This PR adds the total and per-file number of lines added and removed per thread, using the same logic to compute these as in the commit view. Here's how they show up in the UI: <img width="500" height="514" alt="Screenshot 2026-01-09 at 11 27@2x" src="https://github.com/user-attachments/assets/e3a4a14f-a4ee-4e95-a77b-86d14914e9d6" /> Release Notes: - Agent: Added the total and per-file number of lines added and removed in a thread.