feat: füge Unterstützung für temporäre gap_fill-Übungen aus chapterLexemeTraining hinzu

backend/services/vocabService.js

@@ -2881,6 +2881,23 @@ export default class VocabService {
     });
 
     const plainLesson = lesson.get({ plain: true });
+    // Normalize exercise types: if question text contains clear gap placeholders,
+    // ensure the questionData.type is 'gap_fill' so the frontend renders the gap UI.
+    (plainLesson.grammarExercises || []).forEach((ex) => {
+      try {
+        const qData = typeof ex.questionData === 'string' ? JSON.parse(ex.questionData || '{}') : (ex.questionData || {});
+        const text = String(qData.text || qData.question || '').trim();
+        const hasUnderscoreGap = /_{3,}/.test(text);
+        const hasBraceGap = /\{\s*gap\s*\}/i.test(text);
+        const hasParenPlaceholders = /\(\s*_{0,}\s*\)/.test(text);
+        if ((hasUnderscoreGap || hasBraceGap || hasParenPlaceholders) && qData.type !== 'gap_fill') {
+          qData.type = 'gap_fill';
+          ex.questionData = qData;
+        }
+      } catch (err) {
+        // ignore parse errors
+      }
+    });
     
     // Lade Vokabeln aus vorherigen Lektionen (für Wiederholung UND für gemischten Vokabeltrainer)
     if (plainLesson.lessonNumber > 1) {

frontend/src/views/social/VocabLessonView.vue

@@ -2816,6 +2816,30 @@ export default {
         }
         await this.$nextTick();
         let exercises = this.effectiveExercises;
+        // Wenn das Backend eine chapterLexemeTraining-Liste liefert, wandle sie
+        // in temporäre gap_fill-Übungen um und mische sie in die grammarExercises
+        try {
+          if (this.lesson && Array.isArray(this.lesson.chapterLexemeTraining) && this.lesson.chapterLexemeTraining.length) {
+            const temps = this.lesson.chapterLexemeTraining.map((item, idx) => {
+              const id = `cht-${this.lesson.id}-${String(item.id)}`;
+              return {
+                id,
+                lessonId: this.lesson.id,
+                exerciseTypeId: 1,
+                title: `Kapitel-Vokabel: ${item.learning}`,
+                instruction: this.$t('socialnetwork.vocab.courses.fillTheBlank') || 'Lückentext',
+                questionData: { type: 'gap_fill', text: `{gap} (${item.learning})` },
+                answerData: { type: 'gap_fill', answers: [item.reference] }
+              };
+            });
+            this.lesson.grammarExercises = Array.isArray(this.lesson.grammarExercises)
+              ? [...this.lesson.grammarExercises, ...temps]
+              : temps;
+            exercises = this.effectiveExercises;
+          }
+        } catch (err) {
+          console.warn('[VocabLessonView] Fehler beim Einfügen von chapterLexemeTraining:', err);
+        }
         if (!exercises || exercises.length === 0) {
           debugLog('[VocabLessonView] Lade Übungen separat...');
           await this.loadGrammarExercises();