-- ============================================================================
-- Live-path fix #4: add the True/False question type.
--
-- Extends exam_questions.question_type to include 'true_false'. The type reuses
-- existing columns: correct_answer = 'True'|'False', model_answer = justification.
-- Idempotent (re-running MODIFY sets the same enum). MariaDB/MySQL safe.
-- ============================================================================

ALTER TABLE `exam_questions`
  MODIFY `question_type` ENUM('mcq','theory','fill_blank','true_false') NOT NULL DEFAULT 'mcq';
