Going for a different, arguably simpler design for the Assistant 2 empty
state here. Also took the opportunity to adjust other elements like the
toolbar, message editor, and some items in the configuration page.

<img
src="https://github.com/user-attachments/assets/03fd1d48-a675-4eac-b694-bbe4eeaf06e9"
width="700px"/>

Release Notes:

- N/A