By: Michael Lynch <git@mtlynch.io>
Return ErrUnregisteredEmail from NewSender instead of empty entry NewSender now returns a magiclogin.ErrUnregisteredEmail error for unknown addresses instead of silently returning an empty token entry. Callers handle the error explicitly and redirect to /login/check-email. Inline LoginConfirmPath into the dev creator and remove login_redirect.go. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>