Explicit stream synchronization before/after each timed loop (refined
FixedPatchStepper stream, uniform Simulation stream, in their contexts);
required --max-wall-seconds outer timeout checked between variants and in
per-step loops; untimed finite leaf/fluid health checks; force notes for
B/C/E' (no host reads; final base interval only; whole-window average with
different summation order). Parity stays A/B/C vs A and E/E' vs E only.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
