Function ask 

pub(crate) async fn ask(
    state: &AppState,
    block_id: &str,
    agent_id: &str,
    kind: Kind,
    payload: Value,
    timeout: Duration,
) -> Result<(Answer, Waiting), String>

Show payload in block_id’s banner and wait for the human, up to timeout. One request per pane at a time. The pane stays locked until the returned Waiting is dropped, so a caller that acts on a Yes holds it until that action is done.