feat: add profile setup, verification, and authentication context

- Implement ProfileSetup component for user profile creation with username validation.
- Create ProtectedRoute component to guard routes based on authentication status.
- Add VerifyAuthCode component for email verification with resend functionality.
- Establish AuthContext for managing user authentication state and actions.
- Enhance CookieContext for consent management with server-side verification.
- Set up Firebase configuration for authentication and analytics.
- Update styles for authentication components and header layout.
- Configure Vite proxy for API requests during development.

frontend/package.json

@@ -12,6 +12,7 @@
   "dependencies": {
     "@emailjs/browser": "^4.4.1",
     "axios": "^1.13.2",
+    "firebase": "^12.9.0",
     "framer-motion": "^12.23.24",
     "lucide-react": "^0.553.0",
     "react": "^19.2.0",