fix(lyrics): improve LRCLIB lookup reliability

- Retry LRCLIB without album_name when exact match fails (404) —
  album name mismatch was the most common cause of falling back to plain
- Capture plainLyrics from LRCLIB and prefer it over Navidrome plain
  (LRCLIB plain text is usually higher quality)
- Use only first artist for LRCLIB lookup (multi-artist strings like
  'Artist A / Artist B' cause 404)

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

src/nowplaying.js

@@ -137,13 +137,26 @@ async function _loadNpLyrics(songId) {
     return;
   }
 
-  // 2. Fallback: fetch synced lyrics from LRCLIB
+  // 2. Fallback: fetch lyrics from LRCLIB
+  // Use only first artist (multi-artist strings like "A / B" break lookup)
+  const firstArtist = (s?.artist||'').split(/[/,]/)[0].trim();
   let lrcText = null;
+  let lrclibPlain = null;
   try {
-    const p = new URLSearchParams({ artist_name: s?.artist||'', track_name: s?.title||'' });
-    if(s?.album) p.set('album_name', s.album);
-    const r = await fetch(`https://lrclib.net/api/get?${p}`, { signal: AbortSignal.timeout(8000) });
-    if(r.ok) { const d = await r.json(); lrcText = d.syncedLyrics || null; }
+    // Try with album first, then without (album mismatch causes 404)
+    const attempts = [
+      new URLSearchParams({ artist_name: firstArtist, track_name: s?.title||'', ...(s?.album ? { album_name: s.album } : {}) }),
+      ...(s?.album ? [new URLSearchParams({ artist_name: firstArtist, track_name: s?.title||'' })] : []),
+    ];
+    for(const p of attempts) {
+      const r = await fetch(`https://lrclib.net/api/get?${p}`, { signal: AbortSignal.timeout(6000) });
+      if(r.ok) {
+        const d = await r.json();
+        lrcText = d.syncedLyrics || null;
+        lrclibPlain = d.plainLyrics || null;
+        break;
+      }
+    }
   } catch {}
 
   content.innerHTML = '';
@@ -152,10 +165,9 @@ async function _loadNpLyrics(songId) {
     if(parsed.length) { _renderSyncedLines(content, parsed); return; }
   }
 
-  // 3. Plain text fallback
-  const plain = track?.line?.length
-    ? track.line.map(l => l.value).join('\n')
-    : null;
+  // 3. Plain text — prefer LRCLIB plain over Navidrome plain (usually better quality)
+  const plain = lrclibPlain
+    || (track?.line?.length ? track.line.map(l => l.value).join('\n') : null);
   if(plain) {
     const el = document.createElement('div');
     el.className = 'lyrics-plain';