✨(frontend) add visual permission indicator to device toggle button

Introduce accessible visual indicator on device toggle buttons to hint
when users have permission issues that require action.

Provides clear visual warning to help users understand they need to
resolve permissions before using camera/microphone features. Follows
accessibility guidelines for proper user guidance.

src/frontend/src/locales/nl/rooms.json

@@ -94,6 +94,10 @@
       }
     }
   },
+  "permissionsButton": {
+    "tooltip": "Meer info",
+    "ariaLabel": "Probleem met machtigingen. Meer info weergeven"
+  },
   "error": {
     "createRoom": {
       "heading": "Verificatie vereist",