Short answers to the specific questions that come up when a prototype has to become a product.
An MVP is the smallest complete path through your product — one user, one journey, finished properly. It is not a cheap version of everything; it is a real version of one thing.
A Product Twin is the production version of the app you build in Lovable. You keep prompting and changing your mind; when a version is right you send it to us, and we engineer, test, release and support the version your users actually touch.
Row-level security is a database rule that decides, per row, which users may read or change it. Because the database enforces it, the rule holds no matter how the request arrives — through your app, through an API call, or through someone else's script.