feat: add save sessionStorage to scroll and category on shop

frontend/src/pages/Shop.jsx

@@ -7,9 +7,10 @@ import CardItem from "../components/CardItem";
 export default function Shop() {
   const [items, setItems] = useState([]);
   const [categories, setCategories] = useState([]);
-  const [activeCategory, setActiveCategory] = useState("все");
+  const [activeCategory, setActiveCategory] = useState(
+    () => sessionStorage.getItem("shopCategory") || "все",
+  );
   const [loading, setLoading] = useState(true);
-
   useEffect(() => {
     Promise.all([api.getAllItems(), api.getAllCategories()])
       .then(([itemsRes, categoriesRes]) => {
@@ -24,16 +25,32 @@ export default function Shop() {
       });
   }, []);
 
+  // восстановление скролла после загрузки товаров
+  useEffect(() => {
+    if (!loading && items.length > 0) {
+      const saved = sessionStorage.getItem("shopScroll");
+      if (saved) {
+        window.scrollTo(0, parseInt(saved));
+        sessionStorage.removeItem("shopScroll");
+      }
+    }
+  }, [loading, items]);
+
   const filteredItems = useMemo(() => {
     return activeCategory === "все"
       ? items || []
       : (items || []).filter((item) => {
         if (!item || !item.category) return false;
-
         return item.category.toLowerCase() === activeCategory.toLowerCase();
       });
   }, [items, activeCategory]);
 
+  // сохранить позицию и категорию перед уходом на товар
+  const handleNavigateToItem = () => {
+    sessionStorage.setItem("shopScroll", window.scrollY);
+    sessionStorage.setItem("shopCategory", activeCategory);
+  };
+
   const handleAddToCart = async (product, selectedWeight) => {
     try {
       await api.addToCart({
@@ -48,11 +65,11 @@ export default function Shop() {
   };
 
   if (loading) {
-    return(
+    return (
       <PageLayout>
         <p className="text-white grow">Загрузка...</p>
       </PageLayout>
-    )
+    );
   }
 
   return (
@@ -68,7 +85,12 @@ export default function Shop() {
         />
         <div className="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-6 mb-4">
           {filteredItems.map((item) => (
-            <CardItem key={item.id} item={item} onAddToCart={handleAddToCart} />
+            <CardItem
+              key={item.id}
+              item={item}
+              onAddToCart={handleAddToCart}
+              onNavigate={handleNavigateToItem}
+            />
           ))}
         </div>
       </main>