ADR-A40: OCI reference export, restore, and command adapters

Status: Accepted Date: 2026-09-19 Supersedes: none Related: Phase 3, ADR-A31, release integration architecture

Context

The OCI reference adapter can package an Image Layout offline, but Phase 3 also requires portable export and restore evidence plus an integration route to established registry and signing tools. LATTICE must not embed ORAS or Cosign as semantic runtime dependencies.

Decision

Provide OciLayoutBundleService to copy an OCI layout as a portable bundle and verify its index.json digest before and after restore. Provide narrow CommandRunner-backed adapters for Cosign signing and ORAS registry transport. These adapters are invoked only by deployment configuration and can be replaced with other implementations of the same ports.

Consequences

• Offline fixture tests can prove export and restore integrity without a live registry.
• ORAS and Cosign commands, identity, keyless policy, registry namespace, and network behavior remain validation-environment concerns.
• A release stack remains responsible for promotion, rollback, retention enforcement, and deployment. LATTICE owns only semantic intent and evidence.