拆分接单平台超长文件，按域组织代码

- worker-platform-service.ts (2733行) 拆为 worker-service/admin-service/mappers + index 聚合
- worker-platform-repo.ts (2456行) 拆为 repositories/worker-platform/ 目录（types/shared/worker-repo/work-order-repo）
- AdminWorkerPlatformPage.tsx (2784行) 拆为主页面 + panels/ 目录（7 个面板文件）
- 引用方统一改指向 index 聚合，行为不变

apps/backend/src/services/platforms/ninetyone/order-service.ts

@@ -11,7 +11,7 @@ import {
 } from '../../../repositories/order-item-repo.js'
 import { listTasksByOrderId } from '../../../repositories/task-repo.js'
 import { upsertOrderFromSource } from '../../order/order-service.js'
-import { syncWorkerOrdersForSourceOrder } from '../../worker-platform/worker-platform-service.js'
+import { syncWorkerOrdersForSourceOrder } from '../../worker-platform/index.js'
 import { bindKuaishouIndustryVouchersToOrderTasks } from '../kuaishou-industry/voucher-binding-service.js'
 import { asJsonObject, type JsonObject } from '../../../types/json.js'
 import { OPEN_91_PLATFORM, OPEN_91_PROVIDER } from '../../open-91/config.js'