{"algorithm":"Ed25519","publicKeyHex":"0e1b40472f388090c765bfeb6c67b9eedbfeba7cfb194fdf47f5b2dc333251e6","purpose":"x402 Signed Freshness-Data Snapshot signing only (separate from the receive wallet's EVM key)","note":"Verify a data snapshot FREE at GET /v1/data/verify"}