Spec for porting retail's CameraManager + CameraSet behavior to a new
RetailChaseCamera class, controlled by a CameraDiagnostics toggle so the
user can A/B against legacy ChaseCamera. Covers six retail behaviors:
exponential damping (stiffness*dt*10), 5-frame velocity-averaged slope
alignment, mouse low-pass (0.25s window), held-key offset integration,
auto-fade <0.45m, and independent translation/rotation stiffness rates.
Brainstormed end-to-end before any code change.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
