Define SourceOS State Integrity metadata for model artifacts

[mdheller]

Purpose

Model Carry should align model artifact inventory with the SourceOS State Integrity architecture.

Canonical spec: SourceOS-Linux/sourceos-spec/docs/architecture/sourceos-state-integrity-layer.md
Program tracker: SourceOS-Linux/sourceos-spec#83

Metadata fields

• artifact id
• content hash
• model provenance
• license metadata
• eval lineage
• hardware compatibility
• local availability
• remote reference availability
• profile id
• workspace id
• policy decision reference

Requirements

• Model artifacts should be represented as durable State Integrity objects.
• Large artifacts should support chunked or content-addressed references.
• Metadata must preserve provenance, license, eval, profile, and workspace context.
• Availability state should distinguish local, remote-reference, unavailable, restricted, and unknown.
• Derived indexes and previews should be rebuildable.

Acceptance criteria

• Model Carry defines an initial State Integrity metadata schema for model artifacts.
• Artifact metadata can be queried by profile, workspace, provenance, license, and availability state.
• Eval and license metadata survive inventory rebuilds.