chore: add undici as explicit dependency for SSRF fix

Needed for the DNS-rebinding fix in connectors/fetch/client.js —
undici's Agent/fetch (a matching-version pair) is used to pin the
outbound connection to the pre-validated IP.

Author: allocsys

package.json

@@ -18,6 +18,7 @@
     "express": "^5.2.1",
     "express-rate-limit": "^8.6.1",
     "helmet": "^8.0.0",
+    "undici": "^8.9.0",
     "zod": "^4.4.3"
   },
   "devDependencies": {