feat(trades): add live execution cockpit, closing cockpit, calculation cards and precision trade settings

FinlyticApp/lib/features/trades/repositories/trade_repository.dart

@@ -3,6 +3,7 @@ import 'package:finlytic_app/core/network/api_client.dart';
 import 'package:finlytic_app/features/trades/models/trade_model.dart';
 import 'package:finlytic_app/features/trades/models/trade_acceptance_dto.dart';
 import 'package:finlytic_app/features/trades/models/close_trade_request_dto.dart';
+import 'package:finlytic_app/features/trades/models/derivative_item_model.dart';
 
 class TradeRepository {
   final ApiClient apiClient;
@@ -29,6 +30,42 @@ class TradeRepository {
     }
   }
 
+  Future<List<DerivativeItemModel>> fetchDerivatives(
+    String isin, {
+    String optionType = 'long',
+    double? targetLeverage,
+    double? minLeverage,
+    double? maxLeverage,
+    String? search,
+    String? after,
+    int? page,
+    bool forceRefresh = false,
+  }) async {
+    try {
+      final queryParams = <String, dynamic>{
+        'optionType': optionType,
+        if (targetLeverage != null && targetLeverage > 0) 'targetLeverage': targetLeverage,
+        if (minLeverage != null) 'minLeverage': minLeverage,
+        if (maxLeverage != null) 'maxLeverage': maxLeverage,
+        if (search != null && search.isNotEmpty) 'search': search,
+        if (after != null && after.isNotEmpty) 'after': after,
+        if (page != null) 'page': page,
+        if (forceRefresh) 'forceRefresh': 'true',
+        '_t': DateTime.now().millisecondsSinceEpoch,
+      };
+
+      final response = await apiClient.get('/api/v1/assets/$isin/derivatives', queryParameters: queryParams);
+
+      if (response.statusCode == 200 && response.data != null) {
+        final List<dynamic> data = response.data;
+        return data.map((json) => DerivativeItemModel.fromJson(json)).toList();
+      }
+      return [];
+    } catch (e) {
+      throw Exception('Derivate konnten nicht geladen werden: $e');
+    }
+  }
+
   Future<void> acceptTrade(TradeAcceptanceDto dto) async {
     final response = await apiClient.post('/api/v1/user/trades/accept', data: dto.toJson());
     if (response.statusCode != 200) {
@@ -50,3 +87,4 @@ class TradeRepository {
     }
   }
 }
+