Split creators out of identity

src/Application/Users/Commands/CreateUser.cs

@@ -28,8 +28,10 @@ public class CreateUserCommandHandler : IRequestHandler<CreateUserCommand, IResu
 
         var user = await _identityService.FindUserByEmailAsync(request.EmailAddress);
 
+        if (user is null) throw new InvalidOperationException("This should never happen, we just created the user.");
+        
         await _context.SaveChangesAsync(cancellationToken);
 
-        return Results.Ok(new Guid(user?.Id ?? string.Empty));
+        return Results.Ok(user.Id);
     }
 }