Function wrap_for_member 

pub fn wrap_for_member(
    zone_key: &ZoneKey,
    zone_name: &str,
    granter_seed: &[u8; 32],
    granter_verify_key: &PublicKey,
    recipient_verify_key: &PublicKey,
) -> String

Wrap a zone key for a recipient. The granter contributes their X25519 secret (derived from their identity seed); the recipient is addressed by their Ed25519 verify_key. Self-wrap is a special case where granter and recipient identify the same member.

Returns the hex-encoded wrap.