Result of initiating a PQXDH session (shared secret + ephemeral data).
Hex-encoded 32-byte shared secret.
Hex-encoded ephemeral X25519 public key (to send to responder).
Hex-encoded ML-KEM-768 ciphertext (to send to responder).
Algorithm identifier.
Result of initiating a PQXDH session (shared secret + ephemeral data).