Follow up to a regression that happened when we introduced agent servers
that made everywhere displaying agent names use the extension name
instead of the display name. This has been since fixed in other places
and this PR now updates the agent panel's message editor, too:

| Before | After |
|--------|--------|
| <img width="1154" height="254" alt="Screenshot 2025-12-18 at 12  54
2@2x"
src="https://github.com/user-attachments/assets/5f3de9f9-4e11-42f6-90c2-56fc8cdff32e"
/> | <img width="1154" height="254" alt="Screenshot 2025-12-18 at 12 
54@2x"
src="https://github.com/user-attachments/assets/46ed5c45-7e1d-4cc6-b219-b6cc19206d1b"
/> |

Release Notes:

- N/A