feat(platform): expose single-source vehicles

vehicle-data-platform/apps/web/src/pages/Vehicles.tsx

@@ -50,6 +50,7 @@ export function Vehicles({
     const items: Array<{ label: string; value: string; filters: Record<string, string> }> = [
       { label: '过滤车辆', value: (summary?.totalVehicles ?? pagination.total).toLocaleString(), filters: {} },
       { label: '在线车辆', value: (summary?.onlineVehicles ?? 0).toLocaleString(), filters: { online: 'online' } },
+      { label: '单源车辆', value: (summary?.singleSourceVehicles ?? 0).toLocaleString(), filters: { coverage: 'single' } },
       { label: '多源车辆', value: (summary?.multiSourceVehicles ?? 0).toLocaleString(), filters: { coverage: 'multi' } },
       { label: '待绑定', value: (summary?.unboundVehicles ?? 0).toLocaleString(), filters: { bindingStatus: 'unbound' } }
     ];