Add tests for useAuth hooks and AuthGuard component; Update .gitignore

- Implemented comprehensive tests for `useAuth` hooks (`useIsAuthenticated`, `useCurrentUser`, and `useIsAdmin`) with mock states and coverage for edge cases.
- Added tests for `AuthGuard` to validate route protection, admin access control, loading states, and use of fallback components.
- Updated `.gitignore` to exclude `coverage.json`.

frontend/tests/lib/api/hooks/useAuth.test.tsx

@@ -0,0 +1,222 @@
+/**
+ * Tests for useAuth hooks
+ * Note: Full API integration tests require MSW (planned for Phase 9)
+ * These tests cover hook setup, types, and basic integration
+ */
+
+import { renderHook, waitFor } from '@testing-library/react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import {
+  useIsAuthenticated,
+  useCurrentUser,
+  useIsAdmin,
+} from '@/lib/api/hooks/useAuth';
+
+// Mock auth store
+let mockAuthState: {
+  isAuthenticated: boolean;
+  user: any;
+  accessToken: string | null;
+  refreshToken: string | null;
+} = {
+  isAuthenticated: false,
+  user: null,
+  accessToken: null,
+  refreshToken: null,
+};
+
+jest.mock('@/stores/authStore', () => ({
+  useAuthStore: (selector?: (state: any) => any) => {
+    if (selector) {
+      return selector(mockAuthState);
+    }
+    return mockAuthState;
+  },
+}));
+
+// Mock router
+jest.mock('next/navigation', () => ({
+  useRouter: () => ({
+    push: jest.fn(),
+  }),
+}));
+
+const createWrapper = () => {
+  const queryClient = new QueryClient({
+    defaultOptions: {
+      queries: { retry: false },
+      mutations: { retry: false },
+    },
+  });
+
+  return ({ children }: { children: React.ReactNode }) => (
+    <QueryClientProvider client={queryClient}>
+      {children}
+    </QueryClientProvider>
+  );
+};
+
+describe('useAuth Hooks', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockAuthState = {
+      isAuthenticated: false,
+      user: null,
+      accessToken: null,
+      refreshToken: null,
+    };
+  });
+
+  describe('useIsAuthenticated', () => {
+    it('returns false when not authenticated', () => {
+      mockAuthState = {
+        isAuthenticated: false,
+        user: null,
+        accessToken: null,
+        refreshToken: null,
+      };
+
+      const { result } = renderHook(() => useIsAuthenticated(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBe(false);
+    });
+
+    it('returns true when authenticated', () => {
+      mockAuthState = {
+        isAuthenticated: true,
+        user: {
+          id: '1',
+          email: 'user@example.com',
+          first_name: 'Test',
+          last_name: 'User',
+          is_active: true,
+          is_superuser: false,
+          created_at: '2024-01-01',
+          updated_at: '2024-01-01',
+        },
+        accessToken: 'test-token',
+        refreshToken: 'test-refresh',
+      };
+
+      const { result } = renderHook(() => useIsAuthenticated(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBe(true);
+    });
+  });
+
+  describe('useCurrentUser', () => {
+    it('returns null when not authenticated', () => {
+      mockAuthState = {
+        isAuthenticated: false,
+        user: null,
+        accessToken: null,
+        refreshToken: null,
+      };
+
+      const { result } = renderHook(() => useCurrentUser(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBeNull();
+    });
+
+    it('returns user when authenticated', () => {
+      const mockUser = {
+        id: '1',
+        email: 'user@example.com',
+        first_name: 'Test',
+        last_name: 'User',
+        is_active: true,
+        is_superuser: false,
+        created_at: '2024-01-01',
+        updated_at: '2024-01-01',
+      };
+
+      mockAuthState = {
+        isAuthenticated: true,
+        user: mockUser,
+        accessToken: 'test-token',
+        refreshToken: 'test-refresh',
+      };
+
+      const { result } = renderHook(() => useCurrentUser(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toEqual(mockUser);
+    });
+  });
+
+  describe('useIsAdmin', () => {
+    it('returns false when not authenticated', () => {
+      mockAuthState = {
+        isAuthenticated: false,
+        user: null,
+        accessToken: null,
+        refreshToken: null,
+      };
+
+      const { result } = renderHook(() => useIsAdmin(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBe(false);
+    });
+
+    it('returns false for regular user', () => {
+      mockAuthState = {
+        isAuthenticated: true,
+        user: {
+          id: '1',
+          email: 'user@example.com',
+          first_name: 'Test',
+          last_name: 'User',
+          is_active: true,
+          is_superuser: false,
+          created_at: '2024-01-01',
+          updated_at: '2024-01-01',
+        },
+        accessToken: 'test-token',
+        refreshToken: 'test-refresh',
+      };
+
+      const { result } = renderHook(() => useIsAdmin(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBe(false);
+    });
+
+    it('returns true for admin user', () => {
+      mockAuthState = {
+        isAuthenticated: true,
+        user: {
+          id: '1',
+          email: 'admin@example.com',
+          first_name: 'Admin',
+          last_name: 'User',
+          is_active: true,
+          is_superuser: true,
+          created_at: '2024-01-01',
+          updated_at: '2024-01-01',
+        },
+        accessToken: 'test-token',
+        refreshToken: 'test-refresh',
+      };
+
+      const { result } = renderHook(() => useIsAdmin(), {
+        wrapper: createWrapper(),
+      });
+
+      expect(result.current).toBe(true);
+    });
+  });
+
+  // Note: Mutation hooks (useLogin, useRegister, etc.) require MSW for full testing
+  // These will be tested in Phase 9 with proper API mocking
+  // For now, we've tested the convenience hooks which improve coverage significantly
+});