fix(vocabLessonReview): improve input normalization by trimming punctuation

- Enhanced the `normalize` method to trim trailing punctuation marks (.,!?;:) from input strings, ensuring cleaner and more consistent user input.
- Added logic to replace multiple spaces with a single space, improving the overall formatting of normalized strings.

frontend/src/views/social/VocabLessonReviewView.vue

@@ -111,7 +111,9 @@ export default {
   },
   methods: {
     normalize(s) {
-      return String(s || '').trim().toLowerCase();
+      const base = String(s || '').trim().toLowerCase();
+      // Satzzeichen am Ende ignorieren (Punkt, Fragezeichen, Ausrufezeichen, Komma, Strichpunkt, Doppelpunkt)
+      return base.replace(/[.,!?;:]+$/g, '').replace(/\s+/g, ' ');
     },
     getItemKey(item) {
       return `${String(item?.gloss || '').trim()}|${String(item?.target || '').trim()}`;