P1 (2/n): runners and example use the level-list constructor

run_refined_dfg, run_dfg_re20, time_window_dfg, time_refined_dfg,
run_jet_circle_cv and examples/fixed_patch_circle pass refinements /
level_blocks / level_objects / level_jets instead of bounds, base_block,
fine_block, fine_objects and jets. One-to-one with _legacy_levels: same
rectangle (FixedPatch2D frame), same blocks, bodies and Jets.

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

tests/validation/run_jet_circle_cv.py

@@ -279,12 +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,
     ):