Apply ruff format across the codebase

Whitespace-only reflow (line wrapping, blank lines between defs); no
logic changes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

analysis/compare_ode_steps_kl.py

@@ -66,6 +66,4 @@ print(
     f"{'SUM':<14}{tot['10-step']:>14.5f}{tot['20-step']:>14.5f}"
     f"{tot['20-step'] / tot['10-step']:>14.2f}"
 )
-print(
-    f"{'MEAN':<14}{tot['10-step'] / 9:>14.5f}{tot['20-step'] / 9:>14.5f}"
-)
+print(f"{'MEAN':<14}{tot['10-step'] / 9:>14.5f}{tot['20-step'] / 9:>14.5f}")