Add an optional 'environment' field (default prod) and document sibling
.infra.dev.yaml manifests (same schema) so a project can declare a distinct
non-prod deployment — e.g. a local mac operator instance alongside the DO prod
service. Run-only/access config (passcodes, bind addrs) stays out of the manifest.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>