Reduce visualizer latency, tighten UI paddings, fix mobile browser toolbar

- Visualizer: FPS 25→30, chunk_size 2048→1024, smoothing 0.65→0.15
- Beat effect: scale 0.03→0.04, glow range 0.5-0.8→0.4-0.8
- UI: reduce container/section paddings from 2rem to 1rem
- Source name: add ellipsis overflow for long names
- Mobile browser toolbar: use flex-wrap instead of column stack,
  hide "Items per page" label text on small screens

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

media_server/services/audio_analyzer.py

@@ -40,8 +40,8 @@ class AudioAnalyzer:
         self,
         num_bins: int = 32,
         sample_rate: int = 44100,
-        chunk_size: int = 2048,
-        target_fps: int = 25,
+        chunk_size: int = 1024,
+        target_fps: int = 30,
         device_name: str | None = None,
     ):
         self.num_bins = num_bins