Show aftersales stats and recent orders on dashboard

- Adds a second row of cards (total / pending / closed / rejected)
- New "最近售后工单" table linking to detail pages
- DashboardStats type extended; dashboardApi maps backend overview

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/types/index.ts

@@ -99,12 +99,26 @@ export interface ApiResponse<T> {
   error?: string;
 }
 
+export interface DashboardRecentAftersales {
+  serialNumber: string;
+  companyName: string;
+  serviceType: AftersalesServiceType;
+  workOrderStatus: AftersalesWorkOrderStatus;
+  authorizationStatus: AftersalesAuthorizationStatus;
+  technicianName: string;
+  createdAt: string;
+}
+
 export interface DashboardStats {
   totalCompanies: number;
   totalSerials: number;
   totalEmployeeSerials: number;
   activeSerials: number;
   inactiveSerials: number;
+  totalAftersales: number;
+  pendingConfirmation: number;
+  closedAftersales: number;
+  rejectedAftersales: number;
   monthlyData: Array<{
     month: string;
     companies: number;
@@ -112,6 +126,7 @@ export interface DashboardStats {
   }>;
   recentCompanies: Company[];
   recentSerials: Serial[];
+  recentAftersales: DashboardRecentAftersales[];
 }
 
 export interface CompanyFilter {