Change A (TransitionTypes.FindEnvCollisions:~1947): replace the unconditional
static ResolveCellId re-derive with the SWEPT find_cell_list pick via
CellTransit.FindCellSet. When DataCache is available (always in production),
the swept pick runs and resolves the containing cell from the portal-graph
candidate set. When DataCache is null (test engines without a cell registry),
the old ResolveCellId fallback is preserved to keep PhysicsEngineTests green.
Change B (CellTransit.BuildCellSetAndPickContaining): replace the containment
loop that silently skipped all outdoor candidates (CellBSP=null) with the
retail CObjCell::find_cell_list interior-wins pick (pseudo_c:308788-308819):
interior EnvCells win first; if no interior cell contains the center, fall
to the outdoor XY-grid column (CLandCell::point_in_cell equivalent). This is
the missing half of find_cell_list that caused the 0xA9B40170↔0xA9B40031
doorway cell-strobe — the swept pick previously always returned currentCellId
for outdoor candidates, letting the static re-derive at :1947 strobe on every
tick from a different result.
DoorwayMembershipReplayTests: two facts, loads doorway-capture.jsonl (364K records,
strobing live run), filters to Y∈[15.5,17.5] seam zone (57 records), verifies
FindCellSet produces exactly 1 transition (enter indoor → stay outdoors) with
zero A→B→A ping-pong across the full window. Second test verifies outdoor-seed
records round-trip correctly via the XY-grid formula. Both pass.
LiveCompare_FirstCap_FixClosesCottageFloorCap: still passes (issue #98 gate intact).
Full Core suite: 15 failures (within documented flaky baseline of 14–19;
all 15 are pre-existing static-leak/document-the-bug tests, zero new regressions
in cell/transit/BSP/physics classes).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>