Hybrid decapsulate — recovers the combined shared secret using our private keys and the sender's ephemeral data.
Our X25519 private key (hex).
Our ML-KEM secret key (hex).
Sender's ephemeral X25519 public key (hex).
ML-KEM ciphertext from the sender (hex).
Hybrid decapsulate — recovers the combined shared secret using our private keys and the sender's ephemeral data.