perf: 优化订阅刷新逻辑

packages/server/prisma/migrations/20260907070000_add_user_last_login_at/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE `users` ADD COLUMN `last_login_at` DATETIME(3) NULL;

packages/server/prisma/schema.prisma

@@ -80,6 +80,7 @@ model User {
   avatarUrl                        String?  @map("avatar_url")
   role                             UserRole @default(MEMBER)
   adminBookingSubscriptionCount    Int      @default(0) @map("admin_booking_subscription_count")
+  lastLoginAt                      DateTime? @map("last_login_at")
   createdAt                        DateTime @default(now()) @map("created_at")
   updatedAt                        DateTime @updatedAt @map("updated_at")