[macOS] mlterm does not handle spaces in paths if a file is drag-n-dropped into it

@arakiken Hi, I noticed a minor bug. If I drag-n-drop a file with a space in its path, `mlterm` does not escape the space, in result the path gets broken. Apple Terminal behaves as expected.

<img width="1039" height="150" alt="Image" src="https://github.com/user-attachments/assets/4e18e76c-287a-4e6e-8e27-0a5e8fae3b07" />