Fix admin reference mode regressions

frontend/vitest.setup.ts

@@ -0,0 +1,7 @@
+import { expect, vi } from 'vitest';
+import * as matchers from '@testing-library/jest-dom/matchers';
+
+expect.extend(matchers);
+
+// Provide Jest-compatible globals for existing tests that rely on jest.fn
+(globalThis as any).jest = vi;