RetroCode And how to start this file manager if it's terminal based like Midnight Commander?
Via SSH? Noob friendly?
Via terminal and connected keyboard? It's a paint to access terminal now btw.! Noob friendly?
I know you want the best for the project and I think your ideas are appreciated 😉
So I think best option would be a call directly from ES to midnight commander. But you know then you need still a keyboard to copy some files. I wrote a script for RetroPie to make this file manager work with a gamepad but this is also not possible in BATO (yet 😉 ).
As I'm not a developer I can just say my personal point of view. I say that all menu options inside ES should be useable by a ready setted gamepad. And to make the setup beginner friendly then there should be no force usage of a keyboard in any way.
Your point:
in keeping with Batocera's "noob-friendliness" a lightweight file manager with a gui might be best.
Yes ... but where is this lightweight and easy to use filemanager? I know that mc can be installed by a package (there may be some issues as @nadenislamarre told)
On the other hand:
You have SAMBA shares, you can access the config file from any mashine. So your PC-OS is a capable file manager.
Conclusion:
Imho it's a waste of time to let someone work in coding a filemanager integreation with gamepad support. It would be the right approach to use a script that translates gamepad inputs to keyboard inputs and then use midnight commander (if mc will work on Bato, but I doubt that there a so big issues with it)