Enhance backend configuration and error handling: Update CORS settings to allow dynamic origins, improve RabbitMQ connection handling in chat services, and adjust API server host configuration. Refactor environment variables for better flexibility and add fallback mechanisms for WebSocket and chat services. Update frontend environment files for consistent API and WebSocket URLs.

frontend/src/App.vue

@@ -1,8 +1,8 @@
 <template>
-  <div id="app">
-    <AppHeader />
-    <AppNavigation v-if="isLoggedIn && user.active" />
-    <AppContent />
+  <div id="app" class="app-shell">
+    <AppHeader class="app-shell__header" />
+    <AppNavigation v-if="isLoggedIn && user.active" class="app-shell__nav" />
+    <AppContent class="app-shell__content" />
     <AppFooter />
     <AnswerContact ref="answerContactDialog" />
     <RandomChatDialog ref="randomChatDialog" />
@@ -71,10 +71,10 @@ export default {
 </script>
 
 <style>
-#app {
+.app-shell {
   display: flex;
   flex-direction: column;
-  height: 100%;
+  height: 100vh;
   overflow: hidden;
 }
 </style>