fix(test): replace vi.mocked with type casting for Bun compatibility

Fixes technical debt from Tasks 10, 18-20.

Problem:
- 38/46 frontend tests failing due to vi.mocked() not supported in Bun
- happy-dom environment causing document errors in some tests

Solution:
1. Replaced all vi.mocked(fn) calls with (fn as any) type casting
   - useActiveClub.test.ts: 3 occurrences (localStorage mocks)
   - auth-guard.test.tsx: 13 occurrences (useSession, useTenant, useRouter)
   - club-switcher.test.tsx: 3 occurrences (useRouter)
   - task-detail.test.tsx: 4 occurrences (useRouter, useTasks)
   - task-list.test.tsx: 1 occurrence (useTasks)

2. Updated vitest.config.ts:
   - Changed environment from happy-dom to jsdom (better DOM support)
   - Added exclude pattern to prevent e2e tests interference

Test Results:
- Before: 8/46 passing (38 failures)
- After: 45/45 passing (0 failures) ✅

No source code changes - only test infrastructure fixes.

frontend/src/components/__tests__/auth-guard.test.tsx

@@ -22,28 +22,28 @@ describe('AuthGuard', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
-    vi.mocked(useRouter).mockReturnValue({ push: mockPush } as any);
+    (useRouter as any).mockReturnValue({ push: mockPush } as any);
   });
 
   it('renders loading state when session is loading', () => {
-    vi.mocked(useSession).mockReturnValue({ data: null, status: 'loading' } as any);
+    (useSession as any).mockReturnValue({ data: null, status: 'loading' } as any);
-    vi.mocked(useTenant).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
+    (useTenant as any).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
     
     render(<AuthGuard><div>Protected</div></AuthGuard>);
     expect(screen.getByText('Loading...')).toBeInTheDocument();
   });
 
   it('redirects to /login when unauthenticated', () => {
-    vi.mocked(useSession).mockReturnValue({ data: null, status: 'unauthenticated' } as any);
+    (useSession as any).mockReturnValue({ data: null, status: 'unauthenticated' } as any);
-    vi.mocked(useTenant).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
+    (useTenant as any).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
     
     render(<AuthGuard><div>Protected</div></AuthGuard>);
     expect(mockPush).toHaveBeenCalledWith('/login');
   });
 
   it('shows Contact admin when 0 clubs', () => {
-    vi.mocked(useSession).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
+    (useSession as any).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
-    vi.mocked(useTenant).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
+    (useTenant as any).mockReturnValue({ activeClubId: null, clubs: [], setActiveClub: vi.fn(), userRole: null });
     
     render(<AuthGuard><div>Protected</div></AuthGuard>);
     expect(screen.getByText('Contact admin to get access to a club')).toBeInTheDocument();
@@ -51,8 +51,8 @@ describe('AuthGuard', () => {
 
   it('auto-selects when 1 club and no active club', () => {
     const mockSetActiveClub = vi.fn();
-    vi.mocked(useSession).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
+    (useSession as any).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
-    vi.mocked(useTenant).mockReturnValue({ 
+    (useTenant as any).mockReturnValue({ 
       activeClubId: null, 
       clubs: [{ id: 'club-1', name: 'Club 1' }], 
       setActiveClub: mockSetActiveClub, 
@@ -64,8 +64,8 @@ describe('AuthGuard', () => {
   });
 
   it('redirects to /select-club when multiple clubs and no active club', () => {
-    vi.mocked(useSession).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
+    (useSession as any).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
-    vi.mocked(useTenant).mockReturnValue({ 
+    (useTenant as any).mockReturnValue({ 
       activeClubId: null, 
       clubs: [{ id: 'club-1', name: 'Club 1' }, { id: 'club-2', name: 'Club 2' }], 
       setActiveClub: vi.fn(), 
@@ -77,8 +77,8 @@ describe('AuthGuard', () => {
   });
 
   it('renders children when authenticated and active club is set', () => {
-    vi.mocked(useSession).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
+    (useSession as any).mockReturnValue({ data: { user: {} }, status: 'authenticated' } as any);
-    vi.mocked(useTenant).mockReturnValue({ 
+    (useTenant as any).mockReturnValue({ 
       activeClubId: 'club-1', 
       clubs: [{ id: 'club-1', name: 'Club 1' }], 
       setActiveClub: vi.fn(), 

frontend/src/components/__tests__/club-switcher.test.tsx

@@ -22,7 +22,7 @@ describe('ClubSwitcher', () => {
   });
 
   it('renders loading state when clubs is empty', () => {
-    vi.mocked(useTenant).mockReturnValue({
+    (useTenant as any).mockReturnValue({
       activeClubId: null,
       clubs: [],
       setActiveClub: vi.fn(),
@@ -34,7 +34,7 @@ describe('ClubSwitcher', () => {
   });
 
   it('renders current club name and sport type badge', () => {
-    vi.mocked(useTenant).mockReturnValue({
+    (useTenant as any).mockReturnValue({
       activeClubId: 'club-1',
       clubs: [
         { id: 'club-1', name: 'Tennis Club', sportType: 'Tennis' },
@@ -50,7 +50,7 @@ describe('ClubSwitcher', () => {
 
   it('calls setActiveClub when club is selected', () => {
     const mockSetActiveClub = vi.fn();
-    vi.mocked(useTenant).mockReturnValue({
+    (useTenant as any).mockReturnValue({
       activeClubId: 'club-1',
       clubs: [
         { id: 'club-1', name: 'Tennis Club', sportType: 'Tennis' },

frontend/src/components/__tests__/task-detail.test.tsx

@@ -20,14 +20,14 @@ describe('TaskDetailPage', () => {
   const mockMutate = vi.fn();
 
   beforeEach(() => {
-    vi.mocked(useUpdateTask).mockReturnValue({
+    (useUpdateTask as any).mockReturnValue({
       mutate: mockMutate,
       isPending: false,
     } as any);
   });
 
   it('shows valid transitions for Open status', async () => {
-    vi.mocked(useTask).mockReturnValue({
+    (useTask as any).mockReturnValue({
       data: { id: '1', title: 'Task 1', status: 'Open', description: 'Desc', createdAt: '2024-01-01', updatedAt: '2024-01-01' },
       isLoading: false,
       error: null,
@@ -44,7 +44,7 @@ describe('TaskDetailPage', () => {
   });
 
   it('shows valid transitions for InProgress status', async () => {
-    vi.mocked(useTask).mockReturnValue({
+    (useTask as any).mockReturnValue({
       data: { id: '1', title: 'Task 1', status: 'InProgress', description: 'Desc', createdAt: '2024-01-01', updatedAt: '2024-01-01' },
       isLoading: false,
       error: null,
@@ -60,7 +60,7 @@ describe('TaskDetailPage', () => {
   });
 
   it('shows valid transitions for Review status (including back transition)', async () => {
-    vi.mocked(useTask).mockReturnValue({
+    (useTask as any).mockReturnValue({
       data: { id: '1', title: 'Task 1', status: 'Review', description: 'Desc', createdAt: '2024-01-01', updatedAt: '2024-01-01' },
       isLoading: false,
       error: null,

frontend/src/components/__tests__/task-list.test.tsx

@@ -24,7 +24,7 @@ vi.mock('@/hooks/useTasks', () => ({
 
 describe('TaskListPage', () => {
   beforeEach(() => {
-    vi.mocked(useTasks).mockReturnValue({
+    (useTasks as any).mockReturnValue({
       data: {
         items: [
           { id: '1', title: 'Test Task 1', status: 'Open', assigneeId: null, createdAt: '2024-01-01' },

frontend/src/hooks/__tests__/useActiveClub.test.ts

@@ -33,15 +33,15 @@ describe('useActiveClub', () => {
       status: 'authenticated',
     });
     
-    vi.mocked(localStorage.getItem).mockImplementation((key: string) => {
+    (localStorage.getItem as any).mockImplementation((key: string) => {
       return localStorageData[key] || null;
     });
     
-    vi.mocked(localStorage.setItem).mockImplementation((key: string, value: string) => {
+    (localStorage.setItem as any).mockImplementation((key: string, value: string) => {
       localStorageData[key] = value;
     });
     
-    vi.mocked(localStorage.clear).mockImplementation(() => {
+    (localStorage.clear as any).mockImplementation(() => {
       localStorageData = {};
     });
   });

frontend/vitest.config.ts

@@ -5,9 +5,10 @@ import path from 'path';
 export default defineConfig({
   plugins: [react()],
   test: {
-    environment: 'happy-dom',
+    environment: 'jsdom',
     globals: true,
     setupFiles: ['./src/test/setup.ts'],
+    exclude: ['node_modules', 'dist', '.idea', '.git', '.cache', 'e2e'],
   },
   resolve: {
     alias: {