Update Web UI: Improve volume slider responsiveness

- Add real-time volume updates while dragging slider
- Throttle updates to 50ms for smooth, responsive feedback
- Prevent overwhelming server with excessive API calls
- Update volume immediately on mouse release for final value

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

media_server/static/index.html

@@ -1395,6 +1395,7 @@
         let currentDuration = 0;
         let currentPosition = 0;
         let isUserAdjustingVolume = false;
+        let volumeUpdateTimer = null;  // Timer for throttling volume updates
         let scripts = [];
         let lastStatus = null;  // Store last status for locale switching
 
@@ -1431,9 +1432,25 @@
                 isUserAdjustingVolume = true;
                 const volume = parseInt(e.target.value);
                 document.getElementById('volume-display').textContent = `${volume}%`;
+
+                // Throttle volume updates while dragging (update every 50ms)
+                if (volumeUpdateTimer) {
+                    clearTimeout(volumeUpdateTimer);
+                }
+                volumeUpdateTimer = setTimeout(() => {
+                    setVolume(volume);
+                    volumeUpdateTimer = null;
+                }, 50);
             });
 
             volumeSlider.addEventListener('change', (e) => {
+                // Clear any pending throttled update
+                if (volumeUpdateTimer) {
+                    clearTimeout(volumeUpdateTimer);
+                    volumeUpdateTimer = null;
+                }
+
+                // Send final volume update immediately
                 const volume = parseInt(e.target.value);
                 setVolume(volume);
                 setTimeout(() => { isUserAdjustingVolume = false; }, 500);