Title: AI coding agent should warn that Core.SendEmail doesn't support external email addresses Message: The AI coding agent repeatedly guided me to implement Core.SendEmail to send emails to external recipients, without ever warning me that this function is restricted to users registered within the app. As a result, I wasted a significant number of credits trying to make something work that was simply impossible. Request: The AI agent should systematically inform users of this limitation as soon as it detects a use case involving external recipients, and immediately suggest the appropriate alternative (e.g. Resend). This would prevent unnecessary credit loss and frustration for users.