refactor(exercises): standardize answer language handling across exercise scripts

- Introduced a mechanism to infer answer language based on question phrasing in multiple exercise scripts, enhancing consistency in exercise data.
- Updated question formats to clarify the intent of exercises, improving user understanding and engagement.
- Streamlined the code for better maintainability and clarity in exercise generation processes.

backend/scripts/update-week1-bisaya-exercises.js

@@ -23,6 +23,31 @@ function withTypeName(exerciseTypeName, exercise) {
 
 const LESSON_TITLES = ['Woche 1 - Wiederholung', 'Woche 1 - Vokabeltest'];
 
+function normalizeMcAnswerLanguage(question = '') {
+  const q = String(question || '').trim();
+  if (!q) return null;
+  if (/Wie sagt man/i.test(q) || /auf Bisaya\?/i.test(q)) return 'target';
+  if (/Was bedeutet/i.test(q) || /Was heißt/i.test(q)) return 'native';
+  return null;
+}
+
+function enrichAnswerLanguage(exercises = []) {
+  return exercises.map((exercise) => {
+    const qd = exercise?.questionData;
+    if (!qd || qd.type !== 'multiple_choice') return exercise;
+    if (qd.answerLanguage || qd.answerLanguageId) return exercise;
+    const inferred = normalizeMcAnswerLanguage(qd.question);
+    if (!inferred) return exercise;
+    return {
+      ...exercise,
+      questionData: {
+        ...qd,
+        answerLanguage: inferred
+      }
+    };
+  });
+}
+
 const BISAYA_EXERCISES = {
   'Woche 1 - Wiederholung': [
     { exerciseTypeId: 2, title: 'Wiederholung: Wie sagt man "Wie geht es dir?"?', instruction: 'Wähle die richtige Begrüßung aus.', questionData: { type: 'multiple_choice', question: 'Wie sagt man "Wie geht es dir?" auf Bisaya?', options: ['Kumusta ka?', 'Maayo', 'Salamat', 'Palihug'] }, answerData: { type: 'multiple_choice', correctAnswer: 0 }, explanation: '"Kumusta ka?" ist die Standard-Begrüßung auf Bisaya.' },
@@ -111,7 +136,7 @@ async function updateWeek1BisayaExercises() {
     console.log(`📚 Kurs: ${course.title} (ID: ${course.id})`);
 
     for (const lessonTitle of LESSON_TITLES) {
-      const exercises = BISAYA_EXERCISES[lessonTitle];
+      const exercises = enrichAnswerLanguage(BISAYA_EXERCISES[lessonTitle]);
       if (!exercises || exercises.length === 0) continue;
 
       const lessons = await VocabCourseLesson.findAll({