Save after export adds ".zip" extension

[i-make-robots]

To Reproduce Steps to reproduce the behavior:

1. Load a file
2. Export it.
3. Load or save another file.
4. "file does not exist". investigating shows ".zip" extension silently added.

Expected behavior Not that. save and load should use ".ro" extension. only export should use ".zip"

Platform (please complete the following information):

• v2.105