The backup CronJob runs as uid 65532 (runAsNonRoot). mc defaulted its
config dir to $HOME/.mc = /.mc and failed with "mkdir /.mc: permission
denied" on the non-writable root fs — every nightly run died before
uploading, so there are currently no backups in s3://drops/_pgbackups/.
Point MC_CONFIG_DIR at the shared /work emptyDir (writable via fsGroup).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>