{"alg":"Ed25519","public_key_hex":"a66800f6cfdc6d53d770945f037c95c80d2389b9562b5018a9ce4db076e3d1ec","signer_label":"did:hive:governance:sample-v1","signature_field":"mock_sig","signature_prefix_real":"0xsig:","signature_prefix_fallback":"0xmock:","verify_example":"GET /v1/receipts/verify/{seq}","note":"Field is named mock_sig for historical compatibility; production signatures use the 0xsig: prefix and are real Ed25519."}