feat: use simpler nitro instead of nestjs to implement mock service

apps/backend-mock/api/auth/login.post.ts

@@ -0,0 +1,20 @@
+export default defineEventHandler(async (event) => {
+  const { password, username } = await readBody(event);
+
+  const findUser = MOCK_USERS.find(
+    (item) => item.username === username && item.password === password,
+  );
+
+  if (!findUser) {
+    setResponseStatus(event, 403);
+    return useResponseError('UnauthorizedException', '用户名或密码错误');
+  }
+
+  const accessToken = Buffer.from(username).toString('base64');
+
+  return useResponseSuccess({
+    accessToken,
+    // TODO: refresh token
+    refreshToken: accessToken,
+  });
+});