implemented backend wallet service connection

frontend/pweb/lib/services/wallets.dart

@@ -1,33 +1,28 @@
+import 'package:pshared/service/wallet.dart' as shared_wallet_service;
+
 import 'package:pweb/models/currency.dart';
 import 'package:pweb/models/wallet.dart';
+import 'package:pweb/data/mappers/wallet_ui.dart';
 
 
 abstract class WalletsService {
-  Future<List<Wallet>> getWallets();
-  Future<double> getBalance(String walletRef);
+  Future<List<Wallet>> getWallets(String organizationRef);
+  Future<double> getBalance(String organizationRef, String walletRef);
 }
 
 class MockWalletsService implements WalletsService {
   final List<Wallet> _wallets = [
-    Wallet(id: '1124', walletUserID: 'WA-12345667', name: 'Main Wallet', balance: 10000000.0, currency: Currency.rub),
-    Wallet(id: '2124', walletUserID: 'WA-76654321', name: 'Savings', balance: 2500.5, currency: Currency.usd),
+    Wallet(id: '1124', walletUserID: 'WA-12345667', name: 'Main Wallet', balance: 10000000.0, currency: Currency.rub, calculatedAt: DateTime.now()),
+    Wallet(id: '2124', walletUserID: 'WA-76654321', name: 'Savings', balance: 2500.5, currency: Currency.usd, calculatedAt: DateTime.now()),
   ];
 
   @override
-  Future<List<Wallet>> getWallets() async {
+  Future<List<Wallet>> getWallets(String _) async {
     return _wallets;
   }
 
   @override
-  Future<Wallet> getWallet(String walletId) async {
-    return _wallets.firstWhere(
-      (wallet) => wallet.id == walletId,
-      orElse: () => throw Exception('Wallet not found'),
-    );
-  }
-
-  @override
-  Future<double> getBalance(String walletRef) async {
+  Future<double> getBalance(String _, String walletRef) async {
     final wallet = _wallets.firstWhere(
       (w) => w.id == walletRef,
       orElse: () => throw Exception('Wallet not found'),
@@ -35,3 +30,21 @@ class MockWalletsService implements WalletsService {
     return wallet.balance;
   }
 }
+
+class ApiWalletsService implements WalletsService {
+  @override
+  Future<List<Wallet>> getWallets(String organizationRef) async {
+    final models = await shared_wallet_service.WalletService.list(organizationRef);
+    return models.map((m) => m.toUi()).toList();
+  }
+
+  @override
+  Future<double> getBalance(String organizationRef, String walletRef) async {
+    final balance = await shared_wallet_service.WalletService.getBalance(
+      organizationRef: organizationRef,
+      walletRef: walletRef,
+    );
+    final amount = balance.available?.amount;
+    return amount == null ? 0 : double.tryParse(amount) ?? 0;
+  }
+}