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_refined_dfg.py

@@ -383,13 +383,12 @@ def run_case(a, h, periodic, case):
             backend = stack.enter_context(
                 FixedPatchStepper(
                     cfg,
-                    PLACEMENTS[a.placement],
                     context=context,
                     coarse_boundary="channel",
-                    base_block=BASE_BLOCK,
-                    fine_block=FINE_BLOCK,
-                    fine_objects=(body,),
-                    jets=public_jets((80.5, 81.0), 20.0, a.jet_scenario),
+                    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 {}),
                 )