From the Hoshe/Tyre review:
- drainage: assert flow_accumulation/max_accumulation determinism + clamp ≥ 1
(the D-209 strength denominator); isolated-basin merge path (no panic).
- subbiome: each derivable variant reachable + Volcanic never emitted.
- planet_simulation: new test_sim_determinism.py — same body simulates to a
bit-identical elevation array at 1024×512 (the 271-body bake can't be cheaply
re-run, so a silent drift = full re-bake). Verified PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>