Toga experimentation (2025)

[mhsmith]

Corresponding Toga PR:

• Invent experimentation (2025) beeware/toga#3157

[mhsmith]

We decided not to pursue this any further. This PR contains the most recent prototype, which was able to run the calculator example on top of Toga as follows:

• Add the Toga repository as a Git submodule, and include the necessary packages in invent.tar.gz.
• Replace the Invent public APIs of Column, Row, Button, Label and TextInput with the corresponding Toga classes, and move the PyScript-based implementations of those widgets into a Toga backend.
• Turn Grid into a custom Toga widget, but keep it outside the Toga repository for now.

The next steps would have been:

• Extend this to the farmyard example.
• Try running it on a different Toga backend.

[ntoll]

Thank you so much for this. 🤗