member_identity_proof_invalid· reason_code· applies to event_envelope, state_resolutionThe MemberIdentity object carried by ak.member.identity.update failed proof validation: proof.payload_digest does not equal the sha256 of the proof-less MemberIdentity RFC 8785 JCS canonical bytes, the signature does not verify under proof.verification_method, or the method is not controlled by the disclosed subject_actor_id. The event MUST NOT be promoted to a verified display identity. See zh/sync/client-sync.md §8.1.