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>

README.md

@@ -170,3 +170,11 @@ Files are kept in the data folder under `mystore/` (up to 1 GB each; extensions
 
 **Music, Featured:** the first tab of Music shows a featured artist and a featured album, picked at random. They stay the same for the day on that device; *Pick again* rolls new ones. *Based on* chooses which playlists they come from (nothing chosen means the whole library), and that choice follows you between devices. *Play mix* shuffles the artist's songs; *Play* plays the album in order.
 
+**Music, more** (Plex music; what is about a person is kept by the hub in `music-*.json` in their folder, and `music-family.json` for Family playlists):
+- **Mixes tab:** a Daily mix (what you play, your favorites and a few surprises), Most played this month, Forgotten favorites, Moods (calm, upbeat, focus, worship, built from your genres), On this day (albums released today in past years), Decades, Genres (each with a featured album and a shuffle), *Library radio* (an endless shuffle that keeps adding songs; it uses the playlists chosen on Featured), and **Smart playlists**: your own rules (genres, years, added recently, not played in a while, played at least N times, favorites only, order, size) that pick songs each time you open them.
+- **Favorites:** a heart on songs (in lists, the full player and the song menu); the Favorites page plays them. Kept by the hub, so they follow you between devices.
+- **Stats tab:** songs played, time listened, artists, day streak, minutes per day or month, top artists, songs and albums, and recently played; for a week, month, year or all time. A song counts when it has been played for half its length. *Clear my history* starts over.
+- **Family playlists** (Playlists tab, and *Add to playlist* on any song): shared by everyone who has Music; anyone can add or remove songs, only the owner or an admin renames or deletes one.
+- **Also:** reorder the queue with the arrows; *More like this* on an artist or song; an About note on albums and artists (Plex's own summary); **Save offline** on an album (plays with no signal); the player takes its colors from the album cover; **Share a line** in the lyrics makes a picture of the lyric over the cover; Featured shows a verse of the day when you have the Bible tab.
+- Not included: crossfade or gapless (the player already keeps the next songs downloaded for quick changes), searching lyrics by a line, and a speaker picker.
+