Added option to summarize the chat when an error is triggered

[zanesq]

Added option to summarize the chat when an error is triggered

[michaelneale]

not sure how to manually test it - but reads well. Am trying to run it locally now (but taking a while).

[zanesq]

When testing locally I would temporarily force an error from the backend, code like this in reply.rs

    // TEMPORARY: Trigger error after 2 messages for testing auto-summarize feature
    // This gives us some conversation history to actually summarize
    if messages.len() >= 2 && messages.iter().filter(|m| m.role == rmcp::model::Role::User).count() >= 2 {
        let (tx, rx) = mpsc::channel(100);
        let stream = ReceiverStream::new(rx);

        tokio::spawn(async move {
            let _ = stream_event(
                MessageEvent::Error {
                    error: "Temporary test error - this is a simulated backend error for testing the auto-summarize feature".to_string(),
                },
                &tx,
            ).await;
        });

        return Ok(SseResponse::new(stream));
    }

[michaelneale]

yeah looks good