useComputed

import { computed } from '@sinuxjs/core';
import { useComputed } from '@sinuxjs/react';

const totalPrice = computed(cartStore, s =>
  s.items.reduce((sum, item) => sum + item.price, 0)
);

function CartTotal() {
  const total = useComputed(totalPrice);
  return <span>${total.toFixed(2)}</span>;
}

• Subscribes to a computed value
• Re-renders only when the derived value changes
• Uses useSyncExternalStore internally