assistant: Adjust slash command picker (#25920)

Mostly just fine-tuning its positioning. Other changes are mainly using
the Label's `buffer_font` method instead of using a div for that.

Release Notes:

- N/A
e0060b92ccDanilo Leal committed on 3/3/2025, 2:09:49 PM· committed by GitHubparent06bcc42
1 file changedLine totals unavailable