Fix: debounce theme-refresh 300ms — no more re-render spam

Color picker input events fire dozens of times per second while
dragging. Now debounced to 300ms — page re-renders once after
you stop dragging.

public/app.js

@@ -315,9 +315,13 @@ function navigate() {
 }
 
 window.addEventListener('hashchange', navigate);
+let _themeRefreshTimer = null;
 window.addEventListener('theme-changed', () => {
-  // Notify current page to re-render without full teardown
-  window.dispatchEvent(new CustomEvent('theme-refresh'));
+  if (_themeRefreshTimer) clearTimeout(_themeRefreshTimer);
+  _themeRefreshTimer = setTimeout(() => {
+    _themeRefreshTimer = null;
+    window.dispatchEvent(new CustomEvent('theme-refresh'));
+  }, 300);
 });
 window.addEventListener('DOMContentLoaded', () => {
   connectWS();

public/index.html

@@ -85,7 +85,7 @@
   <script src="region-filter.js?v=1774325000"></script>
   <script src="hop-resolver.js?v=1774223973"></script>
   <script src="hop-display.js?v=1774221932"></script>
-  <script src="app.js?v=1774231586"></script>
+  <script src="app.js?v=1774234100"></script>
   <script src="home.js?v=1774233807"></script>
   <script src="packets.js?v=1774231586"></script>
   <script src="map.js?v=1774231586" onerror="console.error('Failed to load:', this.src)"></script>