Music: Mixes, Favorites and Stats; smart and Family playlists; library radio; offline albums; more

- Mixes tab: daily mix, most played, forgotten favorites, moods, on this day, decades, genres, smart playlists (rules), library radio
- Favorites (hearts, kept by the hub) and Stats (plays, time, top artists/songs/albums, streak, recently played)
- Family playlists shared by everyone with Music; queue reorder; More like this; album/artist About notes
- Save albums offline; player takes colors from the cover; Share a lyric line as a picture; verse of the day on Featured
- musicdata.js keeps plays, favorites, smart rules and Family playlists, with tests

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/music-extras.js

@@ -29,6 +29,7 @@ async function addToPlaylist(tracks, suggest = '') {
   }, suggest);
   actionSheet('Add to playlist', keys.length + (keys.length === 1 ? ' track' : ' tracks'), [
     { label: 'New playlist…', icon: 'plus', run: newOne },
+    ...(typeof addToFamily === 'function' ? [{ label: 'A Family playlist…', icon: 'music', run: () => addToFamily(tracks) }] : []),
     ...lists.map(p => ({ label: p.title, icon: 'music', run: async () => { try { await plx.add(p.ratingKey, keys); toast('Added to ' + p.title); if (location.hash === '#/music/playlist/' + p.ratingKey) route(); } catch (e) { toast(e.message); } } })),
   ]);
 }