退款审核功能：待交接取消不再自动退款，改为客服审核后原路退回

- 租客在待交接状态取消订单不再自动退款，改为 refund_status=pending_review
- 新增退款审核页面 /admin/orders/refund-review，客服可逐个审核
- 新增 POST /refund/approve 通过退款、POST /refund/reject 驳回退款
- 新增 GET /orders/refund-pending 查询待审核退款订单列表
- 优化状态标签表述：已取消→租客已取消、已关闭→客服已关闭、异常→客服介入
- 新增 refund_status: pending_review 及其前端标签「待客服审核退款」
- AdminOrderDetailView 退款状态改用统一 refundStatusLabel

backend/internal/modules/order/refund_review.go

@@ -0,0 +1,28 @@
+package order
+
+import (
+	"context"
+)
+
+// ListPendingRefund 查询所有待客服审核退款的订单。
+func (r *Repository) ListPendingRefund(ctx context.Context) ([]OrderDTO, error) {
+	var rows []orderRow
+	err := r.adminQuery(ctx).
+		Where("o.refund_status = ?", refundStatusPendingReview).
+		Order("o.updated_at ASC, o.id ASC").
+		Limit(200).
+		Scan(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+
+	db := r.db.WithContext(ctx)
+	paymentTimeoutMinutes := pendingPaymentTimeoutMinutes(db)
+	items := make([]OrderDTO, 0, len(rows))
+	for _, row := range rows {
+		dto := row.toAdminDTO()
+		applyPaymentDeadline(&dto, row.RentalOrder, paymentTimeoutMinutes)
+		items = append(items, dto)
+	}
+	return items, nil
+}