feat: 资产总览新增所属公司筛选，支持按归属主体过滤全页数据

- 后端：新增 /api/vehicles/subjects 端点返回公司列表+台数预览；所有聚合端点接受 ?subject= 参数按 tab_truck.org_id 对应的主体公司过滤
- 前端：标题下方新增 Scope Chip 单选下拉，支持搜索+台数预览，选中后全页 KPI/汇总/库存统计按公司联动刷新

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

src/modules/assets/api.ts

@@ -11,12 +11,29 @@ import { fetchJson } from '../../auth/api-client';
 
 const BASE = '/api/vehicles';
 
-export async function fetchSummary(): Promise<SummaryData> {
-  return fetchJson<SummaryData>(`${BASE}/summary`);
+export interface SubjectOption {
+  name: string;
+  total: number;
+  inventory: number;
+  operating: number;
 }
 
-export async function fetchByType(): Promise<TypeSummary[]> {
-  return fetchJson<TypeSummary[]>(`${BASE}/by-type`);
+function withSubject(path: string, subject?: string | null): string {
+  if (!subject) return path;
+  const sep = path.includes('?') ? '&' : '?';
+  return `${path}${sep}subject=${encodeURIComponent(subject)}`;
+}
+
+export async function fetchSubjects(): Promise<SubjectOption[]> {
+  return fetchJson<SubjectOption[]>(`${BASE}/subjects`);
+}
+
+export async function fetchSummary(subject?: string | null): Promise<SummaryData> {
+  return fetchJson<SummaryData>(withSubject(`${BASE}/summary`, subject));
+}
+
+export async function fetchByType(subject?: string | null): Promise<TypeSummary[]> {
+  return fetchJson<TypeSummary[]>(withSubject(`${BASE}/by-type`, subject));
 }
 
 export async function fetchVehicleList(params: {
@@ -32,6 +49,7 @@ export async function fetchVehicleList(params: {
   isTrailer?: string;
   department?: string;
   attendance?: string;
+  subject?: string | null;
 }): Promise<VehicleListItem[]> {
   const query = new URLSearchParams();
   if (params.batch) query.set('batch', params.batch);
@@ -46,6 +64,7 @@ export async function fetchVehicleList(params: {
   if (params.isTrailer) query.set('isTrailer', params.isTrailer);
   if (params.department) query.set('department', params.department);
   if (params.attendance) query.set('attendance', params.attendance);
+  if (params.subject) query.set('subject', params.subject);
   return fetchJson<VehicleListItem[]>(`${BASE}/list?${query.toString()}`);
 }
 
@@ -57,29 +76,40 @@ export interface WeeklyDetailItem {
   customer_name: string | null;
 }
 
-export async function fetchDeptStats(): Promise<DeptGroup[]> {
-  return fetchJson<DeptGroup[]>(`${BASE}/dept-stats`);
+export async function fetchDeptStats(subject?: string | null): Promise<DeptGroup[]> {
+  return fetchJson<DeptGroup[]>(withSubject(`${BASE}/dept-stats`, subject));
 }
 
-export async function fetchRegionStats(params?: { customer?: string; city?: string; region?: string }): Promise<RegionGroup[]> {
+export async function fetchRegionStats(
+  params?: { customer?: string; city?: string; region?: string },
+  subject?: string | null,
+): Promise<RegionGroup[]> {
   const query = new URLSearchParams();
   if (params?.customer) query.set('customer', params.customer);
   if (params?.city) query.set('city', params.city);
   if (params?.region) query.set('region', params.region);
+  if (subject) query.set('subject', subject);
   const qs = query.toString();
   return fetchJson<RegionGroup[]>(`${BASE}/region-stats${qs ? `?${qs}` : ''}`);
 }
 
-export async function fetchCustomerStats(): Promise<CustomerStats[]> {
-  return fetchJson<CustomerStats[]>(`${BASE}/customer-stats`);
+export async function fetchCustomerStats(subject?: string | null): Promise<CustomerStats[]> {
+  return fetchJson<CustomerStats[]>(withSubject(`${BASE}/customer-stats`, subject));
 }
 
-export async function fetchInventoryStats(): Promise<RegionalInventoryStats[]> {
-  return fetchJson<RegionalInventoryStats[]>(`${BASE}/inventory-stats`);
+export async function fetchInventoryStats(subject?: string | null): Promise<RegionalInventoryStats[]> {
+  return fetchJson<RegionalInventoryStats[]>(withSubject(`${BASE}/inventory-stats`, subject));
 }
 
-export async function fetchRegionChart(groupBy: string, top = 8, source = 'realtime'): Promise<{ name: string; value: number }[]> {
-  return fetchJson<{ name: string; value: number }[]>(`${BASE}/region-chart?groupBy=${groupBy}&top=${top}&source=${source}`);
+export async function fetchRegionChart(
+  groupBy: string,
+  top = 8,
+  source = 'realtime',
+  subject?: string | null,
+): Promise<{ name: string; value: number }[]> {
+  return fetchJson<{ name: string; value: number }[]>(
+    withSubject(`${BASE}/region-chart?groupBy=${groupBy}&top=${top}&source=${source}`, subject),
+  );
 }
 
 export async function fetchWeeklyDetail(type: string): Promise<WeeklyDetailItem[]> {