Banner content is clipped and inaccessible when Assistant window is docked or narrow

Steps to reproduce:

1. Create a Unity project
2. Click the "AI" button
3. Click "Agree and install Unity AI"
4. Wait until the installation is complete
5. Click the "AI" button and select "Open Assistant"
6. Expand "New in x.x.-pre.x section
7. Verify that all the info is easy to access and review
8. Dock this window next to the "Game" window
9. Try to review the same section 

Actual results: The text is cut off horizontally. Because the banner is a fixed UI element at the top, the user cannot scroll right to see the missing text, nor does the text wrap to a new line. 

Expected results: The UI should be responsive. Specifically:

• Text should word-wrap to fit the available width.

• Or, the banner should be part of a scrollable container.

Reproducible with versions: 2.6.0-pre.1(6000.6.0a3)

Tested on (OS): macOS - Tahoe 26.4.1