feat(vocab): enhance feedback acknowledgment and localization in vocabulary lessons

- Added acknowledgment messages for exercise reinforcement in German, English, and Spanish localization files to improve user guidance.
- Updated VocabLessonView to include a feedback acknowledgment button, enhancing user interaction after answering questions.
- Implemented logic to track feedback acknowledgment state, improving the flow of lesson reviews and user experience.

frontend/src/views/social/VocabLessonReviewView.vue

@@ -49,6 +49,14 @@
           >
             {{ $t('socialnetwork.vocab.courses.checkAnswer') }}
           </button>
+          <button
+            v-if="needsFeedbackAck"
+            type="button"
+            class="button-secondary"
+            @click="advanceAfterFeedback"
+          >
+            Gelesen, weiter
+          </button>
         </div>
 
         <p v-if="feedback" class="review-feedback" :class="feedbackCorrect ? 'ok' : 'bad'">
@@ -80,8 +88,10 @@ export default {
       typedAnswer: '',
       feedback: '',
       feedbackCorrect: false,
+      needsFeedbackAck: false,
       correctCount: 0,
-      reviewDone: false
+      reviewDone: false,
+      weakVocabMap: {}
     };
   },
   computed: {
@@ -103,6 +113,9 @@ export default {
     normalize(s) {
       return String(s || '').trim().toLowerCase();
     },
+    getItemKey(item) {
+      return `${String(item?.gloss || '').trim()}|${String(item?.target || '').trim()}`;
+    },
     parseCorePatterns() {
       const raw = this.lesson?.didactics?.corePatterns || [];
       const out = [];
@@ -151,6 +164,7 @@ export default {
       this.feedback = '';
       this.selectedOption = '';
       this.typedAnswer = '';
+      this.needsFeedbackAck = false;
       if (!this.currentItem) return;
       this.mode = this.currentItem.gloss ? 'multiple_choice' : 'typing';
       if (this.mode === 'multiple_choice') {
@@ -170,26 +184,85 @@ export default {
       if (isCorrect) {
         this.correctCount += 1;
         this.feedback = this.$t('socialnetwork.vocab.courses.correct');
+        this.needsFeedbackAck = false;
+        window.setTimeout(() => {
+          this.advanceAfterFeedback();
+        }, 550);
       } else {
         this.feedback = `${this.$t('socialnetwork.vocab.courses.wrong')} - ${this.$t('socialnetwork.vocab.courses.correctAnswer')}: ${this.mode === 'multiple_choice' ? this.currentItem.gloss : this.currentItem.target}`;
+        this.needsFeedbackAck = true;
+        const key = this.getItemKey(this.currentItem);
+        const existing = this.weakVocabMap[key] || {
+          learning: this.currentItem.gloss || '',
+          reference: this.currentItem.target || '',
+          wrongCount: 0,
+          lastWrongAt: ''
+        };
+        existing.wrongCount += 1;
+        existing.lastWrongAt = new Date().toISOString();
+        this.weakVocabMap[key] = existing;
       }
-
-      window.setTimeout(async () => {
-        this.currentIndex += 1;
-        if (this.currentIndex >= this.reviewQueue.length) {
-          await this.finishReview();
-          return;
-        }
-        this.setupCurrent();
-      }, 500);
+    },
+    async advanceAfterFeedback() {
+      this.currentIndex += 1;
+      if (this.currentIndex >= this.reviewQueue.length) {
+        await this.finishReview();
+        return;
+      }
+      this.setupCurrent();
     },
     async finishReview() {
       this.reviewDone = true;
       try {
+        let mergedWeak = Object.values(this.weakVocabMap);
+        try {
+          const { data: progressList } = await apiClient.get(`/api/vocab/courses/${this.courseId}/progress`);
+          const existingProgress = Array.isArray(progressList)
+            ? progressList.find((p) => Number(p.lessonId) === Number(this.lessonId))
+            : null;
+          const existingWeak = Array.isArray(existingProgress?.lessonState?.reviewWeakVocab)
+            ? existingProgress.lessonState.reviewWeakVocab
+            : [];
+          const map = new Map();
+          existingWeak.forEach((entry) => {
+            const key = `${String(entry?.learning || '').trim()}|${String(entry?.reference || '').trim()}`;
+            if (!key) return;
+            map.set(key, {
+              learning: String(entry?.learning || '').trim(),
+              reference: String(entry?.reference || '').trim(),
+              wrongCount: Math.max(0, Number(entry?.wrongCount) || 0),
+              lastWrongAt: String(entry?.lastWrongAt || '')
+            });
+          });
+          mergedWeak.forEach((entry) => {
+            const key = `${String(entry?.learning || '').trim()}|${String(entry?.reference || '').trim()}`;
+            if (!key) return;
+            const prev = map.get(key);
+            if (!prev) {
+              map.set(key, entry);
+            } else {
+              map.set(key, {
+                learning: prev.learning || entry.learning,
+                reference: prev.reference || entry.reference,
+                wrongCount: Math.max(0, Number(prev.wrongCount) || 0) + Math.max(0, Number(entry.wrongCount) || 0),
+                lastWrongAt: entry.lastWrongAt || prev.lastWrongAt
+              });
+            }
+          });
+          mergedWeak = Array.from(map.values())
+            .filter((entry) => entry.learning && entry.reference)
+            .sort((a, b) => (b.wrongCount || 0) - (a.wrongCount || 0))
+            .slice(0, 40);
+        } catch (mergeErr) {
+          console.warn('Konnte bestehende Review-Schwachstellen nicht laden:', mergeErr);
+        }
         await apiClient.put(`/api/vocab/lessons/${this.lessonId}/progress`, {
           completed: true,
           score: 100,
-          timeSpentMinutes: 1
+          timeSpentMinutes: 1,
+          lessonState: {
+            reviewWeakVocab: mergedWeak
+          }
         });
       } catch (e) {
         console.error('Review-Fortschritt konnte nicht gespeichert werden:', e);