feat: synced lyrics view in Now Playing overlay

Adds a Lyrics tab to the NP overlay using Navidrome's getLyricsBySongId
endpoint. Synced lyrics auto-scroll and highlight the current line as
the track plays; tapping a line seeks to that position. Falls back to
plain text for unsynced lyrics.

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

src/player.js

@@ -1,8 +1,9 @@
 import { S } from './state.js';
 import { esc, formatDur, toast } from './utils.js';
 import { api, streamUrl, coverUrl, downloadUrl } from './api.js';
-// views.js circular import — safe because only used inside function bodies
+// views.js/ui.js circular imports — safe (only used inside function bodies)
 import { loadRecommendations } from './views.js';
+import { updateLyricsHighlight, onNpSongChange } from './ui.js';
 
 // ─── PLAYBACK ───
 export function playQueue(songs, startIdx) {
@@ -19,6 +20,7 @@ export function playCurrent() {
   S.audio.src = streamUrl(s.id);
   S.audio.play();
   updatePlayerUI(s);
+  onNpSongChange(s.id);
   renderQueue();
 }
 
@@ -153,6 +155,7 @@ export function updateProgress() {
     if(fill) fill.style.width = p + '%';
     if(cur)  cur.textContent  = formatDur(S.audio.currentTime);
     if(tot)  tot.textContent  = formatDur(S.audio.duration);
+    if(S.npLyricsMode) updateLyricsHighlight(S.audio.currentTime * 1000);
   }
 }