feat: migrate from Element Plus to Ant Design Vue and update Vite configuration for better dependency management

- Updated Vite configuration to manually chunk Ant Design Vue for improved dependency management.
- Added a comprehensive migration testing checklist for transitioning from Element Plus 2.13.0 to Ant Design Vue 4.x, covering various components and functionalities.

frontend/src/components/Layout.vue

@@ -8,21 +8,30 @@
 </template>
 
 <script setup>
+import { onMounted } from 'vue'
 import Navbar from './Navbar.vue'
+import { useTokenMonitor } from '@/composables/useTokenMonitor'
+
+// 启动全局 Token 监控
+const { startMonitoring } = useTokenMonitor()
+
+onMounted(() => {
+  startMonitoring()
+})
 </script>
 
 <style scoped>
 .layout-container {
   width: 100%;
-  height: 100%;
+  min-height: 100vh;
   display: flex;
   flex-direction: column;
+  background: linear-gradient(135deg, #f5f7fa 0%, #e8eef5 100%);
 }
 
 .main-content {
   flex: 1;
   overflow-y: auto;
-  background-color: #f5f5f5;
   padding: 20px;
 }
 </style>