Make email addresses unique

[trey]

Ger has two with the same address.

• https://app.cassettenest.com/innards/auth/user/56/change/
• https://app.cassettenest.com/innards/auth/user/26/change/

[trey]

Relevant: https://simpleisbetterthancomplex.com/article/2021/07/08/what-you-should-know-about-the-django-user-model.html#the-email-field-is-not-unique

[trey]

If you can’t replace the user model, enforce the validation on the forms used to create/update

Well, that sounds a bit tedious. And those forms are kind of built in, aren’t they?

Maybe I could do something here:

https://github.com/trey/cassettenest/blob/375c5275c5e26651b193faa2e6b51e6d4b030567/inventory/forms.py#L11-L17