- Remove automatic fullscreen setting from AutoInstallerGUI constructor
- Allow main() function to control fullscreen/windowed mode based on --no-fullscreen argument
- Fix logic: when --no-fullscreen is specified, use window.show() instead of fullscreen
- When --no-fullscreen is NOT specified, use window.showFullScreen() for production use
- Ensures command line argument properly controls the application's display mode

This resolves the issue where --no-fullscreen option was not working correctly
and allows proper testing in windowed mode while maintaining fullscreen for production.