agent: Add button to open thread as markdown (#28481)

<img
src="https://github.com/user-attachments/assets/92ca8f64-a949-4cc1-a657-3978a2c65839"
width="600"/>

Release Notes:

- agent: The action to open the current active thread in Markdown is now
exposed in the UI.
b46ab367efDanilo Leal committed on 4/10/2025, 3:09:34 AM· committed by GitHubparent12212dc
1 file changedLine totals unavailable