Decision 2026-05-11: 'highVolumeSafetyLevel' is canonical. The legacy 'overfillLevel' name is gone from computeSafetyPoints + the validator issue tuple. 'overfillVol' parallel alias kept (out of scope for this task; flagged for follow-up). 130/130 tests pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>