feat(退款): AUG26-006 退款方式选择与原路退款

按 PRD 2.3/2.4/2.5 落地套餐退款的方式矩阵与原路渠道退款：

- 退款申请派生并冻结权威实收金额（线上取原成功支付记录，钱包/线下取订单实际收款），
  提交人不可填写或修改；按来源支付方式生成可选方式矩阵并在创建、提交、执行前重复校验。
- 审批切换为「每次提交一条不可变审批尝试记录 + 独立企业微信审批实例」，业务标识取尝试
  记录主键；终态消费按尝试记录优先、退款申请兜底双读，兼容存量无实例与已关联实例申请。
  新增活动退款部分唯一索引 (order_id) WHERE status IN (1,5,6)。
- 本地人工终审保持既有开关，补齐通过入口的 approval_instance_id IS NULL 守卫，使三个
  入口一致拒绝已关联审批实例的申请；重提按尝试模式重写（仅已拒绝/已退回/原路失败且无异常）。
- 权益时点：企微通过事务写退款终态、按方式确定的订单态、钱包回款、员工账单冲销与可靠
  失效事实；套餐失效/接续/停机仍由既有可靠机制最终一致执行，不把外部调用放入资金事务。
  订单支付状态按方式置位：凭证退款与退回原钱包在企微通过时置已退款，原路须渠道明确成功。
- 按官方契约实现微信直连 v3、微信 v2（双向证书）、富友（/commonRefund 与 /refundQuery）、
  支付宝四类原路退款；能力只由服务商类型与退款必需凭证完整性决定，无人工开关。
  渠道请求号在提交时冻结到尝试记录，并以 channel_submitted_at 条件认领保证资金动作至多
  提交一次（重复投递只查询不二次提交）；不向任何渠道传递退款结果通知地址。
- 新增 refund:channel:recovery 恢复任务只查询回填；本地查询窗口超期（富友 72 小时、
  微信 v2 7 天）转原路退款失败、渠道状态已失败、分类超时未知并置异常转人工，不放行自动
  重提以避免重复退款。
- 同步退款 DTO/导出/审计资源与审计查询关联、商户凭证文档，并修正 fuiou 集成契约文档。

迁移 000218（退款尝试与渠道退款事实）、000219（微信 v2 客户端证书凭证）成对提供，
未修改既有迁移；测试库 junhong_cmp_test 完成 up/down/up 与行为核对，未调用真实渠道。

internal/exporter/refund_scene.go

@@ -39,7 +39,9 @@ func (s *RefundDataSource) Count(ctx context.Context, params ExportParams) (int,
 func (s *RefundDataSource) Headers(context.Context, ExportParams) ([]string, error) {
 	return []string{
 		"退款单号", "代理店铺名称", "关联的支付订单号", "资产类型", "资产标识", "套餐名称", "原订单金额(元)",
-		"实收金额(元)", "可退金额(元)", "申请退款金额(元)", "实际退款金额(元)", "状态", "退款原因", "审批备注",
+		"实收金额(元)", "可退金额(元)", "申请退款金额(元)", "实际退款金额(元)", "状态", "退款方式",
+		"冻结实收金额(元)", "渠道退款状态", "渠道退款流水号", "渠道退款金额(元)", "失败分类", "异常标记",
+		"退款原因", "审批备注",
 		"审批来源", "审批状态", "退款处理状态", "退款申请时间", "退款审批时间", "提交人", "退款凭证",
 	}, nil
 }
@@ -61,6 +63,13 @@ func (s *RefundDataSource) Fetch(ctx context.Context, params ExportParams, offse
 			r.requested_refund_amount,
 			r.approved_refund_amount,
 			r.status,
+			r.method,
+			r.frozen_actual_received_amount,
+			r.channel_refund_status,
+			r.channel_refund_no,
+			r.channel_refund_amount,
+			r.failure_reason,
+			r.anomaly_flag,
 			r.refund_reason,
 			r.remark,
 			r.commission_deducted,
@@ -109,6 +118,13 @@ func (s *RefundDataSource) Fetch(ctx context.Context, params ExportParams, offse
 			formatMoneyYuan(item.RequestedRefundAmount),
 			formatOptionalMoneyYuan(item.ApprovedRefundAmount),
 			constants.GetRefundStatusName(item.Status),
+			constants.RefundMethodName(item.Method),
+			formatMoneyYuan(item.FrozenActualReceivedAmount),
+			constants.RefundChannelStatusName(item.ChannelRefundStatus),
+			item.ChannelRefundNo,
+			formatMoneyYuan(item.ChannelRefundAmount),
+			constants.RefundFailureReasonName(item.FailureReason),
+			formatRefundAnomalyFlag(item.AnomalyFlag),
 			item.RefundReason,
 			item.Remark,
 			formatRefundApprovalSource(item.ApprovalProvider),
@@ -145,28 +161,35 @@ func (s *RefundDataSource) applyFilters(query *gorm.DB, params ExportParams) *go
 }
 
 type refundExportRow struct {
-	RefundNo              string     `gorm:"column:refund_no"`
-	ShopName              string     `gorm:"column:shop_name"`
-	OrderNo               string     `gorm:"column:order_no"`
-	OrderType             string     `gorm:"column:order_type"`
-	AssetIdentifier       string     `gorm:"column:asset_identifier"`
-	PackageName           string     `gorm:"column:package_name"`
-	OriginalAmount        *int64     `gorm:"column:original_amount"`
-	ActualReceivedAmount  int64      `gorm:"column:actual_received_amount"`
-	RefundableAmount      *int64     `gorm:"column:refundable_amount"`
-	RequestedRefundAmount int64      `gorm:"column:requested_refund_amount"`
-	ApprovedRefundAmount  *int64     `gorm:"column:approved_refund_amount"`
-	Status                int        `gorm:"column:status"`
-	RefundReason          string     `gorm:"column:refund_reason"`
-	Remark                string     `gorm:"column:remark"`
-	ApprovalProvider      *string    `gorm:"column:approval_provider"`
-	ApprovalStatus        *int       `gorm:"column:approval_status"`
-	CommissionDeducted    bool       `gorm:"column:commission_deducted"`
-	AssetReset            bool       `gorm:"column:asset_reset"`
-	CreatedAt             time.Time  `gorm:"column:created_at"`
-	ProcessedAt           *time.Time `gorm:"column:processed_at"`
-	SubmitterName         string     `gorm:"column:submitter_name"`
-	VoucherKeys           string     `gorm:"column:voucher_keys"`
+	RefundNo                   string     `gorm:"column:refund_no"`
+	ShopName                   string     `gorm:"column:shop_name"`
+	OrderNo                    string     `gorm:"column:order_no"`
+	OrderType                  string     `gorm:"column:order_type"`
+	AssetIdentifier            string     `gorm:"column:asset_identifier"`
+	PackageName                string     `gorm:"column:package_name"`
+	OriginalAmount             *int64     `gorm:"column:original_amount"`
+	ActualReceivedAmount       int64      `gorm:"column:actual_received_amount"`
+	RefundableAmount           *int64     `gorm:"column:refundable_amount"`
+	RequestedRefundAmount      int64      `gorm:"column:requested_refund_amount"`
+	ApprovedRefundAmount       *int64     `gorm:"column:approved_refund_amount"`
+	Status                     int        `gorm:"column:status"`
+	Method                     string     `gorm:"column:method"`
+	FrozenActualReceivedAmount int64      `gorm:"column:frozen_actual_received_amount"`
+	ChannelRefundStatus        int        `gorm:"column:channel_refund_status"`
+	ChannelRefundNo            string     `gorm:"column:channel_refund_no"`
+	ChannelRefundAmount        int64      `gorm:"column:channel_refund_amount"`
+	FailureReason              string     `gorm:"column:failure_reason"`
+	AnomalyFlag                int        `gorm:"column:anomaly_flag"`
+	RefundReason               string     `gorm:"column:refund_reason"`
+	Remark                     string     `gorm:"column:remark"`
+	ApprovalProvider           *string    `gorm:"column:approval_provider"`
+	ApprovalStatus             *int       `gorm:"column:approval_status"`
+	CommissionDeducted         bool       `gorm:"column:commission_deducted"`
+	AssetReset                 bool       `gorm:"column:asset_reset"`
+	CreatedAt                  time.Time  `gorm:"column:created_at"`
+	ProcessedAt                *time.Time `gorm:"column:processed_at"`
+	SubmitterName              string     `gorm:"column:submitter_name"`
+	VoucherKeys                string     `gorm:"column:voucher_keys"`
 }
 
 func formatRefundAssetType(orderType string) string {
@@ -200,7 +223,19 @@ func formatRefundProcessingStatus(status int, commissionDeducted, assetReset boo
 			return "已完成"
 		}
 		return "处理中"
+	case model.RefundStatusChannelProcessing:
+		return "原路退款处理中"
+	case model.RefundStatusChannelFailed:
+		return "原路退款失败待人工处理"
 	default:
 		return "未知"
 	}
 }
+
+// formatRefundAnomalyFlag 将异常标记转为导出用中文描述。
+func formatRefundAnomalyFlag(flag int) string {
+	if flag == 0 {
+		return "无异常"
+	}
+	return "有异常"
+}