feat(VocabLessonView): enhance review lesson logic and vocabulary handling

- Added logic to adjust vocabulary blending and switching conditions based on lesson type and didactic mode, improving the learning experience during review lessons.
- Implemented dynamic thresholds for switching between multiple choice and typing modes based on success rates and lesson context.
- Enhanced vocabulary source selection to incorporate a review share, optimizing the question pool for better engagement during typing sessions.

frontend/src/views/social/VocabLessonView.vue

@@ -1156,10 +1156,52 @@ export default {
       if (!this.hasPreviousVocab) {
         return 0;
       }
+      const lessonType = String(this.lesson?.lessonType || '').toLowerCase();
+      const didacticMode = String(this.lessonPedagogy?.didacticMode || '').toLowerCase();
+      const isReviewLesson = ['review', 'vocab_review'].includes(lessonType)
+        || ['review', 'vocab_review', 'intensive_review'].includes(didacticMode);
+
+      if (isReviewLesson) {
+        // In Wiederholungslektionen soll altes Material frueher und staerker einfliesen.
+        // Start: ~35%, Ramp-up bis max ~75%.
+        const blendStart = Math.max(2, Math.ceil(this.trainerNewFocusTarget * 0.2));
+        const rampWindow = Math.max(6, Math.ceil(this.trainerNewFocusTarget * 0.5));
+        const progressPastBlendStart = Math.max(0, this.vocabTrainerCurrentAttempts - blendStart);
+        const normalizedRamp = Math.min(1, progressPastBlendStart / rampWindow);
+        return Math.min(0.75, 0.35 + (normalizedRamp * 0.4));
+      }
+
       const progressPastBlendStart = Math.max(0, this.vocabTrainerCurrentAttempts - this.trainerReviewBlendStart);
       const normalizedRamp = Math.min(1, progressPastBlendStart / this.trainerReviewRampWindow);
       return Math.min(0.55, normalizedRamp * 0.55);
     },
+    typingCurrentLessonShare() {
+      if (!this.hasPreviousVocab) {
+        return 1;
+      }
+      const lessonType = String(this.lesson?.lessonType || '').toLowerCase();
+      const didacticMode = String(this.lessonPedagogy?.didacticMode || '').toLowerCase();
+      const isReviewLesson = ['review', 'vocab_review'].includes(lessonType)
+        || ['review', 'vocab_review', 'intensive_review'].includes(didacticMode);
+
+      if (isReviewLesson) {
+        return Math.max(0.25, 1 - this.currentReviewShare);
+      }
+
+      // Normale Lektion: Progressives Streuen im Typing-Modus
+      // Start 100% aktuelle Lektion -> dann 90% -> später 50%.
+      const startRampAt = Math.max(3, Math.ceil(this.trainerNewFocusTarget * 0.3));
+      const midRampAt = Math.max(startRampAt + 1, Math.ceil(this.trainerNewFocusTarget * 0.6));
+      const attempts = Math.max(0, Number(this.vocabTrainerCurrentAttempts) || 0);
+
+      if (attempts < startRampAt) {
+        return 1;
+      }
+      if (attempts < midRampAt) {
+        return 0.9;
+      }
+      return 0.5;
+    },
     canAccessExercises() {
       if (!this.hasExercises) return false;
       if (this.exerciseNeedsReinforcement) return false;
@@ -3349,10 +3391,19 @@ export default {
 
       this.vocabTrainerPhase = this.hasPreviousVocab && this.currentReviewShare > 0 ? 'mixed' : 'current';
 
-      if (this.vocabTrainerMode === 'multiple_choice' && this.vocabTrainerTotalAttempts >= this.trainerExerciseUnlockAttempts) {
+      const lessonType = String(this.lesson?.lessonType || '').toLowerCase();
+      const didacticMode = String(this.lessonPedagogy?.didacticMode || '').toLowerCase();
+      const isReviewLesson = ['review', 'vocab_review'].includes(lessonType)
+        || ['review', 'vocab_review', 'intensive_review'].includes(didacticMode);
+      const switchAfterAttempts = isReviewLesson
+        ? Math.max(8, Math.ceil(this.trainerExerciseUnlockAttempts * 0.35))
+        : this.trainerExerciseUnlockAttempts;
+      const requiredSuccessRate = isReviewLesson ? 75 : 80;
+
+      if (this.vocabTrainerMode === 'multiple_choice' && this.vocabTrainerTotalAttempts >= switchAfterAttempts) {
         const successRate = (this.vocabTrainerCorrect / this.vocabTrainerTotalAttempts) * 100;
-        if (successRate >= 80) {
-          debugLog('[VocabLessonView] Mixed-Phase abgeschlossen, wechsle zu Typing');
+        if (successRate >= requiredSuccessRate) {
+          debugLog('[VocabLessonView] Wechsle zu Typing (Abruf staerken)');
           this.vocabTrainerMode = 'typing';
           this.vocabTrainerAutoSwitchedToTyping = true;
           this.vocabTrainerPool = [...this.trainableLessonVocab, ...this.vocabTrainerMixedPool];
@@ -3508,9 +3559,13 @@ export default {
       }
 
       if (!dueRepeatVocab && this.vocabTrainerMode === 'typing') {
-        sourcePool = this.vocabTrainerPool;
-        if (this.vocabTrainerMixedPool.length > 0 && Math.random() < 0.35) {
+        const typingReviewShare = Math.max(0, 1 - this.typingCurrentLessonShare);
+        if (this.vocabTrainerMixedPool.length > 0 && typingReviewShare > 0 && Math.random() < typingReviewShare) {
+          sourcePool = this.vocabTrainerMixedPool;
           questionSource = 'review';
+        } else {
+          sourcePool = this.trainableLessonVocab;
+          questionSource = 'current';
         }
       } else if (!dueRepeatVocab && this.vocabTrainerMixedPool.length > 0 && this.currentReviewShare > 0 && Math.random() < this.currentReviewShare) {
         sourcePool = this.vocabTrainerMixedPool;