fix(skills): consolidate animation-map capture reliability

[miguel-heygen]

Summary

• pass rational frame-rate values to animation-map and contrast capture helpers
• batch animation-map sampling into one browser evaluation to avoid per-sample timeout overhead
• add regression coverage for both capture contracts

Consolidates and replaces #2339 and #2329.

Verification

• node --test skills/hyperframes-animation/scripts/animation-map.test.mjs skills/hyperframes-animation/scripts/animation-map-sampling.test.mjs (3 passed)
• skills manifest regenerated and in sync
• git diff --check