fix(transfer): 修复转让记录 API 路径与参数不匹配

- API 路径: /transfers/my → /transfers（后端无 /my 子路由）
- 分页参数: page/pageSize → limit/offset（匹配后端 DTO）
- 转让记录页显示具体错误信息便于调试

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

frontend/mobile-app/lib/core/services/transfer_service.dart

@@ -13,7 +13,7 @@ import '../network/api_client.dart';
 // - POST /transfers                  发起转让
 // - POST /transfers/:no/confirm      卖方确认
 // - POST /transfers/:no/cancel       取消转让
-// - GET  /transfers/my               我的转让记录
+// - GET  /transfers                   我的转让记录
 // - GET  /transfers/:no              转让详情
 //
 // === 与现有 PlantingService 的关系 ===
@@ -309,10 +309,10 @@ class TransferService {
     try {
       debugPrint('[TransferService] 获取转让记录: role=$role');
       final response = await _apiClient.get(
-        '/transfers/my',
+        '/transfers',
         queryParameters: {
-          'page': page,
-          'pageSize': pageSize,
+          'limit': pageSize,
+          'offset': (page - 1) * pageSize,
           if (role != null) 'role': role,
         },
       );

frontend/mobile-app/lib/features/transfer/presentation/pages/transfer_list_page.dart

@@ -211,6 +211,17 @@ class _TransferListPageState extends ConsumerState<TransferListPage>
               '加载失败',
               style: const TextStyle(color: Color(0xFF5D4037), fontSize: 16),
             ),
+            const SizedBox(height: 4),
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 32),
+              child: Text(
+                _errorMessage ?? '',
+                style: const TextStyle(color: Color(0xFF999999), fontSize: 11),
+                textAlign: TextAlign.center,
+                maxLines: 5,
+                overflow: TextOverflow.ellipsis,
+              ),
+            ),
             const SizedBox(height: 8),
             GestureDetector(
               onTap: _loadData,