Backend enforcement of minimum order quantities

Previously, minimum order quantity rules were only applied on the frontend of AI Commerce Cloud webshops. This left room for manipulation attempts, as advanced users could bypass the restriction and add fewer items than allowed. With this update, the backend now strictly enforces minimum order quantities when products are added to the cart. This ensures consistency, prevents abuse, and guarantees that customers must always meet the defined minimum order requirements. The change enhances platform security, order accuracy, and compliance with store policies.