Adds CellTransitTests with two A6P5_* unit tests:
A6P5_BuildCellSetFromIndoorStart_ReachesDoorOutdoorCell (RED — the bug)
A6P5_BuildCellSetFromAlcove_AlsoReachesDoorOutdoorCell (passes today)
The RED test reproduces the over-penetration tick's cellSet build:
sphere at (132.594, 16.350) in cell 0xA9B4013F, BFS portal-walks to
0xA9B40150 (alcove) but does NOT add the door's outdoor cell 0xA9B40029.
Pre-fix cellSet: 0xA9B4013F, 0xA9B40150, 0xA9B4014C — no outdoor cells.
Sphere wasn't straddling 0xA9B40150's exit portal so exitOutside stayed
false.
Also removes the 3 A6P5_* replay tests added to
DoorBugTrajectoryReplayTests in the previous commit (3253d84's
follow-up). Those tests didn't reproduce the bug — the harness's
BuildFaithfulDoorEngine has no cell fixtures, so cellSet returned empty
and GetNearbyObjects treated it as "no filter" → door always visible
→ over-penetration test trivially passed for the wrong reason. The
CellTransitTests version pins the bug at the BFS layer directly.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
