fixed some cart style

src/app/api/useCart.js

@@ -0,0 +1,37 @@
+// hooks/useCart.js - YENİ DOSYA
+import { useMemo } from 'react';
+import { useGetCartQuery } from './cartApi';
+
+export const useCart = () => {
+  const { data: cartData, ...rest } = useGetCartQuery(undefined, {
+    pollingInterval: 0,
+    refetchOnMountOrArgChange: false,
+    refetchOnFocus: false,
+    refetchOnReconnect: false,
+  });
+
+  const cartItems = useMemo(() => {
+    if (!cartData?.data || typeof cartData.data !== 'object') return [];
+    return Object.values(cartData.data).flat();
+  }, [cartData]);
+
+  const cartCount = useMemo(() => {
+    return cartItems.reduce((total, item) => {
+      return total + (parseInt(item.product_quantity, 10) || 0);
+    }, 0);
+  }, [cartItems]);
+
+  const getCartItem = (productId) => {
+    return cartItems.find(
+      item => item.product?.id === productId || item.product_id === productId
+    );
+  };
+
+  return {
+    cartData,
+    cartItems,
+    cartCount,
+    getCartItem,
+    ...rest
+  };
+};