- Add `avatar_path` column to users table via migration 008
- Integrate `cropperjs` and `sharp` for avatar upload, cropping (600×600), and PNG conversion
- Serve avatars at `/media/avatars` with static caching; expose `/static/vendor/cropperjs`
- Add avatar management UI in account settings with modal cropping workflow
- Display creator avatars on song/playlist detail pages (fallback to initial)
- Implement generic image lightbox (`lightbox.js`) for cover art with zoom animations and keyboard support
- Refactor song/playlist detail views to use responsive layout and lightbox-enabled covers
