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/server/routes/vehicles.ts

@@ -313,11 +313,21 @@ async function getVehicles(): Promise<Vehicle[]> {
 async function getVehiclesForUser(c: Context): Promise<Vehicle[]> {
   const all = await getVehicles();
   const user = ((c as any).get?.('user') || (c as any).var?.user) as AuthUser | undefined;
-  if (user) {
-    const filtered = filterByPermission(all, user);
-    return maskCustomerNames(filtered);
-  }
-  return maskCustomerNames(all);
+  let list = user ? filterByPermission(all, user) : all;
+  list = applySubjectFilter(c, list);
+  return maskCustomerNames(list);
+}
+
+// 归属公司筛选（所属公司 = tab_truck.org_id → org_name, 即 Vehicle.subjectOrg）
+function getSubjectParam(c: Context): string | null {
+  const raw = (c.req.query('subject') || '').trim();
+  return raw ? raw : null;
+}
+
+function applySubjectFilter(c: Context, vehicles: Vehicle[]): Vehicle[] {
+  const subject = getSubjectParam(c);
+  if (!subject) return vehicles;
+  return vehicles.filter((v) => (v.subjectOrg || '') === subject);
 }
 
 function getRegionCounts(vehicles: Vehicle[], regions: readonly string[]): Record<string, number> {
@@ -611,7 +621,7 @@ app.get('/by-batch', async (c) => {
 
 // GET /api/vehicles/inventory-analysis — 库存分析，不设数据权限，对所有人开放
 app.get('/inventory-analysis', async (c) => {
-  const vehicles = await getVehicles();
+  const vehicles = applySubjectFilter(c, await getVehicles());
 
   const typeFilters = [
     { name: '4.5T普货', filter: (v: Vehicle) => v.type === '4.5T' && !v.model.includes('冷链') },
@@ -978,7 +988,7 @@ app.get('/list', async (c) => {
 
 // GET /api/vehicles/inventory-stats — 库存统计，不设数据权限，对所有人开放
 app.get('/inventory-stats', async (c) => {
-  const vehicles = await getVehicles();
+  const vehicles = applySubjectFilter(c, await getVehicles());
   const inventory = vehicles.filter((v) => v.status === 'Inventory' || v.status === 'Abnormal');
 
   const TYPE_NAME_MAP: Record<string, string> = {
@@ -1037,6 +1047,30 @@ app.get('/weekly-detail', async (c) => {
   return c.json(masked);
 });
 
+// GET /api/vehicles/subjects — 归属公司列表（含台数预览），用于顶部筛选下拉
+app.get('/subjects', async (c) => {
+  const all = await getVehicles();
+  const user = ((c as any).get?.('user') || (c as any).var?.user) as AuthUser | undefined;
+  const visible = user ? filterByPermission(all, user) : all;
+
+  const map = new Map<string, { total: number; inventory: number; operating: number }>();
+  for (const v of visible) {
+    const name = (v.subjectOrg || '').trim();
+    if (!name) continue;
+    if (!map.has(name)) map.set(name, { total: 0, inventory: 0, operating: 0 });
+    const s = map.get(name)!;
+    s.total += 1;
+    if (v.status === 'Inventory' || v.status === 'Abnormal') s.inventory += 1;
+    if (v.status === 'Operating') s.operating += 1;
+  }
+
+  const result = Array.from(map.entries())
+    .map(([name, stats]) => ({ name, ...stats }))
+    .sort((a, b) => b.total - a.total);
+
+  return c.json(result);
+});
+
 // GET /api/vehicles/refresh — force cache refresh
 app.get('/refresh', async (c) => {
   lastFetchTime = 0;