fix: 部门出勤/闲置下钻改为基于当日里程区分

- 后端/list新增attendance参数(active/idle)，查询当日里程表区分
  出勤(mileage>0)和闲置(mileage=0)，仅对Operating车辆生效
- 前端部门Tab出勤/闲置点击改用attendance:'active'/'idle'替代
  原来错误的category:'Operating'/'Inventory'
- 修复department='公务车'过滤：匹配departmentName为null的车辆
- 前端API层新增attendance参数传递

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/api.ts

@@ -36,6 +36,7 @@ export async function fetchVehicleList(params: {
   isColdChain?: string;
   isTrailer?: string;
   department?: string;
+  attendance?: string;
 }): Promise<VehicleListItem[]> {
   const query = new URLSearchParams();
   if (params.batch) query.set('batch', params.batch);
@@ -49,6 +50,7 @@ export async function fetchVehicleList(params: {
   if (params.isColdChain) query.set('isColdChain', params.isColdChain);
   if (params.isTrailer) query.set('isTrailer', params.isTrailer);
   if (params.department) query.set('department', params.department);
+  if (params.attendance) query.set('attendance', params.attendance);
   return fetchJson<VehicleListItem[]>(`${BASE}/list?${query.toString()}`);
 }