feat: extend boxing page for accessory boxing support

Add pending accessories section to both single-code and multi-code boxing
modes. Accessories display with orange styling and a "加入本箱" button that
calls saveBoxRecord with item_type=accessory. Extend API service with
PendingAccessory model, itemType fields on data classes, and optional
accessory_id parameter on saveBoxRecord. Show accessories with visual
indicator (wrench icon + orange background) in boxing detail page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/services/api_service.dart

@@ -118,6 +118,30 @@ class PaichaOverviewResult {
 
 // === 装箱模块数据类 ===
 
+/// 待装箱附件
+class PendingAccessory {
+  final int accessoryId;
+  final String accessoryType;
+  final int quantity;
+  final String? locationCode;
+
+  PendingAccessory({
+    required this.accessoryId,
+    required this.accessoryType,
+    required this.quantity,
+    this.locationCode,
+  });
+
+  factory PendingAccessory.fromJson(Map<String, dynamic> json) {
+    return PendingAccessory(
+      accessoryId: json['accessory_id'] as int,
+      accessoryType: json['accessory_type'] as String,
+      quantity: json['quantity'] as int,
+      locationCode: json['location_code']?.toString(),
+    );
+  }
+}
+
 /// 箱号内单个总排号明细
 class BoxItemData {
   final int? boxItemId;
@@ -125,6 +149,7 @@ class BoxItemData {
   final String? workOrderNo;
   final int quantity;
   final int? totalQuantity;
+  final String itemType;
 
   BoxItemData({
     this.boxItemId,
@@ -132,6 +157,7 @@ class BoxItemData {
     this.workOrderNo,
     required this.quantity,
     this.totalQuantity,
+    this.itemType = 'product',
   });
 
   factory BoxItemData.fromJson(Map<String, dynamic> json) {
@@ -141,6 +167,7 @@ class BoxItemData {
       workOrderNo: json['work_order_no']?.toString(),
       quantity: json['quantity'] as int,
       totalQuantity: json['total_quantity'] as int?,
+      itemType: json['item_type'] as String? ?? 'product',
     );
   }
 }
@@ -167,11 +194,13 @@ class CurrentZongpaiBoxData {
   final int boxItemId;
   final int boxNo;
   final int quantity;
+  final String itemType;
 
   CurrentZongpaiBoxData({
     required this.boxItemId,
     required this.boxNo,
     required this.quantity,
+    this.itemType = 'product',
   });
 
   factory CurrentZongpaiBoxData.fromJson(Map<String, dynamic> json) {
@@ -179,6 +208,7 @@ class CurrentZongpaiBoxData {
       boxItemId: json['box_item_id'] as int,
       boxNo: json['box_no'] as int,
       quantity: json['quantity'] as int,
+      itemType: json['item_type'] as String? ?? 'product',
     );
   }
 }
@@ -195,7 +225,7 @@ class BoxInfoResult {
   final List<BoxDetailData> existingBoxes;
   final int maxBoxNo;
   final int suggestedBoxNo;
-  final int pendingAccessories;
+  final List<PendingAccessory> pendingAccessories;
 
   BoxInfoResult({
     required this.success,
@@ -208,7 +238,7 @@ class BoxInfoResult {
     this.existingBoxes = const [],
     this.maxBoxNo = 0,
     this.suggestedBoxNo = 1,
-    this.pendingAccessories = 0,
+    this.pendingAccessories = const [],
   });
 
   factory BoxInfoResult.ok(Map<String, dynamic> json) {
@@ -224,6 +254,11 @@ class BoxInfoResult {
             )
             .toList() ??
         [];
+    final pendingAccessories =
+        (json['pending_accessories'] as List<dynamic>?)
+            ?.map((a) => PendingAccessory.fromJson(a as Map<String, dynamic>))
+            .toList() ??
+        [];
     return BoxInfoResult(
       success: true,
       zongpaiNo: json['zongpai_no'] as String?,
@@ -234,7 +269,7 @@ class BoxInfoResult {
       existingBoxes: boxes,
       maxBoxNo: json['max_box_no'] as int? ?? 0,
       suggestedBoxNo: json['suggested_box_no'] as int? ?? 1,
-      pendingAccessories: json['pending_accessories'] as int? ?? 0,
+      pendingAccessories: pendingAccessories,
     );
   }
 
@@ -583,18 +618,25 @@ class ApiService {
     required String zongpaiNo,
     required int boxNo,
     required int quantity,
+    String itemType = 'product',
+    int? accessoryId,
   }) async {
     final uri = Uri.parse('$baseUrl/CargoTrace/box');
     try {
+      final bodyMap = <String, dynamic>{
+        'zongpai_no': zongpaiNo,
+        'box_no': boxNo,
+        'quantity': quantity,
+        'item_type': itemType,
+      };
+      if (accessoryId != null) {
+        bodyMap['accessory_id'] = accessoryId;
+      }
       final response = await _client
           .post(
             uri,
             headers: {'Content-Type': 'application/json'},
-            body: jsonEncode({
-              'zongpai_no': zongpaiNo,
-              'box_no': boxNo,
-              'quantity': quantity,
-            }),
+            body: jsonEncode(bodyMap),
           )
           .timeout(timeout);