fix: 修复微信发货接口 UTF8 编码问题

- 使用字符串模板直接构建 JSON，与 PHP 实现保持一致
- 移除 JsonSerializer 的 SnakeCaseLower 策略避免双重转换
- 添加请求内容的调试日志

server/HoneyBox/src/HoneyBox.Core/Services/WechatService.cs

@@ -1013,38 +1013,35 @@ public class WechatService : IWechatService
                 };
             }
 
-            // 4. 构建请求参数
+            // 4. 构建请求参数 - 直接构建 JSON 字符串，与 PHP 保持一致
             var itemDesc = request.ItemDesc ?? GetDefaultItemDesc(request.OrderNo);
             var uploadTime = DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss") + "+08:00";
 
-            var requestBody = new
-            {
-                order_key = new
+            // 使用字符串模板构建 JSON，确保格式与微信要求一致
+            var jsonContent = $$"""
                 {
-                    order_number_type = 1, // 使用商户订单号
-                    mchid = mchId,
-                    out_trade_no = request.OrderNo
-                },
-                logistics_type = request.LogisticsType, // 4=虚拟商品
-                delivery_mode = 1, // 1=统一发货
-                shipping_list = new[]
-                {
-                    new { item_desc = itemDesc }
-                },
-                upload_time = uploadTime,
-                payer = new
-                {
-                    openid = request.OpenId
+                    "order_key": {
+                        "order_number_type": 1,
+                        "mchid": "{{mchId}}",
+                        "out_trade_no": "{{request.OrderNo}}"
+                    },
+                    "logistics_type": {{request.LogisticsType}},
+                    "delivery_mode": 1,
+                    "shipping_list": [
+                        {
+                            "item_desc": "{{itemDesc}}"
+                        }
+                    ],
+                    "upload_time": "{{uploadTime}}",
+                    "payer": {
+                        "openid": "{{request.OpenId}}"
+                    }
                 }
-            };
-
-            var jsonContent = JsonSerializer.Serialize(requestBody, new JsonSerializerOptions
-            {
-                PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower
-            });
+                """;
 
             _logger.LogInformation("调用微信发货接口: OrderNo={OrderNo}, MchId={MchId}, OpenId={OpenId}",
                 request.OrderNo, mchId, request.OpenId);
+            _logger.LogDebug("发货请求内容: {JsonContent}", jsonContent);
 
             // 5. 发送请求
             var url = $"{uploadShippingUrl}?access_token={accessToken}";