chore: demo page for system/department (#5611)

* feat: department management demo

* perf: department page improve

* feat: demo api middleware

* fix: add losing import

apps/backend-mock/middleware/1.api.ts

@@ -1,4 +1,6 @@
-export default defineEventHandler((event) => {
+import { forbiddenResponse, sleep } from '~/utils/response';
+
+export default defineEventHandler(async (event) => {
   event.node.res.setHeader(
     'Access-Control-Allow-Origin',
     event.headers.get('Origin') ?? '*',
@@ -7,5 +9,11 @@ export default defineEventHandler((event) => {
     event.node.res.statusCode = 204;
     event.node.res.statusMessage = 'No Content.';
     return 'OK';
+  } else if (
+    ['DELETE', 'PATCH', 'POST', 'PUT'].includes(event.method) &&
+    event.path.startsWith('/api/system/')
+  ) {
+    await sleep(Math.floor(Math.random() * 1000));
+    return forbiddenResponse(event, '演示环境，禁止修改');
   }
 });