[SHOPTIME-3717] Order / 쿠폰 선택을 해도 혜택이 노출되지 않으며 재 진입시 선택이 유지되지 않음

redux에서 coupon data 가져와서 조회

com.twin.app.shoptime/src/views/CheckOutPanel/components/OffersPromotionItemCard.jsx

@@ -44,11 +44,20 @@ export default memo(function OffersPromotionItemCard({
   const priceTotalData = useSelector(
     (state) => state.checkout?.checkoutTotalData
   );
+  const selectedCoupon = useSelector(
+    (state) => state.checkout?.selectedCoupons?.[prdtId]
+  );
 
   const dispatch = useDispatch();
-  const [selectedIndex, setSelectedIndex] = useState(-1);
   const [openChk, setOpenChk] = useState(false);
 
+  const selectedIndex = useMemo(() => {
+    if (!selectedCoupon) return -1;
+    return prdtCoupon.findIndex(
+      (coupon) => coupon.cpnNo === selectedCoupon.cpnNo
+    );
+  }, [selectedCoupon, prdtCoupon]);
+
   const formattedPrices = useMemo(() => {
     return {
       discounted: priceTotalData?.totProdPrc
@@ -64,7 +73,6 @@ export default memo(function OffersPromotionItemCard({
   const handleCouponSelect = (e) => {
     const selectedIdx = e.selected;
     const selected = prdtCoupon[selectedIdx];
-    setSelectedIndex(selectedIdx);
     dispatch(updateSelectedCoupon(prdtId, selected));
   };