Port retail CObjCell::find_cell_list do_not_load_cells prune
(acclient_2013_pseudo_c.txt:308829-308867) as indoor->outdoor doorway
hysteresis: hold the previous indoor cell when the outdoor candidate is
not in its stab list AND the foot-sphere still overlaps the cell's
containment BSP expanded by DoorwayHoldMargin. Kills the front-door
0170<->0031 ping-pong (handoff §5) the #98 saga never addressed. Fires
only at the front-door seam; the cellar has no exit portal so it never
falls through here (#98 cellar-up untouched).
Three TDD tests in CellGraphMembershipTests: HOLD (the RED->GREEN case,
Y=3.9 inside the 0.2 m margin), RELEASE when fully outside (Y=4.5
exceeds expanded margin), and stab-list gate (outdoor candidate in stab
list releases even near the boundary).
Adds using System.Linq for IReadOnlyList.Contains at the prune site.
SphereOverlapsEnvCell helper mirrors BSPQuery.SphereIntersectsCellBsp
via EnvCell.InverseWorldTransform + ContainmentBsp.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add private `SetCurrAndReturn(uint)` helper in PhysicsEngine that looks up
the resolved id in `DataCache.CellGraph` and writes `CurrCell` when the cell
is present. Wrap the four RESOLVED-id return sites in ResolveCellId:
- indoor no-CellBSP return (trust FindCellList)
- indoor sphere-overlaps-CellBSP return
- outdoor→indoor building-transit return (foreach candidate)
- outdoor terrain-grid return
The final no-match `return fallbackCellId;` is intentionally NOT wrapped —
stale beats null (the caller's seed is preserved unchanged).
CurrCell has zero readers in src/ (verified by ripgrep); this is additive
write-only, identical observable behavior to W1. One new unit test
(CellGraphMembershipTests) proves RED→GREEN.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>