Users can change their own email in Authentik and emails are not unique, so
bootstrapOperators (emails) let a user become an identity operator by setting
their email to the owner's. Replaced by bootstrapOperatorSubjects: token sub
(email-looking subs ignored) or, with a verified email, the single active user
with that email whose pk or uuid is configured. Emails in config fail validation.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>