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/frontend/src/services/admin/cost-center.ts

@@ -52,6 +52,23 @@ export function syncAdminAffiliateDashProducts() {
   )
 }
 
+export function backfillAdminAffiliateDashSkus() {
+  return apiPost<{
+    updatedCount: number
+    skippedCount: number
+    remainingCount: number
+    affiliateItemCount: number
+    matchedCount: number
+    factsRebuild: {
+      fromDate: string
+      toDate: string
+      deletedCount: number
+      insertedCount: number
+      batchCount: number
+    } | null
+  }>('/api/v1/admin/cost-center/affiliate-products/backfill')
+}
+
 export function updateAdminProductCatalog(productId: number, payload: Record<string, unknown>) {
   return apiPatch<{ product: ProductCatalogItem }>(
     `/api/v1/admin/cost-center/products/${productId}`,