fix: Configure admin service URLs dynamically based on environment

- Update adminService to fetch server URL from /api/config endpoint
- Initialize server URL before making any API calls
- Make connect() method async to handle URL initialization
- Update Vue component to await adminService.connect()
- Resolves hardcoded localhost URLs in production environment

admin/src/App.vue

@@ -129,7 +129,7 @@ onMounted(async () => {
     serverUrl.value = config.serverUrl
 
     // Connect to SSE
-    adminService.connect((data) => {
+    await adminService.connect((data) => {
       if (data.type === 'connected') {
         isConnected.value = true
       } else if (data.type === 'gameStats') {