feat(finance): 自动发货订单项按上游 SKU 直接归一

自动发货只有 affiliate-dash 单一上游渠道，订单项直接按 fulfillment_tasks.context_json.skuCode 归一为 aff:<skuCode>，不写 channel_product_mappings。\n\n新增 /cost-center/affiliate-products/backfill：按 order_item_id 取最新任务 SKU 回填 canonical_product_id，只更新有变化的订单项，并自动重算受影响日期的销售事实；返回 updatedCount/skippedCount/remainingCount。\n\n自动发货 SKU 列表改为实时统计履约任务数与最近履约时间，不读会被价格导入覆盖的 attributes_json。\n\n本地实测 41,676 个订单项全部归一，自动发货未归一收入 5,089,712.26 元降至 0；整体未归一占比 79.67% 降至 60.47%。

apps/backend/src/routes/admin/cost-center.ts

@@ -3,6 +3,7 @@ import { Router } from 'express'
 
 import {
   applyAdminTemplateProductBootstrap,
+  backfillAdminAffiliateDashSkus,
   backfillAdminNormalizedQuantities,
   backfillAdminProductMappings,
   createAdminChannelMapping,
@@ -116,6 +117,22 @@ router.post(
   }),
 )
 
+router.post(
+  '/cost-center/affiliate-products/backfill',
+  requireAdminPermission('finance.config'),
+  createJsonHandler(() => backfillAdminAffiliateDashSkus(), {
+    successMessage: '自动发货 SKU 已回填',
+    errorMessage: '回填自动发货 SKU 失败',
+    scope: '[admin/cost-center/affiliate-products/backfill]',
+    audit: (_req, data) => ({
+      action: 'cost_affiliate_skus_backfilled',
+      targetType: 'order_items',
+      targetId: '',
+      data: data as Record<string, unknown>,
+    }),
+  }),
+)
+
 router.get(
   '/cost-center/products',
   requireAdminPermission('finance.view'),