fee treatment added

frontend/pshared/lib/data/mapper/payment/fees/line.dart

@@ -0,0 +1,24 @@
+import 'package:pshared/data/dto/payment/fee_line.dart';
+import 'package:pshared/data/mapper/money.dart';
+import 'package:pshared/models/payment/fees/line.dart';
+
+
+extension FeeLineDTOMapper on FeeLineDTO {
+  FeeLine toDomain() => FeeLine(
+    ledgerAccountRef: ledgerAccountRef,
+    amount: amount?.toDomain(),
+    lineType: lineType,
+    side: side,
+    meta: meta,
+  );
+}
+
+extension FeeLineMapper on FeeLine {
+  FeeLineDTO toDTO() => FeeLineDTO(
+    ledgerAccountRef: ledgerAccountRef,
+    amount: amount?.toDTO(),
+    lineType: lineType,
+    side: side,
+    meta: meta,
+  );
+}

frontend/pshared/lib/data/mapper/payment/fees/treatment.dart

@@ -0,0 +1,26 @@
+import 'package:pshared/models/payment/fees/treatment.dart';
+
+
+FeeTreatment feeTreatmentFromValue(String? value) {
+  switch (value) {
+    case 'add_to_source':
+      return FeeTreatment.addToSource;
+    case 'deduct_from_destination':
+      return FeeTreatment.deductFromDestination;
+    case 'unspecified':
+      return FeeTreatment.unspecified;
+    default:
+      throw ArgumentError('Unknown FeeTreatment value: $value');
+  }
+}
+
+String feeTreatmentToValue(FeeTreatment value) {
+  switch (value) {
+    case FeeTreatment.addToSource:
+      return 'add_to_source';
+    case FeeTreatment.deductFromDestination:
+      return 'deduct_from_destination';
+    case FeeTreatment.unspecified:
+      return 'unspecified';
+  }
+}