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/VocabLessonView.vue

@@ -902,11 +902,10 @@
   </div>
 
   <!-- Nach falscher Kapitel-Antwort: zuerst Lösung, dann optional zum Üben -->
-  <div v-if="showExerciseReinforcementDialog" class="dialog-overlay" @click.self="closeExerciseReinforcementDialog">
+  <div v-if="showExerciseReinforcementDialog" class="dialog-overlay">
     <div class="dialog" style="width: 440px; height: auto;">
       <div class="dialog-header">
         <span class="dialog-title">{{ $t('socialnetwork.vocab.courses.exerciseWrongTitle') }}</span>
-        <span class="dialog-close" @click="closeExerciseReinforcementDialog">✖</span>
       </div>
       <div class="dialog-body">
         <p v-if="exerciseReinforcementCorrectAnswer" class="exercise-reinforcement-correct">
@@ -917,10 +916,10 @@
       </div>
       <div class="dialog-footer dialog-footer--stack">
         <button type="button" class="dialog-button dialog-button--primary" @click="confirmExerciseReinforcement">
-          {{ $t('socialnetwork.vocab.courses.exerciseReinforcementGoPractice') }}
+          {{ $t('socialnetwork.vocab.courses.exerciseReinforcementGoPracticeAck') }}
         </button>
         <button type="button" class="dialog-button" @click="closeExerciseReinforcementDialog">
-          {{ $t('socialnetwork.vocab.courses.exerciseReinforcementStay') }}
+          {{ $t('socialnetwork.vocab.courses.exerciseReinforcementStayAck') }}
         </button>
       </div>
     </div>
@@ -1013,6 +1012,8 @@ export default {
       exerciseSequentialIndex: 0,
       /** Aus vorherigen Lektionen (MC-Optionen nach Fragentyp Ziel-/Muttersprache) */
       distractorPool: { target: [], native: [] },
+      /** Fortschritt aller Kurslektionen inkl. lessonState für Spezial-Trainer-Boost */
+      courseProgressList: [],
       /** { [exerciseId]: { options: string[], useTextAnswer: boolean } } */
       mcRandomizedOptions: {},
       lessonStatePersistenceReady: false,
@@ -2038,6 +2039,7 @@ export default {
       this.vocabTrainerPhase = 'current';
       this.vocabTrainerCurrentAttempts = 0;
       this.vocabTrainerReviewAttempts = 0;
+      this.courseProgressList = [];
       this.distractorPool = { target: [], native: [] };
       this.mcRandomizedOptions = {};
       // Reset Flags
@@ -2059,6 +2061,7 @@ export default {
       try {
         const res = await apiClient.get(`/api/vocab/lessons/${this.lessonId}`);
         this.lesson = res.data;
+        await this.loadCourseProgressForBoost();
         debugLog('[VocabLessonView] Geladene Lektion:', this.lesson?.id, this.lesson?.title);
         if (this.$route.query.assistant) {
           this.$nextTick(() => {
@@ -2095,6 +2098,14 @@ export default {
         this.loading = false;
       }
     },
+    async loadCourseProgressForBoost() {
+      try {
+        const { data } = await apiClient.get(`/api/vocab/courses/${this.courseId}/progress`);
+        this.courseProgressList = Array.isArray(data) ? data : [];
+      } catch (e) {
+        this.courseProgressList = [];
+      }
+    },
     focusAssistantCard() {
       const target = this.$refs.assistantCard;
       if (!target || typeof target.scrollIntoView !== 'function') {
@@ -2688,9 +2699,43 @@ export default {
       if (!this.previousVocab || this.previousVocab.length === 0) return [];
       const currentKeys = new Set(this.trainableLessonVocab.map(v => this.getVocabKey(v)));
       const filtered = this.previousVocab.filter(v => !currentKeys.has(this.getVocabKey(v)));
-      // Zufällig mischen und auf 40 begrenzen
-      const shuffled = [...filtered].sort(() => Math.random() - 0.5);
-      return shuffled.slice(0, 40);
+      const filteredByKey = new Map(filtered.map((v) => [this.getVocabKey(v), v]));
+
+      const weakMap = new Map();
+      (this.courseProgressList || []).forEach((entry) => {
+        const lessonId = Number(entry?.lessonId);
+        if (!Number.isFinite(lessonId) || lessonId === Number(this.lessonId)) return;
+        const weakList = Array.isArray(entry?.lessonState?.reviewWeakVocab)
+          ? entry.lessonState.reviewWeakVocab
+          : [];
+        weakList.forEach((w) => {
+          const learning = String(w?.learning || '').trim();
+          const reference = String(w?.reference || '').trim();
+          if (!learning || !reference) return;
+          const key = `${learning}|${reference}`;
+          if (currentKeys.has(key) || !filteredByKey.has(key)) return;
+          const prev = weakMap.get(key) || 0;
+          weakMap.set(key, prev + Math.max(1, Number(w?.wrongCount) || 1));
+        });
+      });
+
+      const boosted = [];
+      Array.from(weakMap.entries())
+        .sort((a, b) => b[1] - a[1])
+        .slice(0, 20)
+        .forEach(([key, score]) => {
+          const vocab = filteredByKey.get(key);
+          if (!vocab) return;
+          const weight = Math.min(4, Math.max(1, Math.round(score)));
+          for (let i = 0; i < weight; i++) {
+            boosted.push(vocab);
+          }
+        });
+
+      const boostedKeySet = new Set(Array.from(weakMap.keys()));
+      const rest = filtered.filter((v) => !boostedKeySet.has(this.getVocabKey(v)));
+      const shuffled = [...rest].sort(() => Math.random() - 0.5);
+      return [...boosted, ...shuffled].slice(0, 40);
     },
     getVocabKey(vocab) {
       return `${vocab.learning}|${vocab.reference}`;