refactor: Projektstruktur in app/ und backend/ aufgeteilt

app/lib/models/cargo_item.dart

@@ -0,0 +1,99 @@
+class CargoItem {
+  final String id; // Will store the timestamp as string
+  final String jobId; // Will store the timestamp as string
+  final String description;
+  final int quantity;
+  final double weightKg;
+  final double lengthCm;
+  final double widthCm;
+  final double heightCm;
+
+  CargoItem({
+    required this.id,
+    required this.jobId,
+    required this.description,
+    required this.quantity,
+    required this.weightKg,
+    required this.lengthCm,
+    required this.widthCm,
+    required this.heightCm,
+  });
+
+  static String _readString(dynamic value, {String fallback = ''}) {
+    if (value is String) {
+      return value;
+    }
+    if (value is num || value is bool) {
+      return value.toString();
+    }
+    return fallback;
+  }
+
+  factory CargoItem.fromJson(Map<String, dynamic> json) {
+    // Parse the complex id object - can be either a Map or a simple string
+    String idValue = '';
+    if (json['id'] is Map) {
+      final idMap = json['id'] as Map<String, dynamic>;
+      idValue = idMap['timestamp']?.toString() ?? '';
+    } else {
+      idValue = json['id']?.toString() ?? '';
+    }
+
+    // Parse the complex jobId object - can be either a Map or a simple string
+    String jobIdValue = '';
+    if (json['jobId'] is Map) {
+      final jobIdMap = json['jobId'] as Map<String, dynamic>;
+      jobIdValue = jobIdMap['timestamp']?.toString() ?? '';
+    } else {
+      jobIdValue = json['jobId']?.toString() ?? '';
+    }
+
+    return CargoItem(
+      id: idValue,
+      jobId: jobIdValue,
+      description: _readString(json['description']),
+      quantity: json['quantity'] is num ? json['quantity'].toInt() : 0,
+      weightKg: json['weightKg'] is num ? json['weightKg'].toDouble() : 0.0,
+      lengthCm: json['lengthMm'] is num ? json['lengthMm'].toDouble() : 0.0,
+      widthCm: json['widthMm'] is num ? json['widthMm'].toDouble() : 0.0,
+      heightCm: json['heightMm'] is num ? json['heightMm'].toDouble() : 0.0,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'jobId': jobId,
+      'description': description,
+      'quantity': quantity,
+      'weightKg': weightKg,
+      'lengthMm': lengthCm,
+      'widthMm': widthCm,
+      'heightMm': heightCm,
+    };
+  }
+
+  @override
+  String toString() {
+    return 'CargoItem(id: $id, description: $description, quantity: $quantity)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is CargoItem && other.id == id;
+  }
+
+  @override
+  int get hashCode => id.hashCode;
+
+  /// Get formatted dimensions string for display
+  String get formattedDimensions {
+    return '${lengthCm.toInt()} × ${widthCm.toInt()} × ${heightCm.toInt()} cm';
+  }
+
+  /// Get formatted weight string for display
+  String get formattedWeight {
+    return '${weightKg.toStringAsFixed(1)} kg';
+  }
+}