const handlePurchase = async (pkg) => {
  try {
    const { customerInfo } = await Purchases.purchasePackage(pkg);
    if (customerInfo.entitlements.active['premium']) {
      router.replace('/(main)');
    }
  } catch (error) {
    if (!error.userCancelled) {
      Alert.alert('Error', 'Purchase failed');
    }
  }
};