fix(distribution): 修复收号站订单详情权限、专属支付通道路由、大盘统计与仲裁积分隔离

- 修复 FindOrder 在收号站模式(two_party_distributor_receive / three_party)下的 403 权限判定，放行参与方站点成员并精准计算收益
- 串联 distribution_site_payment_channels 至 payment.Start 核心支付发起流程，分销订单优先使用绑定的专属商户通道
- 修复数据大盘 GetDashboardAnalytics 趋势中 ReceivedCount 恒为 0 的问题，并对齐今日订单与 GMV 统计
- 修复 dispute/arbitration.go 仲裁完成时向分销租客发放成长积分的泄漏风险
- 提现管理新增 distribution_site_name/distribution_site_code 字段并在后台列表与详情弹窗中区分展示分销站
- GetPublicSiteInfo 增加 X-Distribution-Site-Code 请求头兜底支持

backend/internal/modules/withdrawal/presenter.go

@@ -75,12 +75,23 @@ func (r *Repository) toDetailDTO(ctx context.Context, w model.WithdrawalRequest)
 		}
 	}
 
+	var siteName, siteCode string
+	if w.DistributionSiteID > 0 {
+		var site model.DistributionSite
+		if err := db.Select("site_name, site_code").First(&site, w.DistributionSiteID).Error; err == nil {
+			siteName = site.SiteName
+			siteCode = site.SiteCode
+		}
+	}
+
 	return &WithdrawalDetailDTO{
-		ID:                 w.ID,
-		WithdrawNo:         w.WithdrawNo,
-		UserID:             w.UserID,
-		DistributionSiteID: w.DistributionSiteID,
-		UserNickname:       user.Nickname,
+		ID:                   w.ID,
+		WithdrawNo:           w.WithdrawNo,
+		UserID:               w.UserID,
+		DistributionSiteID:   w.DistributionSiteID,
+		DistributionSiteName: siteName,
+		DistributionSiteCode: siteCode,
+		UserNickname:         user.Nickname,
 		UserPhone:          user.Phone,
 		AmountCent:         w.AmountCent,
 		FeeCent:            w.FeeCent,