♻️ refactor(admin/areas): 重构区域管理API路由结构

- 将CRUD路由创建结果赋给变量areaRoutes
- 使用OpenAPIHono创建路由实例并合并treeRoutes和areaRoutes
- 优化路由组织方式，提高可维护性和扩展性

src/server/api/admin/areas/index.ts

@@ -8,9 +8,10 @@ import {
   areaListResponseSchema
 } from '@/server/modules/areas/area.schema';
 import treeRoutes from './tree';
+import { OpenAPIHono } from '@hono/zod-openapi';
 
 // 使用通用CRUD路由创建省市区管理API
-export default createCrudRoutes({
+const areaRoutes = createCrudRoutes({
   entity: AreaEntity,
   createSchema: createAreaSchema,
   updateSchema: updateAreaSchema,
@@ -21,6 +22,8 @@ export default createCrudRoutes({
   middleware: [authMiddleware]
 })
 
-// 合并树形结构路由
-.route('/', treeRoutes);
+export default new OpenAPIHono()
+  // 合并树形结构路由
+  .route('/', treeRoutes)
+  .route('/', areaRoutes);