Design for porting retail's stage-2 camera collision (SmartBox::update_viewer):
sweep a 0.3 m sphere from the head-pivot to the damped eye via the existing
ResolveWithTransition engine (collides both indoor cell walls and GfxObj
building shells, e.g. the cottage cellar per #98/#101), publish the stopped
position as the eye. Fixes the A8.F flap by keeping the eye out of walls so the
camera-cell + portal side-tests stay stable. Self-skip via LocalEntityId; gated
by CameraDiagnostics.CollideCamera (default ON). Corrects the prior
retail-chase-camera spec's "no camera collision" note.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
