(
+            source_capture="current checkout, not historical DFG qualification",
+            **checkout_provenance(source), observation_mode=observation_mode,
+            sha256={name: hashlib.sha256((source / name).read_bytes()).hexdigest()
+                    for name in sorted(paths)},
+        )
     for name, digest in expected["sha256"].items():
         if hashlib.sha256((source / name).read_bytes()).hexdigest() != digest:
             raise RuntimeError("Source mismatch: " + name)
@@ -219,29 +363,32 @@ def run_case(a, h, periodic, case):
     from contextlib import ExitStack
 
     refined = case == "refined"
-    cfgdict, bodydict, p = config(h, 40 if refined else 80, a.collision)
-    cap = 5.0 if a.mode == "pilot" else 300.0
+    cfgdict, bodydict, p = config(h, 40 if refined else a.uniform_diameter, a.collision, a.jet_scenario)
+    cap = 5.0 if a.mode == "pilot" else (305.0 if a.jet_scenario == "reverse" else 300.0)
     max_steps = math.ceil(cap * p["diameter"] / SPEED)
     rows = []
     healthy = True
     step_seconds = 0.0
+    cv_seconds, cv_samples = 0.0, 0
+    amplitude_changes = []
     started = time.monotonic()
     check_deadline(a.deadline)
     dest = a.output / case
     dest.mkdir()
     with ExitStack() as stack:
+        cv_out = stack.enter_context((dest / "cv_history.jsonl").open("w")) if a.observe_cv else None
         if refined:
-            cfg, pair, body, host = host_geometry(a.source, h, a.collision)
+            cfg, pair, body, host = host_geometry(a.source, h, a.collision, a.jet_scenario, a.placement)
             context = stack.enter_context(CudaContext(0))
             backend = stack.enter_context(
                 FixedPatchStepper(
                     cfg,
-                    BOUNDS,
                     context=context,
                     coarse_boundary="channel",
-                    base_block=BASE_BLOCK,
-                    fine_block=FINE_BLOCK,
-                    fine_objects=(body,),
+                    refinements=[PLACEMENTS[a.placement]],
+                    level_blocks=[BASE_BLOCK, FINE_BLOCK],
+                    level_objects=[(), (body,)],
+                    level_jets=[(), public_jets((80.5, 81.0), 20.0, a.jet_scenario)],
                     observe_raw_exchange=True,
                     **({"observe_window_exchange": True} if a.observation_mode == "window" else {}),
                 )
@@ -274,6 +421,9 @@ def run_case(a, h, periodic, case):
             sim = stack.enter_context(
                 Simulation(str(tmp / "lbm.json"), str(tmp / "body.json"), device_id=0)
             )
+            for index, jet in enumerate(public_jets(p["center"], p["radius"], a.jet_scenario)):
+                if sim.add_jet(jet) != index:
+                    raise RuntimeError("Unexpected public Jet registration index")
             sim.initialize()
             probe_p = p
             fluid = (sim.field.flag.reshape(p["ny"], p["nx"]) & FLUID) != 0
@@ -290,6 +440,10 @@ def run_case(a, h, periodic, case):
                     else 0.5
                 )
                 n = min(max(1, round(width * p["diameter"] / SPEED)), max_steps - begin)
+                n, change = jet_interval(backend if refined else sim, a.jet_scenario,
+                                         begin, n, p["diameter"])
+                if change is not None:
+                    amplitude_changes.append(change)
                 impulse = np.zeros(2)
                 tick = time.monotonic()
                 if refined:
@@ -359,6 +513,19 @@ def run_case(a, h, periodic, case):
                     / SPEED,
                     **h.pressure_probes(rho, fluid, probe_p),
                 )
+                if a.jet_scenario != "none":
+                    row.update(step_start=begin, tstar_start=begin * SPEED / p["diameter"],
+                               interval_steps=n, impulse_x=float(impulse[0]),
+                               impulse_y=float(impulse[1]))
+                if a.observe_cv and cv_selected(begin+n, p["diameter"], a.mode):
+                    tick = time.monotonic()
+                    record = cv_snapshot(rho, ux, uy, fluid,
+                                         pair.fine_origin if refined else uniform_origin(p["diameter"]),
+                                         refined, begin, n, p["diameter"], impulse, a.placement)
+                    cv_out.write(json.dumps(record, allow_nan=False) + "\n")
+                    cv_out.flush()
+                    cv_samples += 1
+                    cv_seconds += time.monotonic() - tick
                 check_deadline(a.deadline)
                 ensure_finite(row)
                 rows.append(row)
@@ -402,14 +569,24 @@ def run_case(a, h, periodic, case):
         steps=begin,
         startup_seconds=startup,
         step_seconds=step_seconds,
+        observation_and_overhead_seconds=time.monotonic() - started - startup - step_seconds,
         wall_seconds=time.monotonic() - started,
         force="raw stationary-body link momentum reaction, per-unit-depth; average over entire observation interval; normalized in each base lattice",
         mass_units="rho_reference * m^2 per unit depth",
         flux_units="rho_reference * m^2/s per unit depth",
         pressure="postcollision end-sample; physical pressure difference / (rho_reference * 1 m/s squared)",
         suite_validated=False,
-        **periodic.assess(rows),
+        **(periodic.assess(rows) if a.jet_scenario in ("none", "zero") else
+           dict(periodic=False, checks={}, cycles=[])),
     )
+    if a.jet_scenario != "none":
+        result.update(jet_diagnostic_windows=jet_diagnostics(rows, a.jet_scenario),
+                      amplitude_changes=amplitude_changes,
+                      pressure_classification=("DFG reference verdict retained, including pressure"
+                          if a.jet_scenario == "zero" else "diagnostic only; no official DFG reference gate"))
+    if a.observe_cv:
+        result.update(cv_observation_seconds=cv_seconds, cv_samples=cv_samples,
+                      cv_qualification="not assessed; scalar observations only")
     if not healthy:
         result["periodic"] = False
     reference = json.loads(
@@ -425,7 +602,8 @@ def run_case(a, h, periodic, case):
         else (
             "pilot_complete"
             if a.mode == "pilot"
-            else ("periodic" if result["periodic"] else "incomplete_periodicity")
+            else ("driven_diagnostics_complete" if a.jet_scenario in ("fixed", "reverse") else
+                  "periodic" if result["periodic"] else "incomplete_periodicity")
         )
     )
     (dest / "summary.json").write_text(json.dumps(result, indent=2, allow_nan=False))
@@ -464,27 +642,39 @@ def check_deadline(deadline):
         )
 
 
-def verify_pilot(path, manifest, collision="SRT", observation_mode="last_base_step"):
+def verify_pilot(path, manifest, collision="SRT", observation_mode="last_base_step", jet_scenario="none", observe_cv=False,
+                 case_selection="both", uniform_diameter=80, placement="wide"):
     if path is None:
         raise ValueError(
             "Full comparison requires --pilot-results from a completed matched pilot"
         )
     previous = read_finite_json(path / "plan.json")
+    options = dict(case_selection=(case_selection, "both"), uniform_diameter=(uniform_diameter, 80), placement=(placement, "wide"))
+    if any(previous.get(k, default) != expected for k, (expected, default) in options.items()):
+        raise ValueError("Pilot case, resolution or placement differs")
+    if previous.get("observe_cv", False) != observe_cv:
+        raise ValueError("Pilot CV observation mode differs")
+    if previous.get("jet_scenario", "none") != jet_scenario:
+        raise ValueError("Pilot Jet scenario differs")
     if previous.get("observation_mode") != observation_mode:
         raise ValueError("Pilot observation mode differs")
     if previous.get("collision") != collision:
         raise ValueError("Pilot collision differs")
     if previous["source_manifest"] != manifest or previous["bounds_root_edge"] != list(
-        BOUNDS
+        PLACEMENTS[placement]
     ):
         raise ValueError("Pilot source or frozen geometry differs")
     if previous.get("runner_sha256") != runner_hash():
         raise ValueError("Pilot runner differs")
     calibrated_seconds = 0.0
-    for case, diameter in (("uniform", 80), ("refined", 40)):
+    for case, diameter in selected_cases(case_selection, uniform_diameter):
         summary = read_finite_json(path / case / "summary.json")
         if (
-            summary.get("observation_mode") != observation_mode
+            any(summary.get(k, default) != expected for k, (expected, default) in options.items())
+            or summary.get("observe_cv", False) != observe_cv
+            or (observe_cv and summary.get("cv_samples") != 250)
+            or summary.get("jet_scenario", "none") != jet_scenario
+            or summary.get("observation_mode") != observation_mode
             or summary.get("collision") != collision
             or summary.get("case") != case
             or summary.get("mode") != "pilot"
@@ -537,7 +727,10 @@ def verify_pilot(path, manifest, collision="SRT", observation_mode="last_base_st
                 raise ValueError("Unhealthy pilot observations")
         ready = read_finite_json(path / case / "ready.json")
         if (
-            ready.get("observation_mode") != observation_mode
+            any(ready.get(k, default) != expected for k, (expected, default) in options.items())
+            or ready.get("observe_cv", False) != observe_cv
+            or ready.get("jet_scenario", "none") != jet_scenario
+            or ready.get("observation_mode") != observation_mode
             or ready.get("collision") != collision
             or ready.get("case") != case
             or ready.get("mode") != "pilot"
@@ -555,9 +748,9 @@ def verify_pilot(path, manifest, collision="SRT", observation_mode="last_base_st
             or not 0 < stepping <= wall
         ):
             raise ValueError("Invalid pilot calibration timings")
-        # Full physical duration is 60 times pilot; dense pilot sampling makes
+        # Full duration is 60 (or 61 with reversal) times pilot; dense sampling makes
         # this conservative for the sparser early full observations. Not a guarantee.
-        calibrated_seconds += startup + 60 * (wall - startup)
+        calibrated_seconds += startup + (61 if jet_scenario == "reverse" else 60) * (wall - startup)
     return 3 * calibrated_seconds
 
 
@@ -566,6 +759,13 @@ def main():
     parser.add_argument("--exchange-window", action="store_true",
                         help="Opt in to refined window-ledger observations on the pinned candidate")
     parser.add_argument("--collision", choices=["SRT", "MRT"], default="SRT")
+    parser.add_argument("--case", choices=["both", "uniform", "refined"], default="both")
+    parser.add_argument("--uniform-diameter", type=int, choices=[80, 160], default=80)
+    parser.add_argument("--placement", choices=list(PLACEMENTS), default="wide")
+    parser.add_argument("--jet-scenario", choices=["none", "zero", "fixed", "reverse"],
+                        default="none", help="Opt in to public unshifted MRT Jets; reverse switches at t*=300 and ends at 305")
+    parser.add_argument("--observe-cv", action="store_true",
+                        help="Record independent cropped-macro CV samples during pilot or full t*=290..300")
     parser.add_argument("--source", type=Path, default=DEFAULT_SOURCE)
     parser.add_argument("--output", type=Path, required=True)
     parser.add_argument("--mode", choices=["plan", "pilot", "full"], default="plan")
@@ -577,15 +777,26 @@ def main():
         help="Required explicit campaign wall-time ceiling for GPU execution",
     )
     a = parser.parse_args()
+    if a.uniform_diameter == 160 and a.case != "uniform":
+        raise ValueError("D160 requires --case uniform; no matched-resolution claim")
+    if a.placement == "compact" and a.case != "refined":
+        raise ValueError("Compact placement requires --case refined")
+    if (a.uniform_diameter != 80 or a.placement != "wide") and a.jet_scenario == "none":
+        raise ValueError("Resolution/placement variants require an explicit public Jet scenario")
     a.source = a.source.resolve()
     a.observation_mode = "window" if a.exchange_window else "last_base_step"
-    manifest = verify_source(a.source, a.collision, a.observation_mode)
+    manifest = verify_source(a.source, a.collision, a.observation_mode, a.jet_scenario, a.observe_cv)
     h, periodic = helpers(a.source)
     from source_provenance import checkout_provenance
 
     a.provenance = checkout_provenance(a.source)
+    a.provenance.update(jet_scenario=a.jet_scenario, ddf_shifting=a.jet_scenario == "none")
+    a.provenance.update(case_selection=a.case, uniform_diameter=a.uniform_diameter, placement=a.placement)
+    if a.observe_cv:
+        a.provenance["observe_cv"] = True
     calibration = (
-        verify_pilot(a.pilot_results, manifest, a.collision, a.observation_mode)
+        verify_pilot(a.pilot_results, manifest, a.collision, a.observation_mode, a.jet_scenario, a.observe_cv,
+                     a.case, a.uniform_diameter, a.placement)
         if a.mode == "full" else None
     )
     if a.mode != "plan" and (
@@ -602,17 +813,31 @@ def main():
     if a.output.exists() and any(a.output.iterdir()):
         raise ValueError("Output must be empty/new")
     a.output.mkdir(parents=True, exist_ok=True)
-    specification = plan(h, a.collision, a.observation_mode)
+    specification = plan(h, a.collision, a.observation_mode, a.jet_scenario, a.uniform_diameter, a.placement)
     specification.update(
         source_manifest=manifest,
         **a.provenance,
-        gates=periodic.GATES,
-        reference_gates=periodic.REFERENCE_GATES,
+        gates=periodic.GATES if a.jet_scenario in ("none", "zero") else None,
+        reference_gates=periodic.REFERENCE_GATES if a.jet_scenario in ("none", "zero") else None,
         runner_sha256=runner_hash(),
         wall_time_budget_seconds=budget,
         full_pilot_calibration_seconds=calibration,
     )
-    host_geometry(a.source, h, a.collision)
+    if a.observe_cv:
+        specification["cv_observation"] = dict(
+            full_tstar=[290, 300], pilot_tstar=[.02, 5], spacing_tstar=.02,
+            refined_contours_root=cv_contours(True, 40, a.placement).tolist(),
+            uniform_contours_root=cv_contours(False, a.uniform_diameter, a.placement).tolist(),
+            uniform_grid_origin_root=uniform_origin(a.uniform_diameter),
+            refined_grid_origin_root=specification["fine_origin_root_edge"],
+            cell_width_root={"uniform": 40/a.uniform_diameter, "refined": .5},
+            viscosity_root=.004, components=["mass", "Px", "Py"],
+            units="root lattice per unit depth; outward flux per root time",
+            interval="Impulse belongs to the interval ending at each snapshot; first retained endpoint (pilot .02, full 290) supplies initial inventory only: exclude its preceding impulse",
+            qualification="not assessed; trapezoidal integration and time-coarsening are offline",
+        )
+    if a.case != "uniform":
+        host_geometry(a.source, h, a.collision, a.jet_scenario, a.placement)
     (a.output / "plan.json").write_text(json.dumps(specification, indent=2))
     if a.mode == "plan":
         return 0
@@ -621,8 +846,9 @@ def main():
             "GPU execution blocked: root GPU gates approval and explicit device selection required"
         )
     results = []
+    cases = selected_cases(a.case, a.uniform_diameter)
     a.deadline = time.monotonic() + budget
-    for case in ("uniform", "refined"):
+    for case, _ in cases:
         try:
             result = run_case(a, h, periodic, case)
         except TimeoutError as exc:
@@ -650,7 +876,12 @@ def main():
         status="pilot_only" if a.mode == "pilot" else "incomplete",
         matched_case_pass=False,
     )
-    if len(results) == 2 and all(r["healthy"] and r["periodic"] for r in results):
+    if a.jet_scenario in ("fixed", "reverse"):
+        comparison.update(status=("pilot_only" if a.mode == "pilot" else "driven_diagnostics_complete")
+                          if len(results) == len(cases) and all(r["healthy"] for r in results) else "invalid_state",
+                          qualification="not assessed; execution completion is not physical acceptance",
+                          jet_diagnostic_windows={r["case"]: r["jet_diagnostic_windows"] for r in results})
+    if a.case == "both" and len(results) == 2 and all(r["healthy"] and r["periodic"] for r in results):
         comparison.update(
             status="periodic_comparison",
             refined_vs_uniform=periodic.compare(
@@ -660,14 +891,20 @@ def main():
         comparison["matched_case_pass"] = comparison["refined_vs_uniform"][
             "reference_agreement"
         ]
+    if a.case != "both":
+        comparison.update(status="single_case_" + results[0]["status"],
+                          own_reference_comparison=results[0].get("reference_comparison"))
     (a.output / "comparison.json").write_text(
         json.dumps(comparison, indent=2, allow_nan=False)
     )
     return (
         0
-        if len(results) == 2
+        if len(results) == len(cases)
         and all(r["healthy"] for r in results)
-        and (a.mode == "pilot" or comparison["matched_case_pass"])
+        and (a.mode == "pilot" or comparison["matched_case_pass"]
+             or a.jet_scenario in ("fixed", "reverse")
+             or (a.case != "both" and results[0]["periodic"]
+                 and results[0].get("reference_comparison", {}).get("reference_agreement", False)))
         else 2
     )
 

tests/validation/taylor_green/assess_projected_pairs.py

@@ -1,7 +1,6 @@
 """New-source four-case repeat of 11901a7; frozen oracle and gates are unchanged."""
 
 import argparse
-import hashlib
 import json
 import math
 from pathlib import Path
@@ -9,25 +8,16 @@ from pathlib import Path
 from assess import BASELINE_FACTOR, FLOORS
 from oracle import LIMITS, TIMES, U, rectangles
 from run_case import (INITIALIZATION, sample_steps, NUMERICAL_REVISION, SOURCE_SHA256,
-                      BUILD_CAPTURE_SHA256, REFERENCE_HARNESS, SCALED_DIAGNOSTIC)
+                      BUILD_CAPTURE_SHA256, REFERENCE_HARNESS)
 
-# Host-generated snapshots of a135252 at the frozen local configurations.
+# Host-generated snapshots of a135252 at the frozen two local configurations.
 # These describe expected inputs; actual sidecars are captured before cleanup.
 BUILD_SOURCES = {
     128: "803177416b7599ab89cc5afd35cf4a28a673b2f4bb8e8a6a1abc0b6d77610873",
     256: "17ec5e60f87b840d3d13b8778bc8a3aecf485469c5a061af46c5cc19b73396cf",
-    512: "4e85e38098858ec95c137d1b1e96846a58d9cf3cc242b349a3ad7c8b8e3ce0aa",
 }
 CASES = ((100, 128, 1, "constant"), (100, 256, 1, "constant"),
          (100, 128, 2, "constant"), (100, 128, 2, "projected_linear"))
-REFERENCE_REVISION = "2cf9853952e52f59bea63cf5c1d3a1cd76e53eed"
-# Audited 2cf9853 scalar receipts, archived at evidence commit 90849a55cad4a0da9b72747da7bfe6eb75962a44.
-REFERENCE_RECEIPTS = {
-    "uniform128": "724efafc267eaa59dcc59e8d4c16177b67f6c6a08fd2732a481833237bb19cee",
-    "uniform256": "3c312a99ebf747a135674dd481b77455a3d2c9a406ca388f30524b37dad9bbe9",
-    "constant128": "2ee28efd1e81b2e28b7902b6c4f95bb2c1ea4e5f0ec484638fa5ae83dca34bba",
-    "projected128": "ee67b1d4d90a048c0d3d1a16447c6eab3d89c94d151f791306e373f96dd8b963",
-}
 NUMERICS = dict(lattice_model="D2Q9", collision="SRT", store_precision="FP32",
                 ddf_shifting=True, streaming="double_buffer", les_enabled=False,
                 boundary="periodic", block_shape=[8, 8],
@@ -83,11 +73,7 @@ def valid_builds(record, n, depth):
     return True
 
 
-def assess(records, expected_revision=None, *, diagnostic=None):
-    if diagnostic not in (None, SCALED_DIAGNOSTIC):
-        raise ValueError("Unknown diagnostic")
-    base_n = 256 if diagnostic else 128
-    cases = tuple((re, n * base_n // 128, depth, scheme) for re, n, depth, scheme in CASES)
+def assess(records, expected_revision=None):
     indexed, duplicates = {}, []
     for record in records:
         key = tuple(record.get(k) for k in ("re_L", "n", "depth", "explosion"))
@@ -95,11 +81,9 @@ def assess(records, expected_revision=None, *, diagnostic=None):
             duplicates.append(str(key))
         else:
             indexed[key] = record
-    missing = [str(k) for k in cases if k not in indexed]
-    checks = dict(complete_matrix=not missing, no_extra_cases=set(indexed) <= set(cases),
+    missing = [str(k) for k in CASES if k not in indexed]
+    checks = dict(complete_matrix=not missing, no_extra_cases=set(indexed) <= set(CASES),
                   no_duplicate_cases=not duplicates, finite_receipts=finite_tree(records))
-    if diagnostic or any("diagnostic" in r for r in records):
-        checks["diagnostic_identity"] = all(r.get("diagnostic") == diagnostic for r in records)
     sources = [r.get("source", {}) for r in records]
     checks["same_source_and_harness"] = bool(sources) and len({
         json.dumps(s, sort_keys=True) for s in sources}) == 1
@@ -122,11 +106,9 @@ def assess(records, expected_revision=None, *, diagnostic=None):
     ) and len(set(devices)) == 1
     enabled = [r.get("early_pressure", {}).get("enabled") for r in records]
     checks["same_early_sampling"] = bool(enabled) and all(type(v) is bool for v in enabled) and len(set(enabled)) == 1
-    if diagnostic:
-        checks["diagnostic_early_sampling"] = all(v is True for v in enabled)
     shared_valid = all(checks.values())
     complete, case_valid, early = {}, {}, []
-    for key in cases:
+    for key in CASES:
         if key not in indexed:
             continue
         r = indexed[key]
@@ -153,7 +135,7 @@ def assess(records, expected_revision=None, *, diagnostic=None):
             (("module", "__init__.py"), ("compiler", "cuda/compiler_v2.py"), ("kernel_root", "lbm/kernels")))
         expected_patch = [] if depth == 1 else rectangles(n, depth)
         checks[label + " patch"] = json.dumps(r.get("refinements")) == json.dumps(expected_patch)
-        cells = [n*n] if depth == 1 else [17*n*n//32, 15*n*n//8]
+        cells = [n*n] if depth == 1 else [8704, 30720]
         hops = [16*n * 2**l for l in range(depth)]
         work = r.get("workload", {})
         checks[label + " workload"] = (
@@ -186,22 +168,19 @@ def assess(records, expected_revision=None, *, diagnostic=None):
 
     comparisons, scheme_results = [], {}
     for scheme in ("constant", "projected_linear"):
-        key = (100, base_n, 2, scheme)
+        key = (100, 128, 2, scheme)
         for metric, floor in FLOORS.items():
-            amr, coarse, fine = (worst(k, metric) for k in (key, cases[0], cases[1]))
+            amr, coarse, fine = (worst(k, metric) for k in (key, CASES[0], CASES[1]))
             budget = None if coarse is None else max(BASELINE_FACTOR * coarse, floor)
             budget = budget if finite(budget) else None
             ratio = None if amr is None or fine is None else amr / max(fine, 1e-30)
             passed = amr is not None and budget is not None and amr <= budget
             checks[f"baseline {scheme}/{metric}"] = passed
             comparisons.append(dict(explosion=scheme, metric=metric, amr=amr,
-                                    baseline_budget=budget, passed=passed,
-                                    **{f"uniform{base_n}": coarse, f"uniform{2*base_n}": fine,
-                                       f"amr_to_uniform{2*base_n}": ratio if finite(ratio) else None}))
-            if diagnostic:
-                comparisons[-1]["floor_dominates"] = None if coarse is None else floor >= BASELINE_FACTOR * coarse
+                                    uniform128=coarse, baseline_budget=budget, passed=passed,
+                                    uniform256=fine, amr_to_uniform256=ratio if finite(ratio) else None))
         baseline_passed = all(checks[f"baseline {scheme}/{metric}"] for metric in FLOORS)
-        valid = shared_valid and all(case_valid.get(k, False) for k in (cases[0], cases[1], key))
+        valid = shared_valid and all(case_valid.get(k, False) for k in (CASES[0], CASES[1], key))
         scheme_results[scheme] = dict(passed=valid and baseline_passed,
                                      valid_case_and_controls=valid, baseline_passed=baseline_passed)
     return dict(passed=all(checks.values()), missing=missing, duplicates=duplicates, checks=checks,
@@ -211,89 +190,19 @@ def assess(records, expected_revision=None, *, diagnostic=None):
                 floors=FLOORS, baseline_factor=BASELINE_FACTOR,
                 main_statistic="maximum of four post-initial samples at t*=.12,.24,.36,.48",
                 early_statistic="sampled pressure maximum only, t*=k*.001875, k=0..64; not an all-step or continuous maximum",
-                finest_control=f"uniform{2*base_n} and AMR/ uniform{2*base_n} ratios are descriptive, not acceptance gates",
+                finest_control="uniform256 and AMR/ uniform256 ratios are descriptive, not acceptance gates",
                 scope="2D periodic Re100 smooth-decay diagnostic; no new algorithm, convergence-order or general AMR qualification")
 
 
-def load_reference(paths):
-    """Use the four audited historical files verbatim, never relabel them fresh controls."""
-    blobs = [path.read_bytes() for path in paths]
-    hashes = [hashlib.sha256(blob).hexdigest() for blob in blobs]
-    if len(hashes) != 4 or set(hashes) != set(REFERENCE_RECEIPTS.values()):
-        raise ValueError("Historical N128 receipt hashes differ from the audited 2cf9853 evidence")
-    return [json.loads(blob) for blob in blobs]
-
-
-def resolution_trend(records, reference, expected_revision):
-    """Signed changes are descriptive; they never replace the frozen acceptance budgets."""
-    old = assess(reference, REFERENCE_REVISION)
-    new = assess(records, expected_revision, diagnostic=SCALED_DIAGNOSTIC)
-    # Numerical screen failures still have useful raw errors; only malformed inputs block trends.
-    valid = all(v for result in (old, new) for k, v in result["checks"].items()
-                if not k.startswith("baseline ") and not k.endswith(" absolute"))
-    valid = valid and all(maximum(r["rows"], m) is not None for r in reference + records for m in LIMITS)
-    oracle = reference[0]["source"]["harness_sha256"].get("oracle.py") if valid else None
-    valid = valid and bool(oracle) and records[0]["source"]["harness_sha256"].get("oracle.py") == oracle
-    if not valid:
-        return dict(valid=False, per_time=[], worst_post_initial=[], uniform256_bridge=[])
-    key = lambda r: (r["re_L"], r["n"], r["depth"], r["explosion"])
-    before, after = {key(r): r for r in reference}, {key(r): r for r in records}
-
-    def change(role, metric, low, high, **extra):
-        ratio = high / low if low else None
-        percent = 100*(ratio-1) if ratio is not None else None
-        return dict(role=role, metric=metric, n128_campaign_error=low, n256_campaign_error=high,
-                    signed_change=high-low, new_to_old=ratio if finite(ratio) else None,
-                    ratio_unavailable_reason=None if finite(ratio) else "zero historical error" if not low else "overflow",
-                    change_percent=percent if finite(percent) else None, **extra)
-
-    per_time, worst, bridge = [], [], []
-    for old_key, role in zip(CASES, ("uniform_root", "uniform_fine", "constant", "projected_linear")):
-        re, n, depth, scheme = old_key
-        low, high = before[old_key], after[(re, 2*n, depth, scheme)]
-        for metric in LIMITS:
-            per_time.extend(change(role, metric, a[metric], b[metric], tstar=a["tstar"])
-                            for a, b in zip(low["rows"], high["rows"]))
-            worst.append(change(role, metric, maximum(low["rows"][1:], metric),
-                                maximum(high["rows"][1:], metric)))
-    for a, b in zip(before[CASES[1]]["rows"], after[CASES[1]]["rows"]):
-        bridge.extend(dict(metric=m, tstar=a["tstar"], historical=a[m], fresh=b[m], signed_change=b[m]-a[m])
-                      for m in LIMITS)
-    low, high = before[CASES[1]], after[CASES[1]]
-    bridge_identity = dict(main_rows_identical=low["rows"] == high["rows"],
-                           early_pressure_rows_identical=low["early_pressure"]["rows"] == high["early_pressure"]["rows"])
-    same_runtime = reference[0]["runtime_identity"] == records[0]["runtime_identity"]
-    return dict(valid=True, reference_revision=REFERENCE_REVISION, reference_receipt_sha256=REFERENCE_RECEIPTS,
-                reference_scheme_results=old["scheme_results"], per_time=per_time, worst_post_initial=worst,
-                uniform256_bridge=bridge, uniform256_bridge_identity=bridge_identity,
-                same_recorded_runtime=same_runtime,
-                trend_interpretation_ready=all(bridge_identity.values()) and same_runtime,
-                scope="Historical same-production/oracle reference versus fresh controls; same-placement two-resolution trend only, not convergence order or phase robustness")
-
-
 if __name__ == "__main__":
     p = argparse.ArgumentParser(description=__doc__)
     p.add_argument("files", type=Path, nargs="+")
     p.add_argument("--output", type=Path, required=True)
     p.add_argument("--expected-revision", required=True)
-    p.add_argument("--diagnostic", choices=[SCALED_DIAGNOSTIC])
-    p.add_argument("--reference-files", type=Path, nargs=4)
     args = p.parse_args()
     if args.output.exists():
         p.error("Output already exists; choose a new path to retain prior evidence")
-    if bool(args.diagnostic) != bool(args.reference_files):
-        p.error("--diagnostic scaled_n256 requires --reference-files; references are diagnostic-only")
-    records = [json.loads(path.read_text()) for path in args.files]
-    result = assess(records, args.expected_revision, diagnostic=args.diagnostic)
-    if args.diagnostic:
-        try:
-            reference = load_reference(args.reference_files)
-        except ValueError as exc:
-            p.error(str(exc))
-        result["diagnostic"] = args.diagnostic
-        result["resolution_trend"] = resolution_trend(records, reference, args.expected_revision)
-        result["checks"]["valid_historical_reference_and_trend"] = result["resolution_trend"]["valid"]
-        result["passed"] = all(result["checks"].values())
+    result = assess([json.loads(path.read_text()) for path in args.files], args.expected_revision)
     args.output.write_text(json.dumps(result, indent=2, allow_nan=False) + "\n")
     print(json.dumps(result, indent=2, allow_nan=False))
     raise SystemExit(0 if result["passed"] else 1)

tests/validation/taylor_green/assess_shear_wave.py

@@ -1,336 +0,0 @@
-"""Fixed four-case shear-wave contracts.
-
-Default: N128 (U128, U256, constant R128, projected R128). Opt-in
---diagnostic scaled_shear_n256: N256 (U256, U512, constant R256, projected
-R256), same physical rectangle, t* schedule, nu = U N / 100, eps(N), limits
-and floors, plus a descriptive comparison with the hash-pinned N128 receipts.
-
-Shared provenance, build, workload and sample-time checks are reused from
-assess_projected_pairs (same cases, source pins and geometry); only the
-Taylor-Green-specific checks are replaced by shear-wave metadata and physics.
-"""
-
-import argparse
-import hashlib
-import json
-import math
-from pathlib import Path
-
-import assess_projected_pairs as tg
-import shear_wave as sw
-import shear_nested as nested
-import shear_twin as twin
-from run_case import (NESTED_SHEAR, SCALED_DIAGNOSTIC, SCALED_SHEAR, SHEAR_NESTED_SHA256,
-                      SHEAR_TWIN_SHA256, SHEAR_WAVE_SHA256, TWIN_SHEAR, sample_steps)
-
-# Audited de5b0cc N128 receipts (evidence commit cba6bca, shear-wave-de5b0cc zip).
-REFERENCE_REVISION = "de5b0cc080794d0ce44d37f845aa8e8dbf8c2016"
-REFERENCE_RECEIPTS = {
-    "uniform128": "d4a60fb806d04bfa8098a862cceba51e00b49979a6a250fef17a5fc8e3ea3255",
-    "uniform256": "e0b58e734724be5f82ee5d6df84395e3181b4e96e4246dd5a574ea23a8d12386",
-    "constant128": "c70d7cd14b1257a01cc49f8edfcc7685d430e5301e2f2d60ed426936f8b96c51",
-    "projected128": "980161458b9463af09a8e3178063fea0f4bbeb465329e1d3becdb0f224537b54",
-}
-ROLES = ("uniform_root", "uniform_fine", "constant", "projected_linear")
-
-SHARED = ("complete_matrix", "no_extra_cases", "no_duplicate_cases", "finite_receipts",
-          "same_source_and_harness", "clean_a135252_numerical_source",
-          "same_recorded_runtime", "same_explicit_device", "same_early_sampling")
-PER_CASE = ("complete_times", "scales", "actual_builds", "reference", "runtime_source",
-            "patch", "workload")
-
-
-METADATA_ULPS = 4
-
-
-def close_ulps(recorded, expected, ulps=METADATA_ULPS):
-    """Portable check for recomputed float metadata only (e.g. eps = |k|^2).
-
-    The recorded value comes from another runtime/libm, so exact equality can
-    fail by one ULP (observed: 0.012047856934923534 Horsea vs ...532 here).
-    A few ULPs is far below any meaningful change; hashes, case identity and
-    scientific thresholds stay exact.
-    """
-    return (isinstance(recorded, float) and math.isfinite(recorded)
-            and abs(recorded - expected) <= ulps * math.ulp(max(abs(recorded), abs(expected))))
-
-
-def metadata_ok(record, n):
-    return (record.get("flow") == "shear_wave" and record.get("mode") == list(sw.MODE)
-            and record.get("polarization") == sw.E.tolist()
-            and record.get("angle_deg") == sw.ANGLE_DEG and record.get("phase") == sw.PHI
-            and close_ulps(record.get("eps"), sw.eps(n))
-            and record.get("numerics") == tg.NUMERICS
-            and record.get("initialization") == sw.INITIALIZATION
-            and record.get("limits") == sw.LIMITS
-            and record.get("early_pressure") == dict(enabled=False, rows=[],
-                                                     sampled_max_pressure_l2=None)
-            and (record.get("source") or {}).get("shear_wave_sha256") == SHEAR_WAVE_SHA256)
-
-
-def cases_for(scaled):
-    factor = 2 if scaled else 1
-    return tuple((re, n * factor, depth, scheme) for re, n, depth, scheme in tg.CASES)
-
-
-def assess(records, expected_revision=None, *, scaled=False):
-    if not isinstance(records, list) or not all(isinstance(r, dict) for r in records):
-        raise ValueError("records must be a list of receipt objects")
-    # The scaled TG assessor supplies N256/512 cases, builds and workload; its
-    # TG-only diagnostic identity and early-sampling checks are not used here.
-    base_checks = tg.assess(records, expected_revision,
-                            diagnostic=SCALED_DIAGNOSTIC if scaled else None)["checks"]
-    checks = {name: base_checks.get(name, False) for name in SHARED}
-    checks["shear_diagnostic_identity"] = all(
-        r.get("diagnostic") == (SCALED_SHEAR if scaled else None) for r in records)
-    cases = cases_for(scaled)
-    indexed = {}
-    for r in records:
-        indexed.setdefault(tuple(r.get(k) for k in ("re_L", "n", "depth", "explosion")), r)
-    for key in cases:
-        _, n, depth, scheme = key
-        label = f"{n}/{depth}/{scheme}"
-        for name in PER_CASE:
-            checks[f"{label} {name}"] = base_checks.get(f"{label} {name}", False)
-        checks[f"{label} shear_metadata"] = key in indexed and metadata_ok(indexed[key], n)
-    contract_valid = all(checks.values())
-    result = dict(checks=checks, contract_valid=contract_valid,
-                  cases=[list(k) for k in cases], expected_revision=expected_revision,
-                  diagnostic=SCALED_SHEAR if scaled else None,
-                  scope="2D periodic Re100 oblique (2,1) shear wave; one phase and one "
-                        "rectangle; no placement robustness or convergence order")
-    if not contract_valid:
-        result.update(status="INVALID_SET", passed=False)
-        return result
-    try:
-        physics = sw.assess(indexed[cases[0]], indexed[cases[1]],
-                            [indexed[cases[2]], indexed[cases[3]]])
-    except (KeyError, ValueError) as error:
-        result.update(status="INVALID_SET", passed=False, reason=str(error))
-        return result
-    result.update(physics=physics, status=physics["status"],
-                  passed=physics["status"] == "PASS")
-    try:
-        result["signed"] = signed_summary([indexed[k] for k in cases])
-    except (KeyError, TypeError, ValueError) as error:
-        result["signed_unavailable"] = str(error)
-    return result
-
-
-CASE_AGNOSTIC = ("finite_receipts", "same_source_and_harness", "clean_a135252_numerical_source",
-                 "same_recorded_runtime", "same_explicit_device", "same_early_sampling")
-
-
-# Fixed multi-box presets sharing one contract; only geometry, controls, pins differ.
-PRESETS = {
-    NESTED_SHEAR: dict(
-        module=nested, physics=nested.assess, snapshot=True,
-        pins={"shear_nested_sha256": SHEAR_NESTED_SHA256},
-        finest_control="uniform 4N (U512)",
-        scope="2D periodic Re100 oblique (2,1) shear wave; fixed three-level/two-region "
-              "placement; changes placement and refined volume as well as depth, so no "
-              "isolated-level cost or resolution trend"),
-    TWIN_SHEAR: dict(
-        module=twin, physics=sw.assess, snapshot=False,
-        pins={"shear_nested_sha256": SHEAR_NESTED_SHA256,
-              "shear_twin_sha256": SHEAR_TWIN_SHA256},
-        finest_control="uniform 2N (U256)",
-        scope="2D periodic Re100 oblique (2,1) shear wave; depth-2 twin of the nested "
-              "preset (same two L0->L1 boxes, no L2). Twin vs nested is the effect of adding "
-              "this nested refinement; it also changes finest spacing and refined volume, so it "
-              "does not isolate abstract depth"),
-}
-
-
-def _nested_case_ok(r, n, depth, diagnostic=NESTED_SHEAR):
-    """Per-case identity of a fixed multi-box preset (scales, builds, patch, work, pins)."""
-    preset = PRESETS[diagnostic]
-    geometry = preset["module"]
-    runtime = r.get("runtime_source", {})
-    package = Path(runtime.get("checkout", "")) / "src/CelerisLab"
-    cells = [n * n] if depth == 1 else geometry.LEAVES
-    hops = [16 * n * 2**level for level in range(depth)]
-    work = r.get("workload", {})
-    snapshot = r.get("final_snapshot")
-    expected_patch = [] if depth == 1 else geometry.REFINEMENTS
-    return {
-        "complete_times": r.get("completed") is True and tg.at_steps(
-            r.get("rows", []), sample_steps(n)[0], n),
-        "scales": (r.get("U") == sw.U and tg.finite(r.get("viscosity"))
-                   and abs(r["viscosity"] - sw.U * n / 100) < 1e-15
-                   and r.get("tau_by_level") == [0.5 + 3 * sw.U * n / 100 * 2**l
-                                                 for l in range(depth)]
-                   and r.get("mach") == sw.U * math.sqrt(3)),
-        "actual_builds": tg.valid_builds(r, n, depth),
-        "reference": (r.get("numerical_revision") == tg.NUMERICAL_REVISION
-                      and r.get("reference_harness") == tg.REFERENCE_HARNESS),
-        "runtime_source": bool(runtime.get("checkout")) and all(
-            runtime.get(k) == str(package / tail) for k, tail in
-            (("module", "__init__.py"), ("compiler", "cuda/compiler_v2.py"),
-             ("kernel_root", "lbm/kernels"))),
-        "patch": json.dumps(r.get("refinements")) == json.dumps(expected_patch),
-        "workload": (work.get("active_cells_by_level") == cells and work.get("level_hops") == hops
-                     and work.get("root_intervals") == 16 * n
-                     and work.get("active_collision_updates_by_level") == [
-                         c * h for c, h in zip(cells, hops)]
-                     and work.get("active_collision_updates") == sum(
-                         c * h for c, h in zip(cells, hops))),
-        "shear_metadata": metadata_ok(r, n),
-        "nested_module_pin": all((r.get("source") or {}).get(key) == pin
-                                 for key, pin in preset["pins"].items()),
-        # Optional, nested projected depth-3 only; bounded and hashed when present.
-        "snapshot": snapshot is None or (
-            preset["snapshot"] and depth == nested.DEPTH and r.get("explosion") == "projected_linear"
-            and snapshot.get("kept") is True and isinstance(snapshot.get("sha256"), str)
-            and len(snapshot["sha256"]) == 64
-            and 0 < snapshot.get("bytes", 0) <= nested.SNAPSHOT_MAX_BYTES
-            and snapshot.get("leaf_counts") == nested.LEAVES
-            and snapshot.get("step") == sample_steps(n)[0][-1]),
-    }
-
-
-def assess_nested(records, expected_revision=None, diagnostic=NESTED_SHEAR):
-    """Fixed four-case preset contract: nested_shear_n128 (U128, U512, constant/projected
-    R128 depth 3) or twin_shear_n128 (U128, U256, constant/projected R128 depth 2)."""
-    preset = PRESETS[diagnostic]
-    geometry = preset["module"]
-    if not isinstance(records, list) or not all(isinstance(r, dict) for r in records):
-        raise ValueError("records must be a list of receipt objects")
-    base_checks = tg.assess(records, expected_revision)["checks"]
-    checks = {name: base_checks.get(name, False) for name in CASE_AGNOSTIC}
-    indexed, duplicates = {}, []
-    for r in records:
-        key = tuple(r.get(k) for k in ("re_L", "n", "depth", "explosion"))
-        (duplicates.append(key) if key in indexed else indexed.__setitem__(key, r))
-    checks.update(complete_matrix=all(k in indexed for k in geometry.CASES),
-                  no_extra_cases=set(indexed) <= set(geometry.CASES),
-                  no_duplicate_cases=not duplicates,
-                  shear_diagnostic_identity=all(r.get("diagnostic") == diagnostic
-                                                for r in records))
-    for key in geometry.CASES:
-        _, n, depth, scheme = key
-        label = f"{n}/{depth}/{scheme}"
-        case = _nested_case_ok(indexed[key], n, depth, diagnostic) if key in indexed else {}
-        for name in ("complete_times", "scales", "actual_builds", "reference", "runtime_source",
-                     "patch", "workload", "shear_metadata", "nested_module_pin", "snapshot"):
-            checks[f"{label} {name}"] = bool(case.get(name, False))
-    contract_valid = all(checks.values())
-    result = dict(checks=checks, contract_valid=contract_valid, diagnostic=diagnostic,
-                  cases=[list(k) for k in geometry.CASES], expected_revision=expected_revision,
-                  finest_control=preset["finest_control"], scope=preset["scope"])
-    if not contract_valid:
-        result.update(status="INVALID_SET", passed=False)
-        return result
-    try:
-        cases = geometry.CASES
-        physics = preset["physics"](indexed[cases[0]], indexed[cases[1]],
-                                    [indexed[cases[2]], indexed[cases[3]]])
-    except (KeyError, ValueError) as error:
-        result.update(status="INVALID_SET", passed=False, reason=str(error))
-        return result
-    result.update(physics=physics, status=physics["status"], passed=physics["status"] == "PASS")
-    try:
-        # Role "uniform_fine" is the preset's finest control (4N nested, 2N twin).
-        result["signed"] = signed_summary([indexed[k] for k in geometry.CASES])
-    except (KeyError, TypeError, ValueError) as error:
-        result["signed_unavailable"] = str(error)
-    return result
-
-
-def _signed(record):
-    """Raw signed quantities of one valid record (None when the fit is unavailable)."""
-    s = sw.summarize(record)
-    bias = None if not s["rate_fit_valid"] else s["rate"] / s["exact_rate"] - 1
-    return dict(n=record["n"], depth=record["depth"], explosion=record["explosion"],
-                rate_fit_valid=s["rate_fit_valid"], signed_rate_bias=bias,
-                rate_tstar=s["rate_tstar"], exact_rate_tstar=s["exact_rate_tstar"],
-                interval_rate_errors=s["interval_rate_errors"],
-                residual_l2=s["residual_l2"], spurious_pressure_scaled=s["spurious_pressure_scaled"],
-                spurious_pressure_rms=s["spurious_pressure_rms"],
-                final_amplitude_error=record["rows"][-1]["amplitude_error"])
-
-
-def signed_summary(records):
-    """Signed bias per case and refined excess over each uniform control."""
-    rows = dict(zip(ROLES, (_signed(r) for r in records)))
-
-    def minus(a, b):
-        return None if a is None or b is None else a - b
-
-    for role in ("constant", "projected_linear"):
-        for control in ("uniform_root", "uniform_fine"):
-            rows[role][f"excess_over_{control}"] = {
-                key: minus(rows[role][key], rows[control][key])
-                for key in ("signed_rate_bias", "residual_l2", "spurious_pressure_rms")}
-    return rows
-
-
-def load_reference(paths):
-    """The four audited N128 receipts verbatim; never relabelled as fresh controls."""
-    blobs = [Path(path).read_bytes() for path in paths]
-    hashes = {hashlib.sha256(blob).hexdigest() for blob in blobs}
-    if len(blobs) != 4 or hashes != set(REFERENCE_RECEIPTS.values()):
-        raise ValueError("N128 receipt hashes differ from the audited de5b0cc evidence")
-    return [json.loads(blob) for blob in blobs]
-
-
-def resolution_trend(new_result, reference, reference_revision=REFERENCE_REVISION):
-    """Descriptive N128 -> N256 signed changes; never an acceptance gate or an order."""
-    old_result = assess(reference, reference_revision)
-    if "signed" not in old_result or "signed" not in new_result:
-        return dict(valid=False, reason="N128 reference or N256 set lacks a valid signed summary")
-    out = {}
-    for role in ROLES:
-        old, new = old_result["signed"][role], new_result["signed"][role]
-        out[role] = {}
-        for key in ("signed_rate_bias", "residual_l2", "spurious_pressure_rms",
-                    *(f"excess_over_{c}" for c in ("uniform_root", "uniform_fine"))):
-            if key not in old:
-                continue
-            pairs = old[key].items() if isinstance(old[key], dict) else [(None, old[key])]
-            for sub, low in pairs:
-                high = new[key][sub] if sub else new[key]
-                ok = low is not None and high is not None
-                out[role][key if sub is None else f"{key}.{sub}"] = dict(
-                    n128=low, n256=high, signed_change=high - low if ok else None,
-                    n256_to_n128=high / low if ok and low else None)
-    return dict(valid=True, reference_revision=reference_revision,
-                reference_receipt_sha256=REFERENCE_RECEIPTS,
-                reference_status=old_result["status"], changes=out,
-                scope="same-placement two-resolution trend; not a convergence order, "
-                      "placement robustness or redesign decision")
-
-
-if __name__ == "__main__":
-    p = argparse.ArgumentParser(description=__doc__)
-    p.add_argument("files", type=Path, nargs=4)
-    p.add_argument("--output", type=Path, required=True)
-    p.add_argument("--expected-revision", required=True)
-    p.add_argument("--diagnostic", choices=[SCALED_SHEAR, NESTED_SHEAR, TWIN_SHEAR])
-    p.add_argument("--reference-files", type=Path, nargs=4)
-    args = p.parse_args()
-    if args.output.exists():
-        p.error("Output already exists; choose a new path to retain prior evidence")
-    if args.diagnostic in PRESETS:
-        if args.reference_files:
-            p.error(f"{args.diagnostic} takes no reference files (no resolution trend)")
-        result = assess_nested([json.loads(path.read_text()) for path in args.files],
-                               args.expected_revision, args.diagnostic)
-        text = json.dumps(result, indent=2, allow_nan=False) + "\n"
-        args.output.write_text(text)
-        print(text, end="")
-        raise SystemExit(0 if result["passed"] else 1)
-    if bool(args.diagnostic) != bool(args.reference_files):
-        p.error("--diagnostic scaled_shear_n256 requires --reference-files (N128 receipts)")
-    result = assess([json.loads(path.read_text()) for path in args.files], args.expected_revision,
-                    scaled=bool(args.diagnostic))
-    if args.diagnostic:
-        try:
-            reference = load_reference(args.reference_files)
-        except ValueError as exc:
-            p.error(str(exc))
-        result["resolution_trend"] = resolution_trend(result, reference)
-    text = json.dumps(result, indent=2, allow_nan=False) + "\n"
-    args.output.write_text(text)
-    print(text, end="")
-    raise SystemExit(0 if result["passed"] else 1)

tests/validation/taylor_green/run_case.py

@@ -18,37 +18,6 @@ SOURCE_SHA256 = "a5dbfd804befce868067d79a23e5fd47dce7f505b3f9b1bb2145fb57cb5f217
 BUILD_CAPTURE_SHA256 = "3dbaa6547cb0a4cb1541054f3b64ad8b6e18cc70527ac6166e56b944e9bd464a"
 REFERENCE_HARNESS = "11901a7f77557a901e017a171eeae1758d584fa5"
 INITIALIZATION = "physical FP64 equilibrium G at actual cell centers; rho=1+3p"
-SHEAR_WAVE_SHA256 = "81d5c8ee60864372887cddf9239580c82fb6750d956038f1e3ee9de61aa4e877"
-SCALED_DIAGNOSTIC = "scaled_n256"
-SCALED_SHEAR = "scaled_shear_n256"  # mutually exclusive with scaled_n256 (one flow each)
-NESTED_SHEAR = "nested_shear_n128"  # fixed three-level/two-region shear preset
-SHEAR_NESTED_SHA256 = "fa6cfe87fb4df8c6d732c637c885276833c81973b950c7724d734f8fc350bcb0"
-TWIN_SHEAR = "twin_shear_n128"  # depth-2 twin: nested L0->L1 boxes without L2
-SHEAR_TWIN_SHA256 = "1cbf37f18e89aea577581631c4565f51e68d22a3739b698816ef64acbf2b2bb4"
-SHEAR_PROBES_SHA256 = "53ba8af8ac9c8078c40f84488c7ade4c11ccc91dd1fc275ff806042e9af30166"  # signed interface-probe mechanism diagnostic
-
-
-def flow_functions(flow="taylor_green"):
-    """(initial, metrics, limits, initialization); the default is the frozen TG oracle."""
-    if flow == "taylor_green":
-        return initial, metrics, LIMITS, INITIALIZATION
-    if flow == "shear_wave":
-        import shear_wave
-        return shear_wave.initial, shear_wave.metrics, shear_wave.LIMITS, shear_wave.INITIALIZATION
-    raise ValueError(f"unknown flow {flow!r}")
-
-
-def finite_row(row):
-    """Every scalar or list-valued diagnostic is finite (TG rows are all scalars)."""
-    return all(np.isfinite(np.asarray(value, dtype=float)).all() for value in row.values())
-
-
-def sample(run, masks, step, n, viscosity, initial_mass, metrics, depth, label="sample"):
-    arrays = (run.download(),) if depth == 1 else run.download()
-    row = metrics(arrays, masks, step, n, viscosity, initial_mass)
-    if not finite_row(row):
-        raise FloatingPointError(f"nonfinite {label} diagnostics")
-    return row
 
 
 def sample_steps(n, early_pressure=False):
@@ -95,7 +64,7 @@ def provenance(repo):
     )
 
 
-def verify_source(repo, revision, flow="taylor_green", probes=False):
+def verify_source(repo, revision):
     """Exact clean harness commit, fixed production tree, and reviewed capture helper."""
     import oracle
     from tests.validation.multigrid import check_projected_pairs as gate
@@ -114,34 +83,6 @@ def verify_source(repo, revision, flow="taylor_green", probes=False):
     if result["source_tree_sha256"] != SOURCE_SHA256:
         raise RuntimeError("Wrong numerical source fingerprint")
     result["build_capture_sha256"] = BUILD_CAPTURE_SHA256
-    if probes:
-        import shear_probes
-        module = harness / "shear_probes.py"
-        if (Path(shear_probes.__file__).resolve() != module
-                or hashlib.sha256(module.read_bytes()).hexdigest() != SHEAR_PROBES_SHA256):
-            raise RuntimeError("Wrong shear_probes module checkout or content")
-        result["shear_probes_sha256"] = SHEAR_PROBES_SHA256
-    if flow == "shear_twin":
-        import shear_twin
-        module = harness / "shear_twin.py"
-        if (Path(shear_twin.__file__).resolve() != module
-                or hashlib.sha256(module.read_bytes()).hexdigest() != SHEAR_TWIN_SHA256):
-            raise RuntimeError("Wrong shear_twin module checkout or content")
-        result["shear_twin_sha256"] = SHEAR_TWIN_SHA256
-    if flow in ("shear_nested", "shear_twin"):  # the twin reuses the nested geometry
-        import shear_nested
-        module = harness / "shear_nested.py"
-        if (Path(shear_nested.__file__).resolve() != module
-                or hashlib.sha256(module.read_bytes()).hexdigest() != SHEAR_NESTED_SHA256):
-            raise RuntimeError("Wrong shear_nested module checkout or content")
-        result["shear_nested_sha256"] = SHEAR_NESTED_SHA256
-    if flow in ("shear_wave", "shear_nested", "shear_twin"):
-        import shear_wave
-        module = harness / "shear_wave.py"
-        if (Path(shear_wave.__file__).resolve() != module
-                or hashlib.sha256(module.read_bytes()).hexdigest() != SHEAR_WAVE_SHA256):
-            raise RuntimeError("Wrong shear_wave module checkout or content")
-        result["shear_wave_sha256"] = SHEAR_WAVE_SHA256
     return result
 
 
@@ -204,79 +145,26 @@ def main():
     p.add_argument("--run-gpu", action="store_true")
     p.add_argument("--dry-run", action="store_true")
     p.add_argument("--re", type=int, choices=[100, 1000], required=True)
-    p.add_argument("--n", type=int, choices=[32, 64, 128, 256, 512], required=True)
+    p.add_argument("--n", type=int, choices=[32, 64, 128, 256], required=True)
     p.add_argument("--depth", type=int, choices=[1, 2, 3], required=True)
     p.add_argument("--output", type=Path, required=True)
     p.add_argument("--explosion", choices=["constant", "projected_linear"], default="constant")
-    p.add_argument("--diagnostic",
-                   choices=[SCALED_DIAGNOSTIC, SCALED_SHEAR, NESTED_SHEAR, TWIN_SHEAR],
-                   help="explicit four-case N256/fine512 same-placement diagnostic "
-                        "(scaled_n256: Taylor-Green; scaled_shear_n256: shear wave) or the "
-                        "fixed three-level/two-region shear preset (nested_shear_n128) "
-                        "or its depth-2 twin (twin_shear_n128)")
-    p.add_argument("--probe-trace", action="store_true",
-                   help="signed interface-probe trace (nested U128/U512/projected d3, "
-                        "twin projected d2); mechanism diagnostic, no gates")
-    p.add_argument("--final-snapshot", action="store_true",
-                   help="nested_shear_n128 projected depth-3 only: final macro snapshot")
     p.add_argument("--early-pressure", action="store_true",
                    help="also save 65 scalar pressure samples at t*=k*.001875, k=0..64")
-    p.add_argument("--flow", choices=["taylor_green", "shear_wave"], default="taylor_green")
     args = p.parse_args()
-    nested = args.diagnostic == NESTED_SHEAR
-    if args.flow == "shear_wave" and (args.re != 100 or (args.depth == 3 and not nested)
-                                      or args.early_pressure):
-        p.error("shear_wave requires --re 100, depth 1 or 2 and no --early-pressure")
-    probe_cases = {(NESTED_SHEAR, 128, 1, "constant"), (NESTED_SHEAR, 512, 1, "constant"),
-                   (NESTED_SHEAR, 128, 3, "projected_linear"),
-                   (TWIN_SHEAR, 128, 2, "projected_linear")}
-    if args.probe_trace and (args.final_snapshot or (
-            args.diagnostic, args.n, args.depth, args.explosion) not in probe_cases):
-        p.error("--probe-trace requires nested U128/U512/projected depth 3 or twin projected "
-                "depth 2, without --final-snapshot")
-    if args.final_snapshot and not (nested and args.depth == 3
-                                    and args.explosion == "projected_linear"):
-        p.error("--final-snapshot requires nested_shear_n128 projected depth 3")
-    initial, metrics, limits, initialization = flow_functions(args.flow)
     if args.output.exists():
         p.error("Output already exists; choose a new path to retain prior evidence")
-    if args.explosion != "constant" and args.depth != 2 and not nested:
+    if args.explosion != "constant" and args.depth != 2:
         p.error("projected_linear requires depth 2")
-    twin = args.diagnostic == TWIN_SHEAR
-    if nested or twin:
-        import shear_nested
-        import shear_twin
-        preset = shear_nested if nested else shear_twin
-        if args.flow != "shear_wave":
-            p.error(f"--diagnostic {args.diagnostic} requires --flow shear_wave")
-        if (args.re, args.n, args.depth, args.explosion) not in preset.CASES:
-            p.error(f"{args.diagnostic} requires one of its four Re100 cases")
-    elif args.diagnostic:
-        cases = {(256, 1, "constant"), (512, 1, "constant"),
-                 (256, 2, "constant"), (256, 2, "projected_linear")}
-        flow = "shear_wave" if args.diagnostic == SCALED_SHEAR else "taylor_green"
-        if args.flow != flow:
-            p.error(f"--diagnostic {args.diagnostic} requires --flow {flow}")
-        if args.diagnostic == SCALED_DIAGNOSTIC and (
-                args.re != 100 or (args.n, args.depth, args.explosion) not in cases
-                or not args.early_pressure):
-            p.error("scaled_n256 requires one of its four Re100 cases and --early-pressure")
-        if args.diagnostic == SCALED_SHEAR and (args.n, args.depth, args.explosion) not in cases:
-            p.error("scaled_shear_n256 requires one of its four Re100 cases")
-    elif args.n == 512:
-        p.error("N512 requires --diagnostic scaled_n256, scaled_shear_n256 or nested_shear_n128")
     selected = os.environ.get("CUDA_VISIBLE_DEVICES", "")
     if not args.dry_run and (not args.run_gpu or not selected or "," in selected or selected == "-1"):
         p.error("--run-gpu and exactly one explicit CUDA_VISIBLE_DEVICES are required")
     repo = args.repo.resolve()
     sys.path[:0] = [str(repo / "src"), str(repo)]
-    source = verify_source(repo, args.expected_revision,
-                           "shear_nested" if nested else "shear_twin" if twin else args.flow,
-                           probes=args.probe_trace)
+    source = verify_source(repo, args.expected_revision)
     runtime = runtime_source(repo)
     if args.dry_run:
-        print(json.dumps(dict(source=source, runtime_source=runtime, dry_run=True,
-                              **({"diagnostic": args.diagnostic} if args.diagnostic else {}))))
+        print(json.dumps(dict(source=source, runtime_source=runtime, dry_run=True)))
         return 0
     from CelerisLab.cuda.context import CudaContext
     from CelerisLab.lbm.blocks import BlockLayout2D
@@ -286,12 +174,7 @@ def main():
     from CelerisLab.lbm.hierarchy import build_hierarchy, leaf_partition
 
     cfg = config(args.n, args.re)
-    if args.depth == 1:
-        refinements = []
-    elif nested or twin:
-        refinements = [list(level) for level in preset.REFINEMENTS]
-    else:
-        refinements = rectangles(args.n, args.depth)
+    refinements = [] if args.depth == 1 else rectangles(args.n, args.depth)
     h = build_hierarchy(cfg, refinements)
     np.testing.assert_array_equal(leaf_partition(h), np.ones((args.n, args.n)))
     masks = [k == ACTIVE for k in h.kinds]
@@ -314,7 +197,7 @@ def main():
         mach=U * np.sqrt(3),
         viscosity=cfg.viscosity,
         tau_by_level=[0.5 + 3 * c.viscosity for c in h.configs],
-        initialization=initialization,
+        initialization=INITIALIZATION,
         numerics=dict(lattice_model=cfg.lattice_model, collision=cfg.collision,
                       store_precision=cfg.store_precision, ddf_shifting=cfg.ddf_shifting,
                       streaming=cfg.streaming, les_enabled=cfg.les_enabled,
@@ -322,20 +205,13 @@ def main():
                       sample_phase="postcollision G at root synchronization"),
         cuda_visible_devices=selected,
         device_id=0,
-        limits=limits,
+        limits=LIMITS,
         workload=workload(masks, round(TIMES[-1] * args.n / U)),
         rows=[],
         early_pressure=dict(enabled=args.early_pressure, rows=[],
                             sampled_max_pressure_l2=None),
         completed=False,
     )
-    if args.flow != "taylor_green":
-        import shear_wave
-        report.update(flow=args.flow, mode=list(shear_wave.MODE),
-                      polarization=shear_wave.E.tolist(), angle_deg=shear_wave.ANGLE_DEG,
-                      phase=shear_wave.PHI, eps=shear_wave.eps(args.n))
-    if args.diagnostic:
-        report["diagnostic"] = args.diagnostic
     args.output.parent.mkdir(parents=True, exist_ok=True)
     def save():
         temporary = args.output.with_suffix(args.output.suffix + ".tmp")
@@ -370,37 +246,17 @@ def main():
                 ]
             )
             initial_mass = None
-            probe_steps = set()
-            if args.probe_trace:
-                import shear_probes
-                probe_root = dict(zip(shear_probes.case_steps(args.n), shear_probes.STEPS))
-                probe_steps = set(probe_root)
-                probes = shear_probes.select(masks, args.n)
-                report["probe_trace"] = shear_probes.new_trace(
-                    probes, cfg.viscosity, [args.diagnostic, args.n, args.depth, args.explosion])
-            for step in sorted(set(main_steps + early_steps) | probe_steps):
+            for step in sorted(set(main_steps + early_steps)):
                 run.step(step - run.step_count)
-                if step in probe_steps:
-                    trace = report["probe_trace"]
-                    trace["steps"].append(probe_root[step])  # root-physical step
-                    trace["values"].append(shear_probes.sample(
-                        (run.download(),) if args.depth == 1 else run.download(), probes))
-                    if step not in main_steps and step not in early_steps:
-                        continue  # probe-only step: no qualification metrics
-                row = sample(run, masks, step, args.n, cfg.viscosity, initial_mass,
-                             metrics, args.depth)
+                arrays = (run.download(),) if args.depth == 1 else run.download()
+                row = metrics(arrays, masks, step, args.n, cfg.viscosity, initial_mass)
+                if not all(np.isfinite(value) for value in row.values()):
+                    raise FloatingPointError("nonfinite sample diagnostics")
                 row["step"] = step
                 if initial_mass is None:
                     initial_mass = row["mass"]
                 if step in main_steps:
                     report["rows"].append(row)
-                if args.final_snapshot and step == main_steps[-1]:
-                    # Optional macro-only snapshot; scalar receipt stays authoritative.
-                    report["final_snapshot"] = shear_nested.write_snapshot(
-                        args.output.with_name(args.output.stem + ".final_macro.npz"),
-                        run.download(), masks,
-                        shear_nested.snapshot_meta(step, cfg.viscosity, args.explosion,
-                                                   source.get("revision")))
                 if step in early_steps:
                     trace = report["early_pressure"]
                     trace["rows"].append({key: row[key] for key in ("step", "tstar", "pressure_l2")})
@@ -422,8 +278,10 @@ def main():
                     # Exercise real kernels/halos/transfers on every level before READY.
                     # This is the first measured trajectory step, not discarded warmup.
                     run.step(1)
-                    sample(run, masks, 1, args.n, cfg.viscosity, initial_mass,
-                           metrics, args.depth, "READY")
+                    probe = (run.download(),) if args.depth == 1 else run.download()
+                    probe_metrics = metrics(probe, masks, 1, args.n, cfg.viscosity, initial_mass)
+                    if not all(np.isfinite(value) for value in probe_metrics.values()):
+                        raise FloatingPointError("nonfinite READY diagnostics")
                     report["ready_after_step"] = 1
                     save()
                     print(
@@ -439,16 +297,11 @@ def main():
                         ),
                         flush=True,
                     )
-    if args.probe_trace:
-        try:
-            report["probe_trace"]["bytes"] = shear_probes.validate(report["probe_trace"])
-        except ValueError as error:  # keep the scalar receipt; drop an invalid trace
-            report["probe_trace"] = dict(error=str(error))
     report.update(
         completed=True,
         seconds=time.monotonic() - started,
         screening_pass=all(
-            row[key] <= limit for row in report["rows"] for key, limit in limits.items()
+            row[key] <= limit for row in report["rows"] for key, limit in LIMITS.items()
         ),
     )
     save()

tests/validation/taylor_green/shear_nested.py

@@ -1,174 +0,0 @@
-"""Fixed three-level/two-region shear preset (opt-in nested_shear_n128).
-
-Four fresh cases: U128, U512 (finest control = 4N), constant R128 depth 3,
-projected R128 depth 3. Same wave, phase, Re100/U=0.03, initialization, five
-sample times, eps(root N), limits and floors as shear_wave. This changes
-placement and refined volume as well as depth: no isolated-level cost or
-resolution-trend label. shear_wave.py is reused unchanged (historical receipt
-identities stay valid); only the depth/finest-control contract is generalized
-here.
-"""
-
-import hashlib
-import json
-from pathlib import Path
-
-import numpy as np
-
-import shear_wave as sw
-from oracle import CX, CY, U, centers
-
-ROOT_N = 128
-DEPTH = 3
-FINEST_FACTOR = 2 ** (DEPTH - 1)  # finest-spacing uniform control is 4N
-# Parent-frame (x0, y0, x1, y1) rectangles; level-wide, zero-origin unions.
-REFINEMENTS = [
-    [(16, 16, 60, 112), (68, 24, 112, 120)],     # L0 -> L1, root coordinates
-    [(44, 44, 108, 212), (148, 60, 212, 228)],   # L1 -> L2, L1 coordinates
-]
-CASES = ((100, ROOT_N, 1, "constant"), (100, FINEST_FACTOR * ROOT_N, 1, "constant"),
-         (100, ROOT_N, DEPTH, "constant"), (100, ROOT_N, DEPTH, "projected_linear"))
-ROOT_STEPS = 16 * ROOT_N
-LEAVES = [7936, 12288, 86016]
-HOPS = [ROOT_STEPS * 2**level for level in range(DEPTH)]  # [2048, 4096, 8192]
-WORK = sum(c * h for c, h in zip(LEAVES, HOPS))           # 771227648 per refined case
-NU = [U * ROOT_N / sw.RE * 2**level for level in range(DEPTH)]  # [.0384, .0768, .1536]
-TAU = [0.5 + 3 * nu for nu in NU]                                # [.6152, .7304, .9608]
-SNAPSHOT_MAX_BYTES = 8 * 1024 * 1024
-SNAPSHOT_KEYS = ("level", "i", "j", "rho", "ux", "uy", "meta")
-
-
-def leaf_masks():
-    """Independent numpy leaf masks of the fixed preset (root, L1, L2 level-wide grids)."""
-    masks, covered = [], None
-    for level in range(DEPTH):
-        size = ROOT_N * 2**level
-        inside = np.ones((size, size), bool) if level == 0 else covered
-        if level < DEPTH - 1:
-            child = np.zeros((size, size), bool)
-            for x0, y0, x1, y1 in REFINEMENTS[level]:
-                child[y0:y1, x0:x1] = True
-            masks.append(inside & ~child)
-            covered = np.kron(child, np.ones((2, 2), bool))
-        else:
-            masks.append(inside)
-    return masks
-
-
-def assess(base_control, finest_control, refined):
-    """shear_wave.assess generalized to depth 3 with a 4N finest control.
-
-    Same summaries, screens, budgets and outcome semantics; only the
-    (depth, finest-control) shape contract differs.
-    """
-    if base_control is None or finest_control is None or not refined:
-        return dict(status="INVALID_CONTROL", reason="missing control or refined run")
-    n = base_control["n"]
-    if (base_control["depth"], finest_control["depth"], finest_control["n"]) != (
-            1, 1, FINEST_FACTOR * n):
-        raise ValueError("controls must be uniform N and uniform 4N")
-    if any(r["depth"] != DEPTH or r["n"] != n for r in refined):
-        raise ValueError("refined runs must be depth 3 at root N")
-    if len({r.get("explosion") for r in refined}) != len(refined):
-        raise ValueError("duplicate refined explosion scheme")
-    sources = {repr(r.get("source")) for r in [base_control, finest_control, *refined]}
-    base, fine = sw._usable(base_control), sw._usable(finest_control)
-    if base is None or fine is None or len(sources) != 1:
-        return dict(status="INVALID_CONTROL", reason="incomplete/invalid control or mixed source")
-    controls_pass = base["own_screens_pass"] and fine["own_screens_pass"]
-    report = dict(base_control=base, finest_control=fine, refined={},
-                  controls_pass=controls_pass)
-    statuses = []
-    for r in refined:
-        try:
-            s = sw.summarize(r)
-        except (KeyError, TypeError, ValueError) as error:
-            report["refined"][r["explosion"]] = dict(valid=False, reason=str(error))
-            statuses.append("INVALID_RUN")
-            continue
-        s["valid"] = True
-        s["budget"] = {
-            key: (None if base[key] is None else max(sw.BASELINE_FACTOR * base[key], floor))
-            for key, floor in sw.FLOORS.items()
-        }
-        s["budget_pass"] = all(
-            s[key] is not None and s["budget"][key] is not None and s[key] <= s["budget"][key]
-            for key in sw.FLOORS)
-        s["control_ratios"] = {
-            name: {key: (s[key] / c[key] if s[key] is not None and c[key] else None)
-                   for key in (*sw.FLOORS, "spurious_pressure_rms")}
-            for name, c in (("root", base), ("finest", fine))
-        }
-        s["controlled_pass"] = controls_pass and s["own_screens_pass"] and s["budget_pass"]
-        report["refined"][r["explosion"]] = s
-        statuses.append("PASS" if s["controlled_pass"] else "FAIL")
-    if "INVALID_RUN" in statuses:
-        report["status"] = "INVALID_RUN"
-    elif not controls_pass:
-        report["status"] = "CONTROL_SCREEN_FAIL"
-    else:
-        report["status"] = "PASS" if all(v == "PASS" for v in statuses) else "FAIL"
-    return report
-
-
-def write_snapshot(path, arrays, masks, meta):
-    """Final macro snapshot: packed ACTIVE leaves (level, i, j), rho, ux, uy only.
-
-    No populations, no restart state, no time series. Returns the receipt block;
-    a file over SNAPSHOT_MAX_BYTES is removed and reported, never kept.
-    """
-    path = Path(path)
-    if path.exists():
-        raise FileExistsError(path)
-    cols = {k: [] for k in ("level", "i", "j", "rho", "ux", "uy")}
-    counts = []
-    for level, (g, mask) in enumerate(zip(arrays, masks)):
-        if g.shape != (9, *mask.shape):
-            raise ValueError("population/mask shape mismatch")
-        values = g[:, mask].astype(float)
-        rho = values.sum(axis=0)
-        j, i = np.nonzero(mask)  # row = y index, column = x index
-        cols["level"].append(np.full(rho.size, level, np.uint8))
-        cols["i"].append(i.astype(np.uint16))
-        cols["j"].append(j.astype(np.uint16))
-        cols["rho"].append(rho)
-        cols["ux"].append(CX @ values / rho)
-        cols["uy"].append(CY @ values / rho)
-        counts.append(int(rho.size))
-    packed = {k: np.concatenate(v) for k, v in cols.items()}
-    if not all(np.isfinite(packed[k]).all() for k in ("rho", "ux", "uy")):
-        raise FloatingPointError("nonfinite snapshot macros")
-    meta = dict(meta, leaf_counts=counts, cell_center="h*(index+0.5), h=2**-level",
-                fields="rho, ux, uy from FP64 physical populations at ACTIVE leaves")
-    with path.open("xb") as handle:
-        np.savez_compressed(handle, meta=np.array(json.dumps(meta, sort_keys=True)), **packed)
-    size = path.stat().st_size
-    block = dict(file=path.name, bytes=size, leaf_counts=counts, max_bytes=SNAPSHOT_MAX_BYTES,
-                 step=meta.get("step"), tstar=meta.get("tstar"))
-    if size > SNAPSHOT_MAX_BYTES:
-        path.unlink()
-        return dict(block, kept=False, sha256=None, reason="exceeds snapshot byte cap")
-    block.update(kept=True, sha256=hashlib.sha256(path.read_bytes()).hexdigest())
-    return block
-
-
-def read_snapshot(path):
-    """Validate a snapshot: exact keys, no populations, consistent packed arrays."""
-    with np.load(path, allow_pickle=False) as data:
-        if tuple(sorted(data.files)) != tuple(sorted(SNAPSHOT_KEYS)):
-            raise ValueError("unexpected snapshot contents")
-        out = {k: data[k] for k in data.files}
-    meta = json.loads(str(out.pop("meta")))
-    n = len(out["rho"])
-    if any(len(v) != n for v in out.values()) or sum(meta["leaf_counts"]) != n:
-        raise ValueError("inconsistent snapshot arrays")
-    return meta, out
-
-
-def snapshot_meta(step, viscosity, explosion, source_revision):
-    """Exact time/phase/config identity stored inside the snapshot."""
-    return dict(step=step, tstar=step * U / ROOT_N, phase=sw.PHI, mode=list(sw.MODE),
-                polarization=sw.E.tolist(), amplitude=U, re_L=sw.RE, n=ROOT_N, depth=DEPTH,
-                explosion=explosion, viscosity=viscosity, tau_by_level=TAU,
-                refinements=REFINEMENTS, source_revision=source_revision,
-                origin="level-wide zero-origin grids", time="root synchronization, postcollision")

tests/validation/taylor_green/shear_probes.py

@@ -1,123 +0,0 @@
-"""Signed interface-probe traces for the nested/twin shear presets (mechanism diagnostic).
-
-No pass gates. Native-validated 24-target layout through box 1, in root-128
-physical coordinates, crossing L0->L1 and (nested only) L1->L2 away from corners:
-  horizontal line y = 56 across the vertical faces x = 16 and x = 22;
-  vertical line x = 38 across the horizontal faces y = 16 and y = 22;
-  normal coordinates NORMAL_COORDS on both (nested: 3 L0 + 5 L1 + 4 L2 each).
-Each target maps to the nearest ACTIVE leaf center (tie rule: distance, then
-finer level, then smaller j, then smaller i). Grids differ between cases
-(U128, U512, nested, twin), so actual centers, levels and displacements are
-stored and analytic fields are evaluated at the actual centers.
-Samples are POST-collision G at root synchronization only (root-step units);
-no substep content is observed, and grid-scale alternation can alias.
-"""
-
-import math
-
-import numpy as np
-
-import shear_wave as sw
-from oracle import CX, CY, U
-
-ROOT_N = 128
-NORMAL_COORDS = (12.5, 14.5, 15.5, 16.25, 17.25, 19.25, 20.75, 21.75,
-                 22.125, 23.125, 24.125, 26.125)
-TRANSECTS = {"horizontal_y56": dict(axis=0, other=56.0),   # x varies, y fixed
-             "vertical_x38": dict(axis=1, other=38.0)}     # y varies, x fixed
-STEPS = tuple(range(0, 129)) + tuple(range(1920, 2049))  # root steps, both inclusive
-TRACE_MAX_BYTES = 600_000
-
-
-def points():
-    out = []
-    for name, t in TRANSECTS.items():
-        for along in NORMAL_COORDS:
-            xy = (along, t["other"]) if t["axis"] == 0 else (t["other"], along)
-            out.append((name, along, xy))
-    return out
-
-
-def case_steps(n):
-    """Case lattice steps at the fixed root-physical sample times (U512: 4 per root step)."""
-    return [s * (n // ROOT_N) for s in STEPS]
-
-
-def select(masks, n=ROOT_N):
-    """Nearest ACTIVE leaf center for each target (deterministic tie rule).
-
-    Targets and stored centers are in root-physical units (root cell = 1); a case
-    with root N = n has cell size h = ROOT_N / (n * 2**level) there (U512: 0.25).
-    """
-    if n % ROOT_N:
-        raise ValueError("case root N must be a multiple of 128")
-    probes = []
-    for name, along, (x, y) in points():
-        best = None
-        for level, mask in enumerate(masks):
-            h = ROOT_N / (n * 2 ** level)
-            i0, j0 = int(math.floor(x / h)), int(math.floor(y / h))
-            for j in range(j0 - 2, j0 + 3):
-                for i in range(i0 - 2, i0 + 3):
-                    if 0 <= j < mask.shape[0] and 0 <= i < mask.shape[1] and mask[j, i]:
-                        cx, cy = h * (i + 0.5), h * (j + 0.5)
-                        key = (math.hypot(cx - x, cy - y), -level, j, i)
-                        if best is None or key < best[0]:
-                            best = (key, level, i, j, cx, cy)
-        if best is None:
-            raise ValueError(f"no ACTIVE leaf near target {(x, y)}")
-        _, level, i, j, cx, cy = best
-        probes.append(dict(transect=name, normal=along, point=[x, y], level=level, i=i, j=j,
-                           center=[cx, cy], displacement=[cx - x, cy - y]))
-    if len({(p["level"], p["i"], p["j"]) for p in probes}) != len(probes):
-        raise ValueError("probe targets map to duplicate cells")
-    return probes
-
-
-def sample(arrays, probes):
-    """Flat [rho, ux, uy] per probe from FP64 physical populations."""
-    row = []
-    for p in probes:
-        f = np.asarray(arrays[p["level"]][:, p["j"], p["i"]], dtype=float)
-        rho = float(f.sum())
-        row += [rho, float(CX @ f) / rho, float(CY @ f) / rho]
-    return row
-
-
-def new_trace(probes, case_viscosity, case):
-    """Times/coordinates are root-physical (N=128); nu_root = U*128/Re for all cases."""
-    return dict(schema=1, kind="mechanism diagnostic, no pass gates", case=case,
-                time_unit="root step (N=128)", sample_phase="postcollision G at root synchronization",
-                root_n=ROOT_N, viscosity_root=U * ROOT_N / sw.RE, case_viscosity=case_viscosity,
-                mode=list(sw.MODE), phase=sw.PHI,
-                amplitude=U, fields=["rho", "ux", "uy"], probes=probes, steps=[], values=[])
-
-
-def residuals(trace):
-    """Signed (drho, dux, duy) per step and probe, analytic field at each actual center."""
-    out = []
-    for step, row in zip(trace["steps"], trace["values"]):
-        res = []
-        for n, p in enumerate(trace["probes"]):
-            x, y = p["center"]
-            ux, uy, _ = sw.exact(x, y, step, trace["root_n"], trace["viscosity_root"])
-            rho, vx, vy = row[3 * n: 3 * n + 3]
-            res.append((rho - 1.0, vx - float(ux), vy - float(uy)))
-        out.append(res)
-    return out
-
-
-def validate(trace):
-    """Exact schedule, finite values, fixed probe count and byte cap."""
-    import json
-    if trace.get("steps") != list(STEPS) or len(trace["values"]) != len(STEPS):
-        raise ValueError("trace steps differ from the fixed schedule")
-    if len(trace["probes"]) != len(NORMAL_COORDS) * len(TRANSECTS):
-        raise ValueError("unexpected probe count")
-    width = 3 * len(trace["probes"])
-    if any(len(r) != width or not all(math.isfinite(v) for v in r) for r in trace["values"]):
-        raise ValueError("malformed or nonfinite trace row")
-    size = len(json.dumps(trace, allow_nan=False).encode())
-    if size > TRACE_MAX_BYTES:
-        raise ValueError(f"trace exceeds {TRACE_MAX_BYTES} bytes ({size})")
-    return size

tests/validation/taylor_green/shear_twin.py

@@ -1,36 +0,0 @@
-"""Depth-2 twin of the nested shear preset (opt-in twin_shear_n128).
-
-Same two L0->L1 boxes as shear_nested, no L2. Four fresh cases: U128, U256
-(finest control = 2N), constant R128 depth 2, projected R128 depth 2; same
-wave, phase, Re100/U=0.03, initialization, times, eps(root N), limits, floors.
-
-Twin vs nested measures the effect of adding this nested L2 refinement.
-Removing L2 also changes the finest spacing and refined volume, so the
-contrast does not isolate abstract depth. Physics is the unchanged depth-2,
-2N-control shear_wave.assess; shear_nested.py stays byte-identical.
-"""
-
-import numpy as np
-
-import shear_nested as nested
-
-ROOT_N = nested.ROOT_N
-DEPTH = 2
-FINEST_FACTOR = 2
-REFINEMENTS = [nested.REFINEMENTS[0]]  # L0 -> L1 only, root coordinates
-CASES = ((100, ROOT_N, 1, "constant"), (100, FINEST_FACTOR * ROOT_N, 1, "constant"),
-         (100, ROOT_N, DEPTH, "constant"), (100, ROOT_N, DEPTH, "projected_linear"))
-ROOT_STEPS = 16 * ROOT_N
-LEAVES = [7936, 33792]
-HOPS = [ROOT_STEPS * 2**level for level in range(DEPTH)]  # [2048, 4096]
-WORK = sum(c * h for c, h in zip(LEAVES, HOPS))           # 154664960 per refined case
-NU = nested.NU[:DEPTH]
-TAU = nested.TAU[:DEPTH]
-
-
-def leaf_masks():
-    """Independent numpy leaf masks (root complement, full L1 boxes)."""
-    child = np.zeros((ROOT_N, ROOT_N), bool)
-    for x0, y0, x1, y1 in REFINEMENTS[0]:
-        child[y0:y1, x0:x1] = True
-    return [~child, np.kron(child, np.ones((2, 2), bool))]

tests/validation/taylor_green/shear_wave.py

@@ -1,312 +0,0 @@
-"""CPU-only oblique shear-wave reference and composite-leaf diagnostics.
-
-Convention: integer mode MODE=(2,1) on the L x L periodic root domain, so the
-wavevector k = (2*pi/L)*(2,1) points 26.565 deg from +x (mode (1,2) would be
-63.435 deg). Velocity is polarized along E = (-1,2)/sqrt(5), perpendicular to k.
-The frozen Taylor-Green oracle is reused for constants and geometry only.
-"""
-
-import math
-
-import numpy as np
-from oracle import CX, CY, W, U, TIMES, centers
-
-MODE = (2, 1)
-PHI = 0.0
-E = np.array([-MODE[1], MODE[0]], dtype=float) / math.hypot(*MODE)
-ANGLE_DEG = math.degrees(math.atan2(MODE[1], MODE[0]))
-RE = 100  # Re = U L / nu, the same nu as Taylor-Green Re100 at equal N
-FIT_FROM_TSTAR = 0.12  # late-time samples only; reduces startup sensitivity
-INITIALIZATION = (
-    "physical FP64 equilibrium G at actual cell centers; rho=1 (exact p const)"
-)
-# Per-row screens. phase_drift_abs, residual_l2 and the run-level rate screen
-# use eps(n) and are preregistered diagnostic choices, not error bounds.
-LIMITS = dict(velocity_l2=0.05, spurious_pressure_scaled=0.02, mass_relative=1e-5)
-# The comparative pressure budget max(2*control, 0.02) is never below the 0.02
-# absolute ceiling, so it is always redundant; raw control ratios are kept.
-FLOORS = dict(rate_error=0.002, residual_l2=0.002, spurious_pressure_scaled=0.02)
-BASELINE_FACTOR = 2.0
-
-
-def wavevector(length):
-    return 2 * np.pi / length * np.array(MODE, dtype=float)
-
-
-def decay_rate(length, viscosity):
-    """Exact amplitude decay rate per root step: nu |k|^2."""
-    k = wavevector(length)
-    return viscosity * float(k @ k)
-
-
-def eps(n):
-    """(|k| h_root)^2 with h_root = 1: dimensionless, coefficient one."""
-    k = wavevector(n)
-    return float(k @ k)
-
-
-def exact(x, y, t, length, viscosity, amplitude=U):
-    k = wavevector(length)
-    a = amplitude * np.exp(-decay_rate(length, viscosity) * t)
-    s = np.sin(k[0] * x + k[1] * y + PHI)
-    p = np.zeros_like(s)
-    return a * E[0] * s, a * E[1] * s, p  # kinematic pressure, constant
-
-
-def equilibrium(rho, ux, uy):
-    # Same second-order D2Q9 equilibrium as oracle.initial.
-    cu = CX[:, None, None] * ux + CY[:, None, None] * uy
-    return (
-        W[:, None, None]
-        * rho
-        * (1 + 3 * cu + 4.5 * cu * cu - 1.5 * (ux * ux + uy * uy))
-    )
-
-
-def initial(shape, level, length, viscosity):
-    x, y = centers(shape, level)
-    ux, uy, p = exact(x, y, 0.0, length, viscosity)
-    return equilibrium(1 + 3 * p, ux, uy)
-
-
-def _leaves(arrays, masks):
-    accum = []
-    for level, (g, mask) in enumerate(zip(arrays, masks)):
-        if g.shape != (9, *mask.shape):
-            raise ValueError("population/mask shape mismatch")
-        values = g[:, mask].astype(float)
-        if not np.isfinite(values).all():
-            raise FloatingPointError("nonfinite leaf populations")
-        rho = values.sum(axis=0)
-        if (rho <= 0).any():
-            raise FloatingPointError("nonpositive leaf density")
-        x, y = centers(mask.shape, level)
-        area = np.full(rho.size, 0.25**level)
-        lev = np.full(rho.size, level)
-        accum.append((rho, CX @ values / rho, CY @ values / rho, x[mask], y[mask], area, lev))
-    return [np.concatenate(v) for v in zip(*accum)]
-
-
-def metrics(arrays, masks, t, length, viscosity, initial_mass=None):
-    rho, ux, uy, x, y, w, lev = _leaves(arrays, masks)
-    volume = w.sum()
-    if not np.isclose(volume, length**2, rtol=0, atol=1e-10):
-        raise ValueError("leaf partition does not cover domain once")
-    k = wavevector(length)
-    theta = k[0] * x + k[1] * y + PHI
-    s, c = np.sin(theta), np.cos(theta)
-    v = ux * E[0] + uy * E[1]
-    # Weighted least squares on the actual composite quadrature (no
-    # continuous-orthogonality assumption).
-    gram = np.array([[w @ (s * s), w @ (s * c)], [w @ (s * c), w @ (c * c)]])
-    a_hat, b_hat = np.linalg.solve(gram, [w @ (v * s), w @ (v * c)])
-    ex, ey, _ = exact(x, y, t, length, viscosity)
-    exact_norm = w @ (ex * ex + ey * ey)
-    fit = a_hat * s + b_hat * c
-    longitudinal = (ux * k[0] + uy * k[1]) / math.sqrt(k @ k)
-    amplitude = U * math.exp(-decay_rate(length, viscosity) * t)
-    scale = amplitude * amplitude / 4  # continuum reference scale, not the TG norm
-    modal = math.hypot(a_hat, b_hat)
-    p = (rho - 1) / 3
-    p = p - w @ p / volume  # one global gauge
-    mass = float(w @ rho)
-    return dict(
-        tstar=t * U / length,
-        mass=mass,
-        mass_relative=(
-            0.0 if initial_mass is None else abs(mass - initial_mass) / initial_mass
-        ),
-        a_hat=float(a_hat),
-        b_hat=float(b_hat),
-        amplitude_exact=amplitude,
-        amplitude_ratio=float(a_hat / amplitude),
-        modal_amplitude=modal,
-        amplitude_error=modal / amplitude - 1,
-        phase_drift=float(math.atan2(b_hat, a_hat)),
-        phase_drift_abs=abs(float(math.atan2(b_hat, a_hat))),
-        velocity_l2=float(
-            np.sqrt(w @ ((ux - ex) ** 2 + (uy - ey) ** 2) / exact_norm)
-        ),
-        residual_l2=float(
-            np.sqrt(w @ ((ux - fit * E[0]) ** 2 + (uy - fit * E[1]) ** 2) / exact_norm)
-        ),
-        longitudinal_l2=float(np.sqrt(w @ (longitudinal**2) / exact_norm)),
-        spurious_pressure_rms=float(np.sqrt(w @ (p * p) / volume)),
-        spurious_pressure_scaled=float(np.sqrt(w @ (p * p) / volume) / scale),
-        spurious_pressure_max_scaled=float(np.max(np.abs(p)) / scale),
-        spurious_pressure_scaled_by_level=[
-            float(np.sqrt(w[lev == i] @ (p[lev == i] ** 2) / w[lev == i].sum()) / scale)
-            for i in range(len(masks))
-        ],
-        rho_min=float(rho.min()),
-        rho_max=float(rho.max()),
-        max_speed=float(np.max(np.hypot(ux, uy))),
-        leaf_cells=int(len(rho)),
-    )
-
-
-def fit_rate(rows, length, viscosity):
-    """Free-intercept least squares of ln R, R = hypot(a_hat, b_hat), late samples.
-
-    The intercept absorbs only a constant amplitude prefactor once a single
-    exponential dominates; per-interval rates and the fit residual are kept so
-    a lingering transient stays visible. Rates are per root step of the record
-    (uniform 2N uses its own nu and doubled step counts).
-    """
-    late = [r for r in rows if r["tstar"] >= FIT_FROM_TSTAR - 1e-12]
-    amp = np.array([math.hypot(r["a_hat"], r["b_hat"]) for r in late])
-    if len(late) < 3 or not np.isfinite(amp).all():
-        raise ValueError("need >= 3 late samples with finite R")
-    exact_rate = decay_rate(length, viscosity)
-    to_tstar = length / U  # root steps per unit t*
-    if not (amp > 0).all():
-        # Finite modal extinction: a physical failure, not malformed data. No
-        # clipping and no invented rate; fit quantities are unavailable.
-        return dict(rate_fit_valid=False, rate=None, exact_rate=exact_rate,
-                    rate_tstar=None, exact_rate_tstar=exact_rate * to_tstar,
-                    rate_error=None, interval_rate_errors=None, log_fit_residual_max=None)
-    t = np.array([r["step"] for r in late], dtype=float)
-    (slope, intercept) = np.polyfit(t, np.log(amp), 1)
-    residual = np.log(amp) - (slope * t + intercept)
-    return dict(
-        rate_fit_valid=True, rate=float(-slope), exact_rate=exact_rate,
-        rate_tstar=float(-slope * to_tstar),
-        exact_rate_tstar=exact_rate * to_tstar,  # = 5 (2 pi)^2 / Re
-        rate_error=abs(-slope / exact_rate - 1),
-        interval_rate_errors=[
-            float(-np.log(amp[i + 1] / amp[i]) / (t[i + 1] - t[i]) / exact_rate - 1)
-            for i in range(len(t) - 1)
-        ],
-        log_fit_residual_max=float(np.max(np.abs(residual))),
-    )
-
-
-NONNEGATIVE = ("tstar", "mass", "mass_relative", "amplitude_exact", "modal_amplitude",
-               "phase_drift_abs", "velocity_l2", "residual_l2", "longitudinal_l2",
-               "spurious_pressure_rms", "spurious_pressure_scaled",
-               "spurious_pressure_max_scaled", "rho_min", "rho_max", "max_speed")
-SIGNED = ("a_hat", "b_hat", "amplitude_ratio", "amplitude_error", "phase_drift")
-
-
-def _number(value):
-    return (isinstance(value, (int, float)) and not isinstance(value, bool)
-            and math.isfinite(value))
-
-
-def validate_rows(record):
-    """Exact schedule, finite numbers (incl. lists) and nonnegative error fields.
-
-    Signed quantities (amplitudes, amplitude/phase errors) keep their sign.
-    Raises ValueError so callers can report an invalid run before any screen.
-    """
-    n, rows = record["n"], record["rows"]
-    steps = [round(tstar * n / U) for tstar in TIMES]
-    if not isinstance(rows, list) or len(rows) != len(steps):
-        raise ValueError("rows do not match the scheduled samples")
-    for row, step in zip(rows, steps):
-        if type(row.get("step")) is not int or row["step"] != step:
-            raise ValueError(f"unscheduled or duplicate step {row.get('step')!r}")
-        if not _number(row.get("tstar")) or abs(row["tstar"] - step * U / n) > 3e-17:
-            raise ValueError(f"wrong sample time at step {step}")
-        if not all(_number(row.get(key)) for key in (*NONNEGATIVE, *SIGNED)):
-            raise ValueError(f"missing or nonfinite diagnostic at step {step}")
-        if any(row[key] < 0 for key in NONNEGATIVE) or row["rho_min"] <= 0:
-            raise ValueError(f"negative error quantity or density at step {step}")
-        levels = row.get("spurious_pressure_scaled_by_level")
-        if (not isinstance(levels, list) or len(levels) != record["depth"]
-                or not all(_number(v) and v >= 0 for v in levels)):
-            raise ValueError(f"invalid per-level pressure at step {step}")
-
-
-def summarize(record):
-    validate_rows(record)
-    rows = record["rows"]
-    n = record["n"]
-    out = fit_rate(rows, n, record["viscosity"])
-    out.update(
-        eps=eps(n),
-        complete=record["completed"] is True,
-        residual_l2=max(r["residual_l2"] for r in rows),
-        phase_drift_abs=max(r["phase_drift_abs"] for r in rows),
-        spurious_pressure_scaled=max(r["spurious_pressure_scaled"] for r in rows),
-        spurious_pressure_rms=max(r["spurious_pressure_rms"] for r in rows),
-        amplitude_error_abs=max(abs(r["amplitude_error"]) for r in rows),
-        velocity_l2=max(r["velocity_l2"] for r in rows),
-        mass_relative=max(r["mass_relative"] for r in rows),
-    )
-    if out["rate_fit_valid"] and not all(
-            _number(v) for v in (out["rate"], out["rate_error"], *out["interval_rate_errors"],
-                                 out["log_fit_residual_max"])):
-        raise ValueError("nonfinite rate fit")
-    out["own_screens_pass"] = out["complete"] and out["rate_fit_valid"] and all(
-        out[key] <= out["eps"] for key in ("rate_error", "phase_drift_abs", "residual_l2")
-    ) and all(out[key] <= limit for key, limit in LIMITS.items())
-    return out
-
-
-def _usable(record):
-    try:
-        out = summarize(record)
-    except (KeyError, TypeError, ValueError):
-        return None
-    return out if out["complete"] else None
-
-
-def assess(base_control, fine_control, refined):
-    """Uniform root-spacing and finest-spacing controls versus refined runs.
-
-    INVALID_CONTROL: missing, incomplete, invalid-row or mixed-source controls.
-    INVALID_RUN: a refined record has invalid rows (schedule, NaN, sign).
-    CONTROL_SCREEN_FAIL: complete valid controls that fail their own screens;
-    refined own-screen results are kept, but no controlled comparison passes.
-    PASS/FAIL: every refined run's controlled_pass (own screens and budgets).
-    """
-    if base_control is None or fine_control is None or not refined:
-        return dict(status="INVALID_CONTROL", reason="missing control or refined run")
-    n = base_control["n"]
-    if (base_control["depth"], fine_control["depth"], fine_control["n"]) != (1, 1, 2 * n):
-        raise ValueError("controls must be uniform N and uniform 2N")
-    if any(r["depth"] != 2 or r["n"] != n for r in refined):
-        raise ValueError("refined runs must be depth 2 at root N")
-    if len({r.get("explosion") for r in refined}) != len(refined):
-        raise ValueError("duplicate refined explosion scheme")
-    sources = {repr(r.get("source")) for r in [base_control, fine_control, *refined]}
-    base, fine = _usable(base_control), _usable(fine_control)
-    if base is None or fine is None or len(sources) != 1:
-        return dict(status="INVALID_CONTROL",
-                    reason="incomplete/invalid control or mixed source")
-    controls_pass = base["own_screens_pass"] and fine["own_screens_pass"]
-    report = dict(base_control=base, fine_control=fine, refined={},
-                  controls_pass=controls_pass)
-    statuses = []
-    for r in refined:
-        try:
-            s = summarize(r)
-        except (KeyError, TypeError, ValueError) as error:
-            report["refined"][r["explosion"]] = dict(valid=False, reason=str(error))
-            statuses.append("INVALID_RUN")
-            continue
-        s["valid"] = True
-        # rate_error is None when a modal fit is unavailable; never a pass.
-        s["budget"] = {
-            key: (None if base[key] is None else max(BASELINE_FACTOR * base[key], floor))
-            for key, floor in FLOORS.items()
-        }
-        s["budget_pass"] = all(
-            s[key] is not None and s["budget"][key] is not None and s[key] <= s["budget"][key]
-            for key in FLOORS)
-        s["control_ratios"] = {
-            name: {key: (s[key] / c[key] if s[key] is not None and c[key] else None)
-                   for key in (*FLOORS, "spurious_pressure_rms")}
-            for name, c in (("root", base), ("finest", fine))
-        }
-        s["controlled_pass"] = controls_pass and s["own_screens_pass"] and s["budget_pass"]
-        report["refined"][r["explosion"]] = s
-        statuses.append("PASS" if s["controlled_pass"] else "FAIL")
-    if "INVALID_RUN" in statuses:
-        report["status"] = "INVALID_RUN"
-    elif not controls_pass:
-        report["status"] = "CONTROL_SCREEN_FAIL"
-    else:
-        report["status"] = "PASS" if all(v == "PASS" for v in statuses) else "FAIL"
-    return report

tests/validation/taylor_green/test_projected_pairs.py

@@ -17,7 +17,6 @@ from unittest.mock import patch
 import numpy as np
 
 import run_case
-import assess_projected_pairs as assessor
 from assess_projected_pairs import (BUILD_SOURCES, CASES, NUMERICS, NUMERICAL_REVISION,
                                     SOURCE_SHA256, assess)
 from oracle import LIMITS, TIMES, U, rectangles
@@ -32,7 +31,7 @@ RUNTIME = dict(device=dict(name="host mock", pci_bus_id="mock", capability=[7, 0
 
 def source():
     return dict(revision=MOCK_REVISION, dirty=False, source_tree_sha256=SOURCE_SHA256,
-                harness_sha256={"run_case.py": "a" * 64, "oracle.py": "c" * 64},
+                harness_sha256={"run_case.py": "a" * 64},
                 build_capture_sha256=run_case.BUILD_CAPTURE_SHA256)
 
 
@@ -43,14 +42,12 @@ def build_metadata(size):
                 arch="sm_70", flags=["--use_fast_math"], ptx_sha256="b" * 64)
 
 
-def records(early=False, diagnostic=None):
+def records(early=False):
     from CelerisLab.lbm.hierarchy import build_hierarchy
     from CelerisLab.lbm.refinement import ACTIVE
 
     out = []
     for re, n, depth, scheme in CASES:
-        if diagnostic:
-            n *= 2
         cfg = run_case.config(n, re)
         refinements = [] if depth == 1 else rectangles(n, depth)
         h = build_hierarchy(cfg, refinements)
@@ -69,8 +66,6 @@ def records(early=False, diagnostic=None):
             early_pressure=dict(enabled=early, rows=[
                 dict(step=s, tstar=s*U/n, pressure_l2=.01 if s not in main_steps else 0.0) for s in early_steps],
                 sampled_max_pressure_l2=.01 if early else None)))
-        if diagnostic:
-            out[-1]["diagnostic"] = diagnostic
     return out
 
 
@@ -256,7 +251,7 @@ class ProjectedPairsTests(unittest.TestCase):
     def test_pinned_build_sources_match_host_generated_inputs(self):
         from CelerisLab.cuda import compiler_v2
 
-        for size in (128, 256, 512):
+        for size in (128, 256):
             cfg = replace(run_case.config(size, 100), nx=10, ny=10)
             cfg.validate()
             root = compiler_v2.generate_config(cfg)
@@ -268,111 +263,6 @@ class ProjectedPairsTests(unittest.TestCase):
             finally:
                 compiler_v2.cleanup_build_dir(root)
 
-    def test_scaled_geometry_work_and_frozen_gates(self):
-        data = records(True, run_case.SCALED_DIAGNOSTIC)
-        self.assertEqual(sum(r["workload"]["active_collision_updates"] for r in data), 4714397696)
-        self.assertEqual([r["viscosity"] for r in data], [.0768, .1536, .0768, .0768])
-        self.assertEqual(data[-1]["tau_by_level"], [.7303999999999999, .9608])
-        for r in data:
-            self.assertEqual([row["tstar"] for row in r["rows"]], TIMES)
-            self.assertEqual(len(r["early_pressure"]["rows"]), 65)
-            if r["depth"] == 2:
-                self.assertEqual(r["refinements"], [[(32, 32, 224, 192)]])
-                self.assertEqual(r["workload"]["active_cells_by_level"], [34816, 122880])
-                self.assertEqual(r["workload"]["level_hops"], [4096, 8192])
-        result = assess(data, MOCK_REVISION, diagnostic=run_case.SCALED_DIAGNOSTIC)
-        self.assertTrue(result["passed"])
-        self.assertEqual(result["floors"], dict(velocity_l2=.002, pressure_l2=.02, energy_relative=.004))
-        self.assertTrue(all(row["floor_dominates"] for row in result["comparisons"]))
-        data[-1]["rows"][-1]["velocity_l2"] = .00200001
-        self.assertFalse(assess(data, diagnostic=run_case.SCALED_DIAGNOSTIC)["passed"])
-        self.assertFalse(assess(data)["passed"])
-        data[-1]["rows"][-1]["velocity_l2"] = 0.0
-        for mutate in (lambda r: r.pop("diagnostic"), lambda r: r.update(diagnostic="wrong"),
-                       lambda r: r["source"].update(revision="wrong"),
-                       lambda r: r["early_pressure"].update(enabled=False),
-                       lambda r: r.update(refinements=[[(32, 32, 224, 200)]])):
-            bad = deepcopy(data)
-            mutate(bad[-1])
-            self.assertFalse(assess(bad, MOCK_REVISION, diagnostic=run_case.SCALED_DIAGNOSTIC)["passed"])
-
-    def test_raw_resolution_changes_and_reference_identity(self):
-        old, new = records(True), records(True, run_case.SCALED_DIAGNOSTIC)
-        for r in old:
-            r["source"]["revision"] = assessor.REFERENCE_REVISION
-        old[-2]["rows"][-1]["velocity_l2"] = .004  # historical constant failure remains usable
-        old[-1]["rows"][-1]["velocity_l2"] = .001
-        new[-1]["rows"][-1]["velocity_l2"] = .0015  # floor pass, but worse raw error
-        result = assessor.resolution_trend(new, old, MOCK_REVISION)
-        self.assertTrue(result["valid"])
-        self.assertTrue(result["trend_interpretation_ready"])
-        self.assertFalse(result["reference_scheme_results"]["constant"]["passed"])
-        self.assertEqual((len(result["per_time"]), len(result["worst_post_initial"]),
-                          len(result["uniform256_bridge"])), (80, 16, 20))
-        row = next(r for r in result["per_time"] if r["role"] == "projected_linear"
-                   and r["metric"] == "velocity_l2" and r["tstar"] == .48)
-        self.assertEqual((row["signed_change"], row["new_to_old"], row["change_percent"]), (.0005, 1.5, 50.))
-        self.assertTrue(assess(new, diagnostic=run_case.SCALED_DIAGNOSTIC)["passed"])
-        self.assertIsNone(result["per_time"][0]["new_to_old"])  # zero denominator is explicit
-        self.assertEqual(result["per_time"][0]["ratio_unavailable_reason"], "zero historical error")
-        new[-1]["rows"][-1]["velocity_l2"] = .06  # retain raw errors even when absolute screen fails
-        self.assertTrue(assessor.resolution_trend(new, old, MOCK_REVISION)["valid"])
-        self.assertFalse(assess(new, diagnostic=run_case.SCALED_DIAGNOSTIC)["passed"])
-        new[-1]["rows"][-1]["velocity_l2"] = .0015
-        for sample in ("rows", "early_pressure"):
-            bad = deepcopy(new)
-            if sample == "rows":
-                bad[0]["rows"][-1]["velocity_l2"] = .0001
-            else:
-                bad[0]["early_pressure"]["rows"][1]["pressure_l2"] = .009
-            result = assessor.resolution_trend(bad, old, MOCK_REVISION)
-            self.assertTrue(result["valid"])
-            self.assertFalse(result["trend_interpretation_ready"])
-        for mutate in (lambda r: r["source"].update(revision=MOCK_REVISION),
-                       lambda r: r["source"].update(source_tree_sha256="wrong"),
-                       lambda r: r["source"]["harness_sha256"].update(**{"oracle.py": "wrong"}),
-                       lambda r: r.update(diagnostic=run_case.SCALED_DIAGNOSTIC),
-                       lambda r: r.update(refinements=[]), lambda r: r["rows"].pop()):
-            bad = deepcopy(old)
-            mutate(bad[-1])
-            self.assertFalse(assessor.resolution_trend(new, bad, MOCK_REVISION)["valid"])
-        with tempfile.TemporaryDirectory() as tmp:
-            paths = [Path(tmp) / f"{i}.json" for i in range(4)]
-            for path, receipt in zip(paths, old):
-                path.write_text(json.dumps(receipt))
-            with self.assertRaisesRegex(ValueError, "receipt hashes"):
-                assessor.load_reference(paths)
-            witnesses = {p.name: hashlib.sha256(p.read_bytes()).hexdigest() for p in paths}
-            with patch.object(assessor, "REFERENCE_RECEIPTS", witnesses):
-                self.assertEqual(assessor.load_reference(paths), json.loads(json.dumps(old)))
-                with self.assertRaises(ValueError):
-                    assessor.load_reference(paths[:-1] + paths[:1])
-                paths[-1].write_text(paths[-1].read_text() + " ")
-                with self.assertRaises(ValueError):
-                    assessor.load_reference(paths)
-
-    def test_scaled_runner_requires_explicit_bounded_diagnostic(self):
-        with tempfile.TemporaryDirectory() as tmp:
-            base = ["run_case.py", "--repo", str(REPO), "--expected-revision", MOCK_REVISION,
-                    "--output", str(Path(tmp) / "case.json"), "--dry-run"]
-            diagnostic = ["--diagnostic", run_case.SCALED_DIAGNOSTIC, "--early-pressure"]
-            for n, depth, re, extra, valid in (
-                    (512, 1, 100, [], False), (512, 1, 100, diagnostic, True),
-                    (256, 2, 100, diagnostic, True), (128, 2, 100, diagnostic, False),
-                    (256, 3, 100, diagnostic, False), (256, 2, 1000, diagnostic, False),
-                    (256, 2, 100, diagnostic[:2], False), (512, 2, 100, diagnostic, False)):
-                argv = base + ["--n", str(n), "--depth", str(depth), "--re", str(re)] + extra
-                with self.subTest(argv=argv), patch.object(sys, "argv", argv), \
-                     patch.object(run_case, "verify_source", return_value=source()) as verify, \
-                     redirect_stdout(io.StringIO()), patch("sys.stderr", io.StringIO()):
-                    if valid:
-                        self.assertEqual(run_case.main(), 0)
-                    else:
-                        with self.assertRaises(SystemExit) as caught:
-                            run_case.main()
-                        self.assertEqual(caught.exception.code, 2)
-                        verify.assert_not_called()
-
     def test_source_preflight_requires_clean_exact_revision_and_tree(self):
         import oracle
         from tests.validation.multigrid import check_projected_pairs as gate
@@ -429,7 +319,7 @@ class ProjectedPairsTests(unittest.TestCase):
                  patch.object(run_case, "runtime_identity", side_effect=AssertionError("CUDA reached")), \
                  redirect_stdout(stdout):
                 self.assertEqual(run_case.main(), 0)
-            verify.assert_called_once_with(REPO, MOCK_REVISION, "taylor_green")
+            verify.assert_called_once_with(REPO, MOCK_REVISION)
             self.assertTrue(json.loads(stdout.getvalue())["dry_run"])
             self.assertFalse(output.exists())
 
@@ -459,15 +349,9 @@ class ProjectedPairsTests(unittest.TestCase):
 
     def test_mocked_runner_default_early_and_failure(self):
         # Replace the GPU context and steppers before import. No CUDA module or flow is used.
-        cases = [(early, depth, fail, 128, None, "projected_linear" if early else "constant")
-                 for early, depth, fail in
-                 ((False, 1, None), (False, 2, None), (True, 2, None),
+        for early, depth, fail in ((False, 1, None), (False, 2, None), (True, 2, None),
                                    (True, 2, "resource"), (True, 2, "nonfinite"),
-                                   (True, 2, "probe_nonfinite"))]
-        cases += [(True, depth, None, n, run_case.SCALED_DIAGNOSTIC, scheme)
-                  for n, depth, scheme in ((256, 1, "constant"), (512, 1, "constant"),
-                                          (256, 2, "constant"), (256, 2, "projected_linear"))]
-        for early, depth, fail, n, diagnostic, scheme in cases:
+                                   (True, 2, "probe_nonfinite")):
             calls, selectors = [], []
 
             class FakeRun:
@@ -511,14 +395,11 @@ class ProjectedPairsTests(unittest.TestCase):
 
             with tempfile.TemporaryDirectory() as tmp:
                 output = Path(tmp) / "case.json"
-                argv = ["run_case.py", "--repo", str(REPO), "--re", "100", "--n", str(n),
+                argv = ["run_case.py", "--repo", str(REPO), "--re", "100", "--n", "128",
                         "--depth", str(depth), "--output", str(output),
                         "--expected-revision", MOCK_REVISION, "--run-gpu"]
-                argv += ["--explosion", scheme]
                 if early:
-                    argv += ["--early-pressure"]
-                if diagnostic:
-                    argv += ["--diagnostic", diagnostic]
+                    argv += ["--early-pressure", "--explosion", "projected_linear"]
                 with patch.dict(sys.modules, modules), patch.object(sys, "argv", argv), \
                      patch.dict("os.environ", CUDA_VISIBLE_DEVICES="mock"), \
                      patch.object(run_case, "verify_source", return_value=source()) as verify, \
@@ -531,17 +412,16 @@ class ProjectedPairsTests(unittest.TestCase):
                     else:
                         self.assertEqual(run_case.main(), 0)
                 receipt = json.loads(output.read_text())
-                verify.assert_called_once_with(REPO, MOCK_REVISION, "taylor_green")
-                self.assertEqual(selectors, [scheme] if depth == 2 else [])
+                verify.assert_called_once_with(REPO, MOCK_REVISION)
+                self.assertEqual(selectors, ["projected_linear" if early else "constant"] if depth == 2 else [])
                 self.assertEqual(receipt["source"], source())
                 self.assertEqual(receipt["runtime_identity"], RUNTIME)
                 self.assertEqual(receipt["completed"], not fail)
-                self.assertEqual(receipt.get("diagnostic"), diagnostic)
                 self.assertEqual(calls[:2], [0, 1])  # READY probe is part of this trajectory
                 if not fail:
                     self.assertEqual([r["tstar"] for r in receipt["rows"]], TIMES)
                     self.assertEqual(len(receipt["early_pressure"]["rows"]), 65 if early else 0)
-                    self.assertEqual(calls[-1], 16*n)
+                    self.assertEqual(calls[-1], 2048)
                 else:
                     self.assertEqual(len(receipt["rows"]), 1)
                     self.assertEqual(len(receipt["early_pressure"]["rows"]),

tests/validation/time_refined_dfg.py

@@ -173,8 +173,9 @@ def time_refined(a, h, sched):
         cfg, pair, body, host = r.host_geometry(a.source, h, "MRT")
         context = stack.enter_context(CudaContext(0))
         backend = stack.enter_context(FixedPatchStepper(
-            cfg, r.BOUNDS, context=context, coarse_boundary="channel", base_block=r.BASE_BLOCK,
-            fine_block=r.FINE_BLOCK, fine_objects=(body,), observe_raw_exchange=True))
+            cfg, context=context, coarse_boundary="channel", refinements=[r.BOUNDS],
+            level_blocks=[r.BASE_BLOCK, r.FINE_BLOCK], level_objects=[(), (body,)],
+            observe_raw_exchange=True))
         masks = [channel_masks(pair.coarse_shape)[0] & ~pair.covered,  # as run_refined_dfg
                  (pair.fine_kind == ACTIVE) & ((host.flags.reshape(pair.fine_shape) & SOLID) == 0)]
         fresh = (r.initial_state(pair.coarse_shape, (0.0, 0.0), 1.0, root=True),

tests/validation/time_window_dfg.py

@@ -130,8 +130,8 @@ def main():
         cfg, pair, body, host = r.host_geometry(a.source, h, "MRT")
         context = stack.enter_context(CudaContext(0))
         backend = stack.enter_context(FixedPatchStepper(
-            cfg, r.BOUNDS, context=context, coarse_boundary="channel", base_block=r.BASE_BLOCK,
-            fine_block=r.FINE_BLOCK, fine_objects=(body,), observe_raw_exchange=True,
+            cfg, context=context, coarse_boundary="channel", refinements=[r.BOUNDS],
+            level_blocks=[r.BASE_BLOCK, r.FINE_BLOCK], level_objects=[(), (body,)], observe_raw_exchange=True,
             observe_window_exchange=True))
         masks = [channel_masks(pair.coarse_shape)[0] & ~pair.covered,
                  (pair.fine_kind == ACTIVE) & ((host.flags.reshape(pair.fine_shape) & SOLID) == 0)]