fix: play button resumes paused track instead of switching to selected track

index.html

@@ -1480,6 +1480,10 @@ audioElA.addEventListener('pause', onPause);
 audioElB.addEventListener('pause', onPause);
 playBtn.addEventListener('click', () => {
   if (tracks.length === 0) return;
+  if (audio.paused && currentIndex >= 0) {
+    audio.play().catch(() => {});
+    return;
+  }
   const selArr = [...selectedIndices];
   const sel = selArr.length > 0 ? selArr[0] : -1;
   if (sel >= 0 && sel !== currentIndex) {