🧑‍💻(models) improve user str representation

Improve user model str representation to display name or email
if provided. Otherwise, returns sub as last resort.

src/backend/core/models.py

@@ -230,11 +230,7 @@ class User(AbstractBaseUser, BaseModel, auth_models.PermissionsMixin):
         verbose_name_plural = _("users")
 
     def __str__(self):
-        return (
-            str(self.profile_contact)
-            if self.profile_contact
-            else self.email or str(self.sub)
-        )
+        return self.name if self.name else self.email or f"User {self.sub}"
 
     def save(self, *args, **kwargs):
         """