feat: 优化微信订阅消息体系并新增约课取消通知与开课前1小时提醒

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/server/prisma/schema.prisma

@@ -220,6 +220,9 @@ model Booking {
   reviewReminderDueAt DateTime? @map("review_reminder_due_at")
   reviewReminderClaimedAt DateTime? @map("review_reminder_claimed_at")
   reviewReminderSentAt DateTime? @map("review_reminder_sent_at")
+  classReminderDueAt DateTime? @map("class_reminder_due_at")
+  classReminderClaimedAt DateTime? @map("class_reminder_claimed_at")
+  classReminderSentAt DateTime? @map("class_reminder_sent_at")
   statusHistory BookingStatusHistory[]
 
   @@unique([userId, timeSlotId])