fix: downgrade express and @types/express to compatible versions (#119)

package.json

@@ -44,7 +44,7 @@
     "@modelcontextprotocol/sdk": "^1.11.1",
     "bcryptjs": "^3.0.2",
     "dotenv": "^16.3.1",
-    "express": "^5.1.0",
+    "express": "^4.21.2",
     "express-validator": "^7.2.1",
     "jsonwebtoken": "^9.0.2",
     "uuid": "^11.1.0"
@@ -56,7 +56,7 @@
     "@tailwindcss/postcss": "^4.1.3",
     "@tailwindcss/vite": "^4.1.7",
     "@types/bcryptjs": "^3.0.0",
-    "@types/express": "^5.0.2",
+    "@types/express": "^4.17.21",
     "@types/jest": "^29.5.5",
     "@types/jsonwebtoken": "^9.0.9",
     "@types/node": "^22.15.21",