Function encrypt_message 

pub fn encrypt_message(
    bridge: &mut SignalBridge,
    peer: &str,
    plaintext: &[u8],
) -> Result<Vec<u8>, Box<dyn Error>>

Encrypts a message for a peer using Signal Protocol

Arguments

• bridge - Signal bridge instance
• peer - Recipient’s RDX fingerprint or Nostr pubkey
• plaintext - Message bytes to encrypt