fix(frontend): resolve TS2352 type assertion error in API client

frontend/src/api/client.ts

@@ -92,7 +92,7 @@ apiClient.interceptors.response.use(
         response.data = apiResponse.data
       } else {
         // API error
-        const resp = apiResponse as Record<string, unknown>
+        const resp = apiResponse as unknown as Record<string, unknown>
         return Promise.reject({
           status: response.status,
           code: apiResponse.code,