[BUG] Headers rendering in Pieces TUI workstream activity

Check the difference between the headers in both screenshots. You can see that headers should have a bigger font size.

<img width="1919" height="1013" alt="Image" src="https://github.com/user-attachments/assets/267a1b3a-0660-41d4-b111-5ee7bb7d8e58" />

<img width="1919" height="1051" alt="Image" src="https://github.com/user-attachments/assets/13314264-60a8-4f94-a4ea-1d37e0c415fd" />