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/static/js/player.js

@@ -258,7 +258,7 @@ let visualizerCtx = null;
 let visualizerAnimFrame = null;
 let frequencyData = null;
 let smoothedFrequencies = null;
-const VISUALIZER_SMOOTHING = 0.65;
+const VISUALIZER_SMOOTHING = 0.15;
 
 async function checkVisualizerAvailability() {
     try {
@@ -386,7 +386,7 @@ function renderVisualizerFrame() {
     }
 
     const bass = frequencyData.bass || 0;
-    const scale = 1 + bass * 0.03;
+    const scale = 1 + bass * 0.04;
     const art = document.getElementById('album-art');
     if (art) {
         if (vinylMode) {
@@ -397,7 +397,7 @@ function renderVisualizerFrame() {
     }
     const glow = document.getElementById('album-art-glow');
     if (glow) {
-        glow.style.opacity = (0.5 + bass * 0.3).toFixed(2);
+        glow.style.opacity = (0.4 + bass * 0.4).toFixed(2);
     }
 }