Search results now show "In Library" badges on albums and tracks
that already exist in the user's library. Badges appear with a
staggered fade-in animation after results render (non-blocking).
- Backend: /api/enhanced-search/library-check endpoint builds
owned album/track sets in 2 queries, O(1) lookups per result
- Frontend: async call after render, 30ms stagger per badge
- Tracks in library get play button rewired for direct playback
from media server instead of searching download sources
- Fixed enhanced search album card text not visible (info div
now absolute-positioned with gradient overlay)
- Download manager panel hidden by default for more search space