✨(backend) support email anonymization on user

Add a new property 'email_anonymized' to the User model,
to allow tracking a user's email without any personal data.

In fact, we're dealing with professional data, thus it shouldn't
be subject to the GDPR, however I prefer taking extra care
when working with potentially first and last names.

src/backend/core/models.py

@@ -163,6 +163,13 @@ class User(AbstractBaseUser, BaseModel, auth_models.PermissionsMixin):
         """
         return []
 
+    @property
+    def email_anonymized(self):
+        """Anonymize the email address by replacing the local part with asterisks."""
+        if not self.email:
+            return ""
+        return f"***@{self.email.split('@')[1]}"
+
 
 class Resource(BaseModel):
     """Model to define access control"""