c2pa-sign

Embed C2PA provenance manifests in AI-generated assets — the machine-readable AI disclosure EU AI Act Article 50 expects (enforceable since 2 Aug 2026), plus the human-approval record for the Article 50(4) exemption. Triggers on "/c2pa-sign", "sign this asset", "provenance", "content credentials", "AI disclosure", "Article 50", "is this compliant to publish", or before any AI-generated asset ships. Pass --reviewed-by and --model-id so the manifest records who approved it and what made it.