The visibility root + portal-side test now use the PLAYER position (visRootPos) in
player mode instead of the camera EYE; the eye still drives the per-frame projection
(envCellViewProj). Live ACDREAM_PROBE_FLAP evidence: the flap was the 3rd-person eye
drifting out of the player's cell -> FindCameraCell returning the STALE cell for its
grace frames -> the doorway portal culled as behind-the-eye -> exit cell + terrain +
shells dropped (res=Grace eyeInRoot=n terrain=Skip on every flap frame). Retail's
CellManager::ChangePosition (0x004559B0) tracks curr_cell by the player; acdream
already roots lighting at the player (GameWindow:7152) for the same chase-cam reason
— visibility was the lone holdout on the eye. Removed the earlier synthetic builder
flap test, which modeled a disproven (side-test) hypothesis; the fix is integration-
level, validated by the visual gate + [flap] probe. App tests 151/151.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>