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.

backend/package.json

@@ -15,14 +15,19 @@
         "cors": "^2.8.5",
         "dotenv": "^16.4.5",
         "express": "^4.21.1",
-        "mysql2": "^3.11.3"
+        "express-rate-limit": "^8.2.1",
+        "express-slow-down": "^3.0.1",
+        "helmet": "^8.1.0",
+        "mysql2": "^3.11.3",
+        "nodemailer": "^8.0.1"
     },
     "devDependencies": {
         "@types/cors": "^2.8.17",
         "@types/express": "^5.0.0",
         "@types/node": "^22.8.6",
+        "@types/nodemailer": "^7.0.11",
         "nodemon": "^3.1.7",
         "ts-node": "^10.9.2",
         "typescript": "^5.6.3"
     }
-}
+}