Function deliver_forwarded_broadcast 

pub(crate) async fn deliver_forwarded_broadcast(
    state: &AppState,
    block_id: &str,
    body: &str,
    msg_id: &str,
    recipients: usize,
) -> Result<(), String>

The receiving end of forward_broadcast_to_channel: builds the header here, from the target’s own agent id, and delivers it as any broadcast turn (BROADCAST_TURN_ORIGIN). Audited on this side too, naming where it came from.