fix: TypeScript build errors in frontend pipeline

- Remove unused ReactNode import in useAuth.test.tsx
- Use vitest/config for defineConfig to recognize test property
- Add vitest/globals to tsconfig types for test runner globals

Frontend/src/hooks/__tests__/useAuth.test.tsx

@@ -1,7 +1,6 @@
 import { render, screen } from '@testing-library/react';
 import { AuthProvider } from '../useAuth';
 import { useAuth } from '../useAuth';
-import { ReactNode } from 'react';
 
 // Test component that uses useAuth hook
 const TestComponent = () => {