Method cancel

crates/opencode-session/src/prompt.rs:757–765

(&self, session_id: &str)

    }

    pub async fn cancel(&self, session_id: &str) {
        let mut state = self.state.lock().await;
        if let Some(prompt_state) = state.remove(session_id) {
            prompt_state.cancel_token.cancel();
        }

        let mut session_state = self.session_state.write().await;
        session_state.set_idle(session_id);
    }

    pub async fn prompt(
        &self,