Fix login logic

        // Look up the internal user

        AppUser? user = await userRepository.GetByUniqueIdAsync(oidcIdentity.Pvi);

        if (user == null)

        {

            // If user does not exist, create it

            user ??= oidcIdentity.ToAppUser();

            await userRepository.AddAsync(user).ConfigureAwait(false);

        }

        // Add the app-specific internal user id claim

        if (user.AppUserId.HasValue)