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/api/setup.ts

@@ -0,0 +1,20 @@
+import client from './client';
+
+export interface SetupStatus {
+  setupRequired: boolean;
+}
+
+export interface SetupRequest {
+  name: string;
+  email: string;
+  password: string;
+}
+
+export const getSetupStatus = async (): Promise<SetupStatus> => {
+  const response = await client.get<SetupStatus>('/setup');
+  return response.data;
+};
+
+export const performSetup = async (data: SetupRequest): Promise<void> => {
+  await client.post('/setup', data);
+};