fix(googlechat): harden google auth transport (#69812)

* fix(googlechat): localize google auth gaxios compat

* fix(googlechat): declare undici for staged runtime deps

* fix(googlechat): harden google auth transport

* fix(googlechat): narrow credential file reads

* fix(googlechat): preserve auth proxy transport

* fix(googlechat): allow symlinked auth files

* fix(googlechat): atomically load auth files

* fix(googlechat): eagerly buffer auth responses

* fix(googlechat): cap auth response buffering

* fix(googlechat): pin staged auth runtime deps

* fix(googlechat): buffer auth responses as array buffers

* Update CHANGELOG.md

* fix(googlechat): reject unstreamed auth responses

* fix(googlechat): use ambient fetch for auth transport

* fix(googlechat): keep guarded auth fetch on runtime path

* fix(googlechat): align staged zod range

* chore(lockfile): sync googlechat zod spec

package.json

@@ -1547,7 +1547,6 @@
     "dotenv": "^17.4.2",
     "express": "^5.2.1",
     "file-type": "22.0.1",
-    "gaxios": "7.1.4",
     "https-proxy-agent": "^9.0.0",
     "ipaddr.js": "^2.3.0",
     "jiti": "^2.6.1",