feat: Implement User Authentication and Fix Frontend Startup

- Implemented Issue #9: User Authentication & Authorization
  - Added User model fields (FailedLoginAttempts, LockedUntil, LastLogin)
  - Created AuthService with JWT support, bcrypt hashing, and account lockout
  - Added AuthMiddleware and AuthHandler
  - Registered auth routes in backend
  - Created AuthContext and RequireAuth component in frontend
  - Implemented Login page and integrated with backend
- Fixed 'Blank Page' issue in local Docker environment
  - Added QueryClientProvider to main.tsx
  - Installed missing lucide-react dependency
  - Fixed TypeScript linting errors in SetupGuard.tsx
- Updated docker-entrypoint.sh to use 127.0.0.1 for reliable Caddy checks
- Verified with local Docker build

frontend/src/pages/__tests__/Setup.test.tsx

@@ -0,0 +1,61 @@
+import { render, screen, waitFor } from '@testing-library/react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import { MemoryRouter } from 'react-router-dom';
+import { vi, describe, it, expect, beforeEach } from 'vitest';
+import Setup from '../Setup';
+import * as setupApi from '../../api/setup';
+
+// Mock the API module
+vi.mock('../../api/setup', () => ({
+  getSetupStatus: vi.fn(),
+  performSetup: vi.fn(),
+}));
+
+const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      retry: false,
+    },
+  },
+});
+
+const renderWithProviders = (ui: React.ReactNode) => {
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <MemoryRouter>
+        {ui}
+      </MemoryRouter>
+    </QueryClientProvider>
+  );
+};
+
+describe('Setup Page', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    queryClient.clear();
+  });
+
+  it('renders setup form when setup is required', async () => {
+    vi.mocked(setupApi.getSetupStatus).mockResolvedValue({ setupRequired: true });
+
+    renderWithProviders(<Setup />);
+
+    await waitFor(() => {
+      expect(screen.getByText('Welcome to CPM+')).toBeTruthy();
+    });
+
+    expect(screen.getByLabelText('Name')).toBeTruthy();
+    expect(screen.getByLabelText('Email Address')).toBeTruthy();
+    expect(screen.getByLabelText('Password')).toBeTruthy();
+  });
+
+  it('does not render form when setup is not required', async () => {
+    vi.mocked(setupApi.getSetupStatus).mockResolvedValue({ setupRequired: false });
+
+    renderWithProviders(<Setup />);
+
+    await waitFor(() => {
+      expect(screen.queryByText('Welcome to CPM+')).toBeNull();
+    });
+  });
+});