Looks simple enough. The choice of Godot for a UI library is an interesting one; how big is the program in the end?
I would suggest being a bit more explicit about files: Which ones are in the working set; which one is currently being worked on, that sort of thing. Having a file list (even if it's hidden in a drawer or something) before starting the conversion helps the user verify that the correct files are being worked on. Seeing which file is currently being processed might be useful for troubleshooting or just to see how far along the process is.