Address ai-review feedback on PR #17:
- Pin quay.io/minio/minio and mc to specific RELEASE tags (Renovate
will bump). 'latest' is unpredictable in GitOps.
- Bootstrap script: set -e -> set -euo pipefail.
- Postgres container: runAsNonRoot, uid/gid 999, drop ALL caps,
no privilege escalation. Matches PSS restricted profile.