P0 Task 6 complete. Captured live retail membership at the 0031<->0170<->0171
doorway via cdb on CPhysicsObj::change_cell (symbol-driven; offsets verified by
discover-types.cdb; PDB MATCH). 22 transitions, clean monotonic sequence, NO
ping-pong (retail is correct-by-construction). Golden:
Conformance/Fixtures/find-cell-list-threshold.log.
ROOT-CAUSE FINDING (the central P1 work): retail transitions membership at the
PORTAL CROSSING (CEnvCell::find_transit_cells @ 0x52c820 pc:309968 — sphere crosses
the doorway polygon plane), while acdream's FindCellList re-picks by POINT-IN-CELL
containment at the foot. Retail commits room 0171 while the foot is STILL inside
vestibule 0170's BSP (in_0171=0); acdream lags. ALL 22 transitions diverge for this
one criterion mismatch — not a per-cell hysteresis or a building-entry-only split.
This is master-plan §0 'hysteresis gap' confirmed against the real client.
FindCellList_DoorwayThreshold_DivergesFromRetail_PendingP1 (documents-the-bug, GREEN)
+ ThresholdDivergenceDiagnosticTests (per-transition containment print) pin it; both
flip when P1 ports the directed portal crossing. Conformance 59 pass / 1 skip / 0 fail;
full Core 1308 pass / 5 fail (baseline) / 1 skip — no new failures.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>