fix: resolve multiple UI issues in player, playlist, lyrics, and queue

- Playlist: add console.error in catch block so load failures are visible
- Player: add progress bar with requestAnimationFrame and time display
- Player: extract toggleQueue function with debug logging for queue panel
- WebSocket: fetch queue on stateChange when not included in event payload
- Lyrics: use CSS transform scrolling and reduce sync to 500ms to fix flicker

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/src/views/Playlist.vue

@@ -96,8 +96,10 @@ onMounted(async () => {
     ]);
     playlist.value = detailRes.data.playlist;
     songs.value = songsRes.data.songs;
-  } catch {
-    // Ignore if API not ready
+  } catch (err) {
+    console.error('Failed to load playlist:', err);
+    playlist.value = null;
+    songs.value = [];
   } finally {
     loading.value = false;
   }