Reduced motion support and performance limits on visual effects

The heavy visuals run unconditionally. BlurryHeader renders 15-80 blurred divs animating forever on every detail page, the home page AlbumScroller renders the entire album collection six times over as rotated images, and there's no prefers-reduced-motion handling anywhere despite framer-motion on nearly every component.

• Honour prefers-reduced-motion: global CSS clamp on animation durations plus useReducedMotion for the big framer-motion entrances
• BlurryHeader: cap blob count properly, static gradient fallback on mobile
• Home marquee: backend endpoint returns a capped random sample (say 50) with small image variants instead of the full collection, and drop the six-times duplication to what the loop actually needs