Migrate current callers to level-indexed refinement API

examples/fixed_patch_circle.py

@@ -40,13 +40,13 @@ def config(mode):
 def leaf_masks(run, mode):
     """Known fluid leaves: uncovered coarse cells (minus wall rows in slot mode)
     and fine ACTIVE cells outside the body."""
-    p = run.patch
+    p = run.hierarchy.pairs[0]
     x0, y0, x1, y1 = p.bounds
     coarse = np.ones(p.coarse_shape, bool)
     coarse[y0:y1, x0:x1] = False
     if mode == "slot_reservoir":
         coarse[[0, -1]] = False
-    solid = (run.fine_boundary.flags.reshape(p.fine_shape) & SOLID) != 0
+    solid = (run.boundaries[1].flags.reshape(p.fine_shape) & SOLID) != 0
     return coarse, (p.fine_kind == ACTIVE) & ~solid
 
 
@@ -94,7 +94,7 @@ def main():
             cfg, context=context, coarse_boundary=args.mode, refinements=[BOUNDS],
             level_blocks=[tuple(args.base_block), tuple(args.fine_block)],
             level_objects=[(), (body,)]) as run:
-        p = run.patch
+        p = run.hierarchy.pairs[0]
         # Rest equilibrium is already postcollision G, so no initial collision is
         # needed. Non-leaf entries (covered, ghost, solid) are discarded by initialize.
         rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]