How about an application like gnome-text-editor, which would be friendly to a non-technical user and we wouldn’t be bringing in Qt dependencies.

Also readme of the notepad-next project states:

it should not be considered safe for critically important work

Notepad-Next is replaced by gnome-text-editor app.

This app does not have the standard colorful border

The ID for the window might be: org.gnome.TextEditor.desktop, that can be set for border colors. It will probably look something like AppFlowy, with the window controls part of the application, not the border.

Tested on Lenovo-X1 (nixos-rebuild switch)

* Gnome Text Editor opens in business-vm.

* Text files can be created, opened, edited and saved inside business-vm.

* Green line around the window indicates that it is running in business-vm.

* This is much more simplified than Notepad Next, but I think it does everything needed.

Issues:

* This app does not have the standard colorful border (with minimize, maximize and close buttons). All the other apps have it in business-vm.  This should probably be fixed before merging.

* As a smaller issue: Some options are not working in menus
  
  * In Main Menu 'Dark Style' and 'Light Style' do nothing.
  * In Options Menu (the one left of main menu) only document type can be changed. All the other options seem to do nothing.
  * -> Probably not the end of the world if some of these don't work, but I would guess they should be working in the app?

It has a similar appearance to AppFlowy as @humaidq-tii mentioned. after the new commit.
Missing icons and not working UI are fixed by dconf.

Tested on Lenovo-X1 (nixos-rebuild switch)

• Gnome Text Editor opens in business-vm.
• Text files can be created, opened, edited and saved inside business-vm.
• Green line around the window indicates that it is running in business-vm.
• The app has the standard Ghaf border (with minimize, maximize and close buttons).
• All menu options now work.

Can I make one last small request? The color of the border is quite aggressively green and the contrast in the top bar is not good. As far as I know we don't have guidelines on what the colors should be, but something a bit softer would be great.

Sorry if I was unclear about that in my previous comment. The apps in business-vm have two "borders". The green inside line indicating that the app is in business-vm and then the outside border that almost all apps have.