274cf3b791
The room-exit portal was invisible in the first playtest - players loitered out the 30s ExploreGrace timeout. Adds RegionMath.ExpeditionPortalPos as the single client-derivable portal-position authority (HUD prompt + beacon can't drift), a pooled breathing HDR pillar in CombatFeedbackSystem shown only during RoomExplore, and an in-range/out-of-range two-stage prompt. Also repairs the comment-swallowed _portalMat initialization (NRE in OnStartRunning killed ALL combat feedback each session and auto-paused the editor via Error Pause). 456/456 EditMode. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>