protect against sql injection, xss, csrf

backend/package.json

@@ -19,11 +19,17 @@
     "@googlemaps/google-maps-services-js": "^3.4.2",
     "bcryptjs": "^3.0.2",
     "body-parser": "^2.2.0",
+    "cookie-parser": "^1.4.7",
     "cors": "^2.8.5",
+    "csrf": "^3.1.0",
+    "dompurify": "^3.2.6",
     "dotenv": "^17.2.0",
     "express": "^5.1.0",
     "express-rate-limit": "^8.1.0",
+    "express-validator": "^7.2.1",
     "google-auth-library": "^10.3.0",
+    "helmet": "^8.1.0",
+    "jsdom": "^27.0.0",
     "jsonwebtoken": "^9.0.2",
     "multer": "^2.0.2",
     "node-cron": "^3.0.3",