Function maybe_rerun_for_pending 

pub fn maybe_rerun_for_pending(
    state: Arc<AppState>,
    channel: &str,
    chat_id: i64,
    chat_type: &str,
)

Check if pending messages were queued during the last turn and spawn a new agent run to process them.

Channel adapters should call this after process_with_agent_with_events returns, passing the Arc<AppState> they already hold.