Audit and fix animation performance issues including layout thrashing, compositor properties, and scroll-linked motion.

• Covers nine rule categories by priority: never patterns, mechanism selection, measurement batching, scroll-linked motion, paint optimization, layer promotion, blur/filter constraints, view transitions, and tool boundaries
• Provides file-level review mode that identifies violations with exact line quotes, impact explanation, and concrete code fixes
• Includes FLIP-style transition patterns, scroll timeline alternatives to JS polling, and guidance on batching DOM reads before writes
• Applies constraints within existing animation stacks without forcing library migrations