fix: progress bar smooth via rAF with direct Date.now(), queue panel moved outside player div

- Progress bar reads playStartedAt directly in requestAnimationFrame loop
  bypassing Vue reactivity caching for smooth 60fps updates
- Queue panel moved to sibling of player-bar (was trapped inside causing z-index issues)
- Added progress thumb dot on hover
- Click on progress shows 'seek not available' tooltip

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

web/src/views/Playlist.vue

@@ -96,8 +96,8 @@ onMounted(async () => {
     ]);
     playlist.value = detailRes.data.playlist;
     songs.value = songsRes.data.songs;
-  } catch (err) {
-    console.error('Failed to load playlist:', err);
+  } catch (err: any) {
+    console.error('Failed to load playlist:', err?.response?.status, err?.message);
     playlist.value = null;
     songs.value = [];
   } finally {