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

apps/backend-mock/api/auth/codes.ts

@@ -0,0 +1,15 @@
+export default eventHandler((event) => {
+  const token = getHeader(event, 'Authorization');
+
+  if (!token) {
+    setResponseStatus(event, 401);
+    return useResponseError('UnauthorizedException', 'Unauthorized Exception');
+  }
+
+  const username = Buffer.from(token, 'base64').toString('utf8');
+
+  const codes =
+    MOCK_CODES.find((item) => item.username === username)?.codes ?? [];
+
+  return useResponseSuccess(codes);
+});