Review verdict updated to Approved; all blocking issues and suggestions
resolved and documented. Add auto-generated Godot .uid sidecar files for
occlusion_policy.gd and occlusion_policy_test.gd.
Fixes review blocking issue: when the follow target is null (freed,
renamed, or path unresolved) or the Camera3D child is missing,
_restore_all_occluders() is now called before returning so geometry
cannot be left stuck semi-transparent.