[상품 디테일] 스크롤 다운 버튼 처리건.

1. documentHeight의 초기값 0으로 변경.
	2. 버튼 눌렀을때 documentHeight 값을 알수없어 이부분 전체 영역 계산으로 변경.
 	3. reviewHeight부분 필요없음으로 인한 제거.

com.twin.app.shoptime/src/views/DetailPanel/ProductAllSection/ProductAllSection.jsx

@@ -164,10 +164,10 @@ export default function ProductAllSection({
   const dispatch = useDispatch();
   const [currentHeight, setCurrentHeight] = useState(0);
   //하단부분까지 갔을때 체크용
-  const [documentHeight, setDocumentHeight] = useState();
+  const [documentHeight, setDocumentHeight] = useState(0);
   const [isBottom, setIsBottom] = useState(false);
   //버튼 active 표시용
-  const [reviewHeight, setReviewHeight] = useState(0);
+
   const [activeProductBtn, setActiveProductBtn] = useState(false);
   const [activeReviewBtn, setActiveReviewBtn] = useState(false);
   const [activeYouMayLikeBtn, setActiveYouMayLikeBtn] = useState(false);
@@ -337,15 +337,20 @@ export default function ProductAllSection({
   const handleArrowClickAlternative = useCallback(() => {
     const currentHeight = scrollPositionRef.current;
     const scrollAmount = 200;
+
     scrollTop({
       y: currentHeight + scrollAmount,
       animate: true,
     });
-    if (documentHeight) {
-      const isAtBottom = scrollPositionRef.current + 944 >= documentHeight;
-      if (isAtBottom !== isBottom) {
-        setIsBottom(isAtBottom);
-      }
+
+    const isAtBottom =
+      scrollPositionRef.current + 1100 >=
+      (productDetailRef.current?.scrollHeight || 0) +
+        (descriptionRef.current?.scrollHeight || 0) +
+        (reviewRef.current?.scrollHeight || 0) +
+        (youMayAlsoLikelRef.current?.scrollHeight || 0);
+    if (isAtBottom) {
+      setIsBottom(isAtBottom);
     }
   }, []);
 
@@ -394,11 +399,6 @@ export default function ProductAllSection({
         (descriptionRef.current?.scrollHeight || 0) +
         (reviewRef.current?.scrollHeight || 0)
     );
-    setReviewHeight(
-      (productDetailRef.current?.scrollHeight || 0) +
-        (descriptionRef.current?.scrollHeight || 0) +
-        (reviewRef.current?.scrollHeight || 0)
-    );
   }, [
     productDetailRef.current,
     descriptionRef.current,