How to reproduce:
1. Create a new Unity project
2. In the Unity toolbar, click the three-dot menu -> Presets -> Save Preset
3. Enter the space at the end of the default name
3. Observe the results
Expected results: A trailing space is either trimmed automatically or accepted as a valid character, and the Create button remains enabled
Actual results: "Preset Name has unsupported characters" error is shown and the Create button is disabled
Reproducible with: 6000.4.0a3, 6000.6.2f1, 6000.7.0a6
Not reproducible with: 6000.3.17f1, 6000.4.0a2
Reproducible on: macOS Tahoe 26 (M1)
Not reproducible on: No other environment tested