feat(vocab): implement SRS features and enhance vocabulary management

- Added new endpoints in vocabController for retrieving SRS due items and reviewing SRS items, improving spaced repetition support.
- Updated vocabService to handle SRS item creation and scheduling, ensuring effective tracking of vocabulary exposure.
- Enhanced vocabRouter with new routes for SRS functionalities, facilitating user interaction with spaced repetition features.
- Modified VocabPracticeDialog and VocabCourseView to integrate SRS due items, providing users with timely review opportunities.
- Updated translations and UI elements to reflect new SRS features, enhancing user experience and accessibility.

frontend/src/views/social/VocabLessonView.vue

@@ -3602,6 +3602,23 @@ export default {
     normalizeVocab(s) {
       return this.normalizeComparableText(s);
     },
+    reportSrsReviewForCurrentQuestion(isCorrect) {
+      if (!this.currentVocabQuestion?.vocab || !this.courseId) {
+        return;
+      }
+      const vocab = this.currentVocabQuestion.vocab;
+      apiClient.post('/api/vocab/srs/review', {
+        courseId: this.courseId,
+        lessonId: vocab.lessonId || this.lessonId,
+        itemKey: vocab.itemKey || null,
+        learning: vocab.learning,
+        reference: vocab.reference,
+        direction: this.vocabTrainerDirection,
+        correct: Boolean(isCorrect)
+      }).catch((error) => {
+        console.warn('[VocabLessonView] SRS review could not be saved:', error);
+      });
+    },
     checkVocabAnswer() {
       if (!this.currentVocabQuestion) return;
       
@@ -3638,6 +3655,7 @@ export default {
         stats.wrong++;
         this.queueFailedVocab(this.currentVocabQuestion.vocab);
       }
+      this.reportSrsReviewForCurrentQuestion(this.vocabTrainerLastCorrect);
       
       this.vocabTrainerAnswered = true;