Function establish_session 

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

Establishes a Signal Protocol session from a prekey bundle

Arguments

• bridge - Signal bridge instance
• peer - Peer’s RDX fingerprint or Nostr pubkey
• bundle - Serialized prekey bundle bytes