fix: bust browser cache for app.js to force reload of updated script

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

frontend/index.html

@@ -735,6 +735,6 @@
 
     <script src="/app/vue.global.prod.js"></script>
     <script src="/app/bootstrap.bundle.min.js"></script>
-    <script src="/app/app.js" defer></script>
+    <script src="/app/app.js?v=2" defer></script>
   </body>
   </html>