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/app.js

@@ -95,6 +95,8 @@ const ICONS = {
   cal: '<rect x="3" y="5" width="18" height="16" rx="2"/><path d="M3 10h18M8 3v4M16 3v4"/>',
   store: '<path d="M4 9l1.5-5h13L20 9M4 9v11h16V9M4 9c0 1.7 1.3 3 3 3s3-1.3 3-3c0 1.7 1.3 3 3 3s3-1.3 3-3 1.3 3 3 3"/><path d="M10 20v-5h4v5"/>',
   download: '<path d="M12 4v11M7 11l5 5 5-5M5 20h14"/>',
+  arrup: '<path d="M6 14l6-6 6 6"/>',
+  arrdn: '<path d="M6 10l6 6 6-6"/>',
   chef: '<path d="M7 14a4 4 0 11.8-7.9A4 4 0 0116 6.5 4 4 0 0117 14v6H7z"/><path d="M7 17h10"/>',
   people: '<circle cx="9" cy="8" r="3.5"/><path d="M2.5 20a6.5 6.5 0 0113 0M16 4.5a3.5 3.5 0 010 7M18 14a6 6 0 013.5 6"/>',
   search: '<circle cx="11" cy="11" r="7"/><path d="M20 20l-4-4"/>',