feat: add metadata schema configuration UI [AC-IDSMETA-13]

- Add metadata-schemas route and navigation menu item
- Add metadata schema list page with status filter
- Add metadata schema create/edit dialog
- Add metadata schema API service and types

ai-service-admin/src/App.vue

@@ -54,6 +54,10 @@
             <el-icon><Warning /></el-icon>
             <span>输出护栏</span>
           </router-link>
+          <router-link to="/admin/metadata-schemas" class="nav-item" :class="{ active: isActive('/admin/metadata-schemas') }">
+            <el-icon><Setting /></el-icon>
+            <span>元数据配置</span>
+          </router-link>
         </nav>
       </div>
       <div class="header-right">
@@ -86,7 +90,7 @@ import { ref, onMounted } from 'vue'
 import { useRoute } from 'vue-router'
 import { useTenantStore } from '@/stores/tenant'
 import { getTenantList, type Tenant } from '@/api/tenant'
-import { Odometer, FolderOpened, Cpu, Monitor, Connection, ChatDotSquare, Document, Aim, Share, Warning } from '@element-plus/icons-vue'
+import { Odometer, FolderOpened, Cpu, Monitor, Connection, ChatDotSquare, Document, Aim, Share, Warning, Setting } from '@element-plus/icons-vue'
 import { ElMessage } from 'element-plus'
 
 const route = useRoute()