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/repositories/worker-platform-repo.ts

@@ -166,6 +166,7 @@ type ListInput = {
   status?: string
   keyword?: string
   workerId?: number
+  categoryId?: number
 }
 
 type ProductRuleListInput = {
@@ -912,6 +913,14 @@ export async function getWorkCategoryByKey(categoryKey: string): Promise<WorkCat
   return result.rows[0] || null
 }
 
+export async function getWorkCategoryById(categoryId: number | string): Promise<WorkCategoryRow | null> {
+  const result = await query<WorkCategoryRow>(
+    'SELECT * FROM work_categories WHERE id = $1 LIMIT 1',
+    [Number(categoryId)],
+  )
+  return result.rows[0] || null
+}
+
 export async function listWorkCategories(): Promise<WorkCategoryRow[]> {
   const result = await query<WorkCategoryRow>(
     `SELECT * FROM work_categories WHERE status = 'active' ORDER BY sort_order ASC, id ASC`,
@@ -946,6 +955,36 @@ export async function upsertWorkCategory(input: {
   return result.rows[0] || null
 }
 
+export async function countWorkCategoryUsages(categoryId: number | string): Promise<{
+  workOrderCount: number
+  productRuleCount: number
+}> {
+  const [orders, rules] = await Promise.all([
+    query<{ total: number }>(
+      'SELECT COUNT(*)::int AS total FROM work_orders WHERE category_id = $1',
+      [Number(categoryId)],
+    ),
+    query<{ total: number }>(
+      'SELECT COUNT(*)::int AS total FROM work_product_rules WHERE category_id = $1',
+      [Number(categoryId)],
+    ),
+  ])
+  return {
+    workOrderCount: Number(orders.rows[0]?.total || 0),
+    productRuleCount: Number(rules.rows[0]?.total || 0),
+  }
+}
+
+export async function deleteWorkCategory(
+  categoryId: number | string,
+): Promise<{ deleted: boolean }> {
+  const result = await query<{ id: number }>(
+    'DELETE FROM work_categories WHERE id = $1 RETURNING id',
+    [Number(categoryId)],
+  )
+  return { deleted: Boolean(result.rows[0]) }
+}
+
 export async function listWorkProductRules({
   enabled = null,
   keyword = '',
@@ -1123,8 +1162,14 @@ export async function listWorkOrders({
   status = '',
   keyword = '',
   workerId = 0,
+  categoryId = 0,
 }: ListInput = {}): Promise<{ items: WorkOrderRow[]; total: number }> {
-  const { whereClause, params } = buildWorkOrderWhere({ status, keyword, workerId })
+  const { whereClause, params } = buildWorkOrderWhere({
+    status,
+    keyword,
+    workerId,
+    categoryId,
+  })
   const totalResult = await query<{ total: number }>(
     `
       SELECT COUNT(*)::int AS total
@@ -1713,7 +1758,12 @@ function buildWorkerUserWhere({
   }
 }
 
-function buildWorkOrderWhere({ status = '', keyword = '', workerId = 0 }: ListInput) {
+function buildWorkOrderWhere({
+  status = '',
+  keyword = '',
+  workerId = 0,
+  categoryId = 0,
+}: ListInput) {
   const filters: string[] = []
   const params: unknown[] = []
   if (status) {
@@ -1730,6 +1780,10 @@ function buildWorkOrderWhere({ status = '', keyword = '', workerId = 0 }: ListIn
     params.push(workerId)
     filters.push(`wo.assigned_worker_id = $${params.length}`)
   }
+  if (categoryId) {
+    params.push(categoryId)
+    filters.push(`wo.category_id = $${params.length}`)
+  }
   return {
     whereClause: filters.length > 0 ? `WHERE ${filters.join(' AND ')}` : '',
     params,