perf: 实时监控性能优化

- 后端：车辆关联信息缓存5分钟、两库并行查询、支持服务端
  筛选/排序/分页（默认返回100条）
- 前端：筛选和排序参数传给后端，不再加载全量数据
- 筛选选项（部门/客户/车牌）仅首次加载获取

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

src/modules/mileage/api.ts

@@ -8,8 +8,25 @@ async function fetchJson<T>(url: string): Promise<T> {
   return res.json();
 }
 
-export async function fetchMonitoring(): Promise<MonitoringData> {
-  return fetchJson<MonitoringData>(`${BASE}/monitoring`);
+export async function fetchMonitoring(params?: {
+  sortBy?: string;
+  sortOrder?: string;
+  limit?: number;
+  offset?: number;
+  search?: string;
+  dept?: string;
+  customer?: string;
+}): Promise<MonitoringData> {
+  const query = new URLSearchParams();
+  if (params?.sortBy) query.set('sortBy', params.sortBy);
+  if (params?.sortOrder) query.set('sortOrder', params.sortOrder);
+  if (params?.limit) query.set('limit', String(params.limit));
+  if (params?.offset) query.set('offset', String(params.offset));
+  if (params?.search) query.set('search', params.search);
+  if (params?.dept) query.set('dept', params.dept);
+  if (params?.customer) query.set('customer', params.customer);
+  const qs = query.toString();
+  return fetchJson<MonitoringData>(`${BASE}/monitoring${qs ? `?${qs}` : ''}`);
 }
 
 export async function fetchTargets(): Promise<TargetSummary[]> {