Let me know if you think this is a good idea. I'd be happy to try to contribute.
phx.gen.inertia, which would work nearly the same as phx.gen.html:
It would generate Inertia-based controllers and tests, while still reusing Phoenix templates for the regular context, schema and migration templates. The views side (frontend) would be out of scope, I assume, due to the variety of options (or we could check package.json to detect the framework).
I think generators are always helpful for people starting out and for AI-assisted development.