feat: statistics upgrade, playlists redesign, artist cards, and UX improvements (v1.4.0)

- Statistics page: library stat cards, recently played, most played, highest rated, genre chart
- Playlists page: list layout with sort (Name/Tracks/Duration) and filter input
- Favorites songs: full tracklist layout with artist column, context menu, enqueue-all button
- AlbumDetail: extracted AlbumHeader and AlbumTrackList components
- Artist cards: square cover, same sizing as album cards (clamp 140-180px)
- Random Albums: removed renderKey remount, added loadingRef guard, fixed manual refresh race
- Context menu: "Go to Album" option for song and queue-item types
- Queue panel meta box: artist → artist page, album → album page, removed year
- Random Mix: hover persistence via .context-active class while context menu is open
- i18n: "Warteschlange" consistently used for queue in German

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "psysonic",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "private": true,
   "scripts": {
     "dev": "vite",