Add a deterministic stubbed-rAF test for animateView's animated path (was only
covering the reduced-motion branch) and assert the server load redirects on 401
and throws on a network 500 (QA review).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Fit-to-screen tweens to the default view over 300ms via animateView (eased,
lerpView-driven) and snaps instantly when prefers-reduced-motion is set
(US-PAN-004 AC2, NFR-A11Y-003).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>