feat: IoT卡新增绑定设备虚拟号快照字段

- tb_iot_card 新增 device_virtual_no 字段，存储绑定设备的虚拟号快照
- 列表/详情接口响应新增 device_virtual_no 字段
- 列表接口 is_standalone 改为可选参数（不传返回全部卡）
- 移除列表接口 virtual_no 查询参数
- 绑卡/解绑时同步更新 device_virtual_no 快照
- 设备导入时批量写入 device_virtual_no 快照
- 归档 feat-iot-card-device-virtual-no 变更提案

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

internal/service/iot_card/service.go

@@ -124,8 +124,8 @@ func (s *Service) ListStandalone(ctx context.Context, req *dto.ListStandaloneIot
 	if req.MSISDN != "" {
 		filters["msisdn"] = req.MSISDN
 	}
-	if req.VirtualNo != "" {
-		filters["virtual_no"] = req.VirtualNo
+	if req.IsStandalone != nil {
+		filters["is_standalone"] = req.IsStandalone
 	}
 	if req.BatchNo != "" {
 		filters["batch_no"] = req.BatchNo
@@ -279,6 +279,7 @@ func (s *Service) toStandaloneResponse(card *model.IotCard, shopMap map[uint]str
 		SeriesID:              card.SeriesID,
 		FirstCommissionPaid:   card.FirstCommissionPaid,
 		AccumulatedRecharge:   card.AccumulatedRecharge,
+		DeviceVirtualNo:       card.DeviceVirtualNo,
 		CreatedAt:             card.CreatedAt,
 		UpdatedAt:             card.UpdatedAt,
 	}