Servarr MediaCover (posters/fanart) and backups currently live on each
replica's local /config, which is an emptyDir - so covers a leader downloads
are invisible to the other replicas behind the Service. Provision a shared S3
bucket to hold these assets instead.
- Add an arrstack-media ObjectStoreUser + Bucket (cephrgw-operator), mirroring
the CNPG backup pattern; the operator mints the arrstack-media-s3 credential
Secret in-namespace, so no Vault KV seeding is required.
- Wire the radarr Deployment to the bucket via Radarr__MediaCover__S3__* env
(creds from the operator Secret, estate CA mounted for RGW TLS). Unknown to
the current image and activated by the -unkin3+ MediaCover-S3 build; sonarr
and prowlarr wiring follow.