examples: fixed_patch_circle reports its blocked tiles (fix unbound fine_block)

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

examples/fixed_patch_circle.py

@@ -2,7 +2,7 @@
 
 From this checkout, after checking the selected physical GPU is idle:
     PYTHONPATH="$PWD/src" CUDA_VISIBLE_DEVICES=0 python examples/fixed_patch_circle.py
-    ... --speed -0.002 --mode slot_reservoir --fine-block 8 8
+    ... --speed -0.002 --mode slot_reservoir
 Both levels use blocked storage (--base-block, --fine-block tiles).
 
 A short smoke run (default 128 coarse steps): it shows setup, stepping and
@@ -100,8 +100,8 @@ def main():
         rest = np.asarray(compute_feq_d2q9(1.0, 0.0, 0.0), np.float32)[:, None, None]
         run.initialize(np.broadcast_to(rest, (9, *p.coarse_shape)),
                        np.broadcast_to(rest, (9, *p.fine_shape)))
-        storage = f"blocked {fine_block}" if fine_block else "dense"
-        print(f"mode={args.mode} fine storage={storage} speed={args.speed:+g} "
+        storage = f"blocked root {tuple(args.base_block)} fine {tuple(args.fine_block)}"
+        print(f"mode={args.mode} storage={storage} speed={args.speed:+g} "
               f"(fine allocation {p.fine_shape[0]}x{p.fine_shape[1]}, fine origin {p.fine_origin})")
         masks = leaf_masks(run, args.mode)
         start = leaf_diagnostics(*run.download(), masks)