unified gateway interfaces

frontend/pshared/lib/data/dto/payment/intent/payment.dart

@@ -20,6 +20,9 @@ class PaymentIntentDTO {
   @JsonKey(name: 'settlement_mode')
   final String? settlementMode;
 
+  @JsonKey(name: 'settlement_currency')
+  final String? settlementCurrency;
+
   final Map<String, String>? attributes;
   final CustomerDTO? customer;
 
@@ -30,6 +33,7 @@ class PaymentIntentDTO {
     this.amount,
     this.fx,
     this.settlementMode,
+    this.settlementCurrency,
     this.attributes,
     this.customer,
   });

frontend/pshared/lib/data/mapper/payment/intent/payment.dart

@@ -15,6 +15,7 @@ extension PaymentIntentMapper on PaymentIntent {
     amount: amount?.toDTO(),
     fx: fx?.toDTO(),
     settlementMode: settlementModeToValue(settlementMode),
+    settlementCurrency: settlementCurrency,
     attributes: attributes,
     customer: customer?.toDTO(),
   );
@@ -28,6 +29,7 @@ extension PaymentIntentDTOMapper on PaymentIntentDTO {
     amount: amount?.toDomain(),
     fx: fx?.toDomain(),
     settlementMode: settlementModeFromValue(settlementMode),
+    settlementCurrency: settlementCurrency,
     attributes: attributes,
     customer: customer?.toDomain(),
   );