接单平台分类管理完善：抢单大厅分类筛选与分类 CRUD

- 抢单大厅新增分类 Tab 筛选（仅显示启用分类，支持按分类查询工单）
- 管理端分类面板支持编辑、启用/停用切换、删除（被工单/规则引用时禁止删除）
- 后端工单列表支持 categoryId 筛选，大厅接口返回分类列表

apps/backend/src/routes/admin/worker-platform.ts

@@ -4,6 +4,7 @@ import {
   acceptAdminWorkOrder,
   creditAdminWorkerWallet,
   createAdminMockWorkOrder,
+  deleteAdminWorkCategory,
   getAdminWorkerFinanceConfig,
   getAdminWorkerPlatformSummary,
   listAdminWorkerFinanceRequests,
@@ -92,6 +93,22 @@ router.post(
   }),
 )
 
+router.delete(
+  '/worker-platform/categories/:categoryId',
+  requireAdminRoles(['admin', 'operator']),
+  createJsonHandler((req) => deleteAdminWorkCategory(String(req.params.categoryId || '')), {
+    successMessage: '接单分类已删除',
+    errorMessage: '删除接单分类失败',
+    scope: '[admin/worker-platform/categories/:categoryId]',
+    audit: (_req, data) => ({
+      action: 'work_category_deleted',
+      targetType: 'work_category',
+      targetId: String(_req.params.categoryId || ''),
+      data: data && typeof data === 'object' ? (data as Record<string, unknown>) : {},
+    }),
+  }),
+)
+
 router.get(
   '/worker-platform/product-rules',
   requireAdminRoles(['admin', 'operator', 'support']),