assistant2: Add stray visual adjusments (#22386)

This PR adds just some tiny visual clean ups to the assistant2 panel.
Nothing major, honestly.

<img width="800" alt="Screenshot 2024-12-24 at 12 19 46 AM"
src="https://github.com/user-attachments/assets/da22aa7f-8a42-4ff0-9e4c-5e8b60b28802"
/>

Release Notes:

- N/A