chore: Vendor request-filtering-agent (#12266)

* chore: Vendor request-filtering-agent

* fix: honor fetch timeout and undefined allow list in proxy pre-flight

Default allowIPAddressList to [] so an unset ALLOWED_PRIVATE_IP_ADDRESSES
env var doesn't overwrite the agent's default and crash on .length, and
race the pre-flight DNS lookup against the request's abort signal so the
configured fetch timeout applies to slow DNS resolution.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

package.json

@@ -231,7 +231,6 @@
     "redlock": "^5.0.0-beta2",
     "reflect-metadata": "^0.2.2",
     "refractor": "^3.6.0",
-    "request-filtering-agent": "^3.2.0",
     "resolve-path": "^1.4.0",
     "sanitize-filename": "^1.6.4",
     "scroll-into-view-if-needed": "^3.1.0",