Add UI animations: dialogs, tabs, settings, browser stagger, banner pulse

- Dialog modals: scale+fade entrance/exit with animated backdrop
- Tab panels: fade-in with subtle slide on switch
- Settings sections: content slide-down on expand
- Browser grid/list items: staggered cascade entrance animation
- Connection banner: slide-in + attention pulse on disconnect
- Accessibility: prefers-reduced-motion disables all animations

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

media_server/static/js/links.js

@@ -329,7 +329,7 @@ async function closeLinkDialog() {
 
     const dialog = document.getElementById('linkDialog');
     linkFormDirty = false;
-    dialog.close();
+    closeDialog(dialog);
     document.body.classList.remove('dialog-open');
 }