UI: hide aspect ratio inputText if custom aspect ratio is unselected

1. inputText should be hidden (conditional) if custom aspect ratio is not selected
2. Please also remove unneeded CamelCase:  change 'Custom Aspect Ratio' to 'Custom aspect ratio'
3. Remove second 'Aspect Ratio'  (unneeded repetition)

<img width="736" height="728" alt="Image" src="https://github.com/user-attachments/assets/9003a593-9a1d-45ed-ad4b-a67e4e2633f1" />