ORAS Artifact Manager

Stores archived build artifacts and stashes in an OCI registry using ORAS. Each Jenkins job is mapped to an OCI repository (its full name, sanitized), and each build's artifacts are anchored by a small "root" artifact tagged with the build number. Every archived file is pushed as its own single-layer artifact that refers back to the build's root artifact using the OCI 1.1 referrers mechanism, so the set of files archived for a build can be discovered with a single referrers API call.