* Add GCS storage backend with Workload Identity support
Register gocloud.dev/blob/gcsblob so gs:// URLs are accepted as a storage
backend. Authentication uses Application Default Credentials, which makes
GKE Workload Identity work out of the box; signed URLs (direct_serve)
fall back to the IAM Credentials signBlob API when no private key is
available.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* Replace gcsblob with lightweight GCS backend
* Extract GCS client into standalone module
---------
Co-authored-by: Anthony A. <github@anthony-arnaud.fr>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
