fix: some problems are fixed

lib/core/payment/bazaar_payment_gateway.dart

@@ -21,12 +21,12 @@ class BazaarPaymentGateway implements PaymentGateway {
   }
 
   @override
-  Future<PurchaseResult> purchase(String productSku) async {
+  Future<PurchaseResult> purchase(String productSku, {String payload = ''}) async {
     try {
       await connect();
       final info = await FlutterPoolakey.purchase(
         productSku,
-        payload: 'hakemsho',
+        payload: payload.isNotEmpty ? payload : 'hakemsho',
       );
       if (info.purchaseToken.isEmpty) {
         return const PurchaseResult.failure();

lib/core/payment/dev_payment_gateway.dart

@@ -11,7 +11,7 @@ class DevPaymentGateway implements PaymentGateway {
   Future<void> connect() async {}
 
   @override
-  Future<PurchaseResult> purchase(String productSku) async {
+  Future<PurchaseResult> purchase(String productSku, {String payload = ''}) async {
     final stamp = DateTime.now().millisecondsSinceEpoch;
     return PurchaseResult.success(
       token: 'dev-$productSku-$stamp',

lib/core/payment/myket_payment_gateway.dart

@@ -19,10 +19,12 @@ class MyketPaymentGateway implements PaymentGateway {
   }
 
   @override
-  Future<PurchaseResult> purchase(String productSku) async {
+  Future<PurchaseResult> purchase(String productSku, {String payload = ''}) async {
     await connect();
-    final Map<dynamic, dynamic> result =
-        await MyketIAP.launchPurchaseFlow(sku: productSku, payload: 'hakemsho');
+    final Map<dynamic, dynamic> result = await MyketIAP.launchPurchaseFlow(
+      sku: productSku,
+      payload: payload.isNotEmpty ? payload : 'hakemsho',
+    );
 
     final Purchase? purchase = result[MyketIAP.PURCHASE] as Purchase?;
     if (purchase == null || purchase.mToken.isEmpty) {

lib/core/payment/payment_gateway.dart

@@ -33,7 +33,9 @@ abstract class PaymentGateway {
   String get store;
 
   /// جریانِ خریدِ [productSku] (همان UUIDِ محصول در پنلِ فروشگاه) را باز می‌کند.
-  Future<PurchaseResult> purchase(String productSku);
+  /// [payload] در فروشگاه ذخیره و در پنلِ توسعه‌دهنده نمایش داده می‌شود؛ اینجا
+  /// شماره‌ی موبایلِ کاربر را می‌فرستیم تا خرید قابلِ ردیابی باشد.
+  Future<PurchaseResult> purchase(String productSku, {String payload = ''});
 
   /// اتصالِ اولیه (در صورتِ نیاز). پیش از اولین خرید صدا زده می‌شود.
   Future<void> connect() async {}