The lint-docker-compose workflow was swallowing all validation errors with
|| true, meaning broken compose files would never fail the check.
- Remove || true and let validation failures propagate
- Add a pre-step that creates empty stubs for referenced env_file entries
(e.g. bitwarden/settings.env) so docker compose config can validate
structure without needing real secrets
- Track per-file pass/fail and exit non-zero if any file fails
Closes PESO-130
