Replace the one-shot minio-createbuckets service (which required a
manual 'abra app restart minio-createbuckets' that appeared to hang)
with a minio-initialize.sh config, ported from lasuite-docs. The minio
service entrypoint runs it in the background before starting minio; it
waits for minio to be ready and idempotently creates the
drive-media-storage bucket with versioning. Manual trigger:
'abra app cmd minio minio_initialize'.
Add a migrate.sh config (ported from lasuite-docs) that the backend
entrypoint runs when AUTO_MIGRATIONS=true (default). It loads secrets,
waits for the DB, and idempotently applies pending migrations via
'migrate --check' then 'migrate --noinput'. The manual 'abra app cmd
backend migrate' now delegates to the same script.
