Function ed25519PubToX25519

ed25519PubToX25519(edPublicKey: Uint8Array): Uint8Array
Converts an Ed25519 PUBLIC key to its X25519 (Montgomery) form.

Used in X3DH to convert the recipient's identity public key (Ed25519) to X25519 for ECDH operations. Uses @noble/curves ed25519.utils.toMontgomery() which accepts both private and public keys.
Parameters
- edPublicKey: Uint8Array
  32-byte Ed25519 public key.
Returns Uint8Array
32-byte X25519 public key.
Throws
'INVALID_LENGTH' if input ≠ 32B.
Example
```
const xPub = ed25519PubToX25519(edPubKey);
const shared = x25519SharedSecret(ephemeralPriv, xPub);
```
- Defined in packages/crypto/src/core/ecdh.ts:116