Frappe LMS: Client-controlled price allows paid-course / certificate purchase for an arbitrary amount

Frappe Learning Management System (LMS) is a learning system that helps users structure their content. Prior to version 2.52.1, the `course/certificate checkout` flow accepts client-controlled pricing, allowing an authenticated user to complete a paid-course or certificate purchase for an amount other than the actual price. This is a business-logic integrity issue; it does not expose other users' data or grant elevated privileges. This issue is fixed in version 2.52.1.