sidebar: Improve project header truncation (#51096)

Touching up the scenario in which the project header label is too big.
This uses the same gradient overlay treatment we're using for the thread
item component.

Release Notes:

- N/A
26f81c4818Danilo Leal committed on 3/9/2026, 1:03:15 PM· committed by GitHubparent0924bb8
3 files changedLine totals unavailable