Lyrics and karaoke for the music player

- full-screen lyrics view that follows the song: highlighted current line with a colour sweep (word by word when the source has word timing), tap a line to jump, text size, timing nudge, 'Wrong lyrics?' search
- Karaoke mode: the current line large and centered
- lyrics from Plex first, then the bundled Lyrica service (LRCLIB, Musixmatch via Lrcmux, NetEase, Megalobiz); YouTube captions never used; wrong-length recordings refused; answers kept in /data/lyrics
- lyrica/: Lyrica pinned to one commit, built by the workflow as hub-lyrica; compose service sharing the hub's network
- tools/lyrics-test.js

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

docker-compose.yml

@@ -23,6 +23,7 @@ services:
       WEBMAIL_BACKEND_URL: http://127.0.0.1:80               # the bundled webmail (Cypht, below, shares this container's network); the hub shows it at /webmail/
       CYPHT_USER: ${CYPHT_USER:-hub}                         # the webmail's login; the Mail tab signs in with it for you
       CYPHT_PASSWORD: ${CYPHT_PASSWORD:-}
+      LYRICS_API_URL: http://127.0.0.1:9999                  # the bundled lyrics service (Lyrica, below, shares this container's network); remove this line and the service to skip it
       SIGNAL_API_URL: http://127.0.0.1:8085                  # the bundled Signal bridge (below, shares this container's network); remove this line and the service to skip Signal
       PODCAST_URL: ${PODCAST_URL:-https://podcast.necloud.us/}
       ONLYOFFICE_JWT_SECRET: ${ONLYOFFICE_JWT_SECRET:-}    # same value as the OnlyOffice server's JWT secret
@@ -72,6 +73,18 @@ services:
     volumes:
       - signal-data:/home/.local/share/signal-cli
 
+  # Lyrics and karaoke for the music player. Lyrica looks songs up on public lyrics sources (LRCLIB, Musixmatch via Lrcmux, NetEase, Megalobiz);
+  # the song's artist and title are sent to them. Plex's own lyrics are used first when the song has them. See README -> Music.
+  lyrica:
+    image: git.necloud.us/nate/hub-lyrica:latest   # built by the Gitea workflow from ./lyrica (Lyrica pinned to one commit)
+    build: ./lyrica
+    restart: unless-stopped
+    network_mode: "service:hub"       # reached by the hub at 127.0.0.1:9999 and by nothing else
+    depends_on:
+      - hub
+    environment:
+      PORT: "9999"
+
 volumes:
   hub-data:
     name: nehub-data   # fixed name so the data survives redeploys and renamed stacks