Reject creating a second practice on the same course, module, or lesson with 409 Conflict, and enforce the rule in the database via unique partial indexes.
Co-authored-by: Cursor <cursoragent@cursor.com>
Introduce lms_personas table, repoint practice persona_id FKs off users, validate persona refs on LMS and exam-prep practice flows, personas.* RBAC permissions, and OpenAPI docs.
Co-authored-by: Cursor <cursoragent@cursor.com>
