Return to create form after validation error for Ash authentication

The tooling clearly could use some improvement for the non-live view cases here.

@jimsynz might be able to help more than me. Does the reason contain a failed form in this case? Or just the error from the form? Or perhaps the conn contains the failed form in the assigns?

What you’d want to do ideally is reassigned the form that failed to submit. That would render errors and old values.