Steps to reproduce:
- Open Unity Editor with Dark Mode theme active (Preferences > General > Editor Theme)
- Open Preferences > AI > Assistant
- Scroll to "Checkpoint Settings" and observe the "Git LFS is not installed. Please install Git LFS to use checkpoints." warning box
Actual results: The warning box shows no icon in Dark Mode — only the red-bordered box and text remain, with no visual warning indicator beyond color.
Expected results: The warning box should show a warning icon (triangle with "!"), consistent with Light Mode and standard HelpBox warning styling.
Reproducible with versions: 2.17.0-pre.1 (6000.0.80f1, 6000.3.21f1, 6000.5.7f1, 6000.6.0b8, 6000.7.0a4)
Tested on (OS): MacBook Pro - Tahoe 26.5.2