migration to address book service

frontend/pweb/lib/utils/payment/label.dart

@@ -1,7 +1,10 @@
 import 'package:flutter/widgets.dart';
 
+import 'package:pshared/models/payment/methods/type.dart';
 import 'package:pshared/models/payment/type.dart';
 
+import 'package:pweb/utils/payment/masking.dart';
+
 import 'package:pweb/generated/i18n/app_localizations.dart';
 
 
@@ -15,3 +18,15 @@ String getPaymentTypeLabel(BuildContext context, PaymentType type) {
     PaymentType.cryptoAddress => l10n.paymentTypeCryptoAddress,
   };
 }
+
+String? _displayString(PaymentMethod m) => switch (m.type) {
+  PaymentType.card => maskCardNumber(m.cardData?.pan),
+  PaymentType.bankAccount => m.bankAccountData?.accountNumber,
+  PaymentType.iban => m.ibanData?.iban,
+  PaymentType.wallet => m.walletData?.walletId,
+  PaymentType.cryptoAddress => m.cryptoAddressData?.address,
+};
+
+String getPaymentTypeDescription(BuildContext context, PaymentMethod m) {
+  return _displayString(m) ?? AppLocalizations.of(context)!.notSet;
+}

frontend/pweb/lib/utils/payment/masking.dart

@@ -0,0 +1,25 @@
+import 'dart:math';
+
+
+/// Masks a card number, leaving only the last 4 digits visible.
+/// Returns 'N/A' when the input is null or empty.
+String? maskCardNumber(String? pan) {
+  if (pan == null || pan.isEmpty) return null;
+
+  // Strip non-digits to avoid leaking formatting patterns.
+  final digits = pan.replaceAll(RegExp(r'\D'), '');
+  if (digits.length <= 4) return digits;
+
+  final last4 = digits.substring(digits.length - 4);
+  final maskedPrefix = '*' * (digits.length - 4);
+  final masked = '$maskedPrefix$last4';
+
+  // Group into blocks of 4 for readability.
+  final groups = <String>[];
+  for (var i = 0; i < masked.length; i += 4) {
+    final end = min(i + 4, masked.length);
+    groups.add(masked.substring(i, end));
+  }
+
+  return groups.join(' ');
+}