fix(VocabPracticeDialog): adjust success tracking for hard-phase drills

- Updated the success tracking logic to prevent inflating normal success counters during hard-phase drills, ensuring accurate representation of user progress.
- Introduced a condition to separate tracking for hard-phase activities, enhancing the integrity of vocabulary rotation and user experience.

frontend/src/dialogues/socialnetwork/VocabPracticeDialog.vue

@@ -933,8 +933,13 @@ export default {
       if (!id) return;
       const st = this.perId[id] || { c: 0, w: 0, streak: 0, lastAsked: 0 };
       if (isCorrect) {
-        st.c += 1;
-        st.streak = st.streak >= 0 ? st.streak + 1 : 1;
+        // Hard-phase drills are tracked separately via hardMasteryByKey.
+        // We avoid inflating normal success counters here, otherwise the
+        // graduated vocab can become too unlikely in regular rotation.
+        if (!this.hardPhaseActive) {
+          st.c += 1;
+          st.streak = st.streak >= 0 ? st.streak + 1 : 1;
+        }
         if (this.hardPhaseActive && this.current) {
           const key = this.getHardKey(this.current);
           this.hardMasteryByKey[key] = Math.max(0, Number(this.hardMasteryByKey[key]) || 0) + 1;