AxUCPHTTPMessageSignatureErrorCode
type AxUCPHTTPMessageSignatureErrorCode =
| "signature_missing"
| "signature_invalid"
| "key_not_found"
| "digest_mismatch"
| "algorithm_unsupported"
| "signature_expired"
| "signature_replayed";Defined in: https://github.com/ax-llm/ax/blob/686f8ba96cf652e044cf922b67c16c8f09754a70/src/ax/ucp/signing.ts#L26