fix(cefr): fix ReferenceError q is not defined in handleOptionTap, bump PWA to v5.4

app/static/js/modules/cefr.js

@@ -352,6 +352,9 @@ async function handleOptionTap(questionId, selectedOption, clickedBtn) {
     if (isAnswered) return;
     isAnswered = true;
 
+    const q = currentQuiz[currentQuestionIdx];
+    const sentence = q ? q.sentence : '';
+
     // Disable all options
     document.querySelectorAll('.cefr-opt-btn').forEach(b => {
         b.disabled = true;
@@ -384,7 +387,7 @@ async function handleOptionTap(questionId, selectedOption, clickedBtn) {
                     ${renderOptionsBreakdown(res.options_breakdown)}
                 `;
                 feedbackBox.classList.remove('hidden');
-                attachBreakdownListeners(feedbackBox, q.sentence);
+                attachBreakdownListeners(feedbackBox, sentence);
             }
         } else {
             sessionStats.mistakes++;
@@ -433,7 +436,7 @@ async function handleOptionTap(questionId, selectedOption, clickedBtn) {
                     ${renderOptionsBreakdown(res.options_breakdown)}
                 `;
                 feedbackBox.classList.remove('hidden');
-                attachBreakdownListeners(feedbackBox, q.sentence);
+                attachBreakdownListeners(feedbackBox, sentence);
             }
         }