fix exam grading

src/api/rolePermission.ts

@@ -6,10 +6,14 @@ import { ApiHttpError, apiFetch } from './http'
 
 const BASE = '/api/v1/role-permission'
 
-function unwrapData<T>(body: T): T {
-  if (!body || typeof body !== 'object') return body
-  const maybeEnvelope = body as { data?: unknown }
-  return (maybeEnvelope.data as T | undefined) ?? body
+type DataEnvelope<T> = { data?: T }
+
+function unwrapData<T>(body: T | DataEnvelope<T>): T {
+  if (body && typeof body === 'object' && 'data' in body) {
+    const data = (body as DataEnvelope<T>).data
+    if (data !== undefined) return data
+  }
+  return body as T
 }
 
 export type RoleRow = {