feat(subscription): 订阅过期状态自动更新与服务端排序

- 新增 SubscriptionExpiryService 定时任务，每分钟更新过期订阅状态
- 订阅列表支持服务端排序（按过期时间、状态、创建时间）
- 实时显示正确的过期状态，无需等待定时任务
- 允许对已过期订阅进行续期操作
- DataTable 组件支持 serverSideSort 模式

backend/internal/service/wire.go

@@ -72,6 +72,13 @@ func ProvideAccountExpiryService(accountRepo AccountRepository) *AccountExpirySe
 	return svc
 }
 
+// ProvideSubscriptionExpiryService creates and starts SubscriptionExpiryService.
+func ProvideSubscriptionExpiryService(userSubRepo UserSubscriptionRepository) *SubscriptionExpiryService {
+	svc := NewSubscriptionExpiryService(userSubRepo, time.Minute)
+	svc.Start()
+	return svc
+}
+
 // ProvideTimingWheelService creates and starts TimingWheelService
 func ProvideTimingWheelService() (*TimingWheelService, error) {
 	svc, err := NewTimingWheelService()
@@ -256,6 +263,7 @@ var ProviderSet = wire.NewSet(
 	ProvideUpdateService,
 	ProvideTokenRefreshService,
 	ProvideAccountExpiryService,
+	ProvideSubscriptionExpiryService,
 	ProvideTimingWheelService,
 	ProvideDashboardAggregationService,
 	ProvideUsageCleanupService,