Governance metadata in A2A Agent Cards, shipping the superset

A2A Agent Cards describe what an agent can do, where it lives, and how to talk to it. What they do not describe is governance posture. Two agents can hold identical cards and behave nothing alike in production. We shipped a reference implementation under extensions.asqav.governance inside the standard AgentCard envelope. Three fields carry the posture: trust_score , retention_ttl_seconds , and derivation_rights . Signed with the agent's own ML-DSA-65 keypair. Docs at asqav.com/docs/a2a . The sch