interface SessionKeys {
  /** Ed25519 public key shared with clients for signing verification */
  publicKey: string;
  /** Ed25519 private key - RAM-only, never persisted */
  privateKey: string;
  /** X25519 public key for ECDH key agreement (encryption) */
  x25519PublicKey: string;
  /** X25519 private key - RAM-only, never persisted */
  x25519PrivateKey: string;
  /** When the keys were created */
  createdAt: number;
}