```

feat: 添加飞书用户模块和订阅功能支持

- 新增feishu_users模块用于处理飞书用户身份验证和权限管理
- 新增subscriptions模块用于处理订阅相关功能
- 新增personalization模块用于个性化服务
- 在alembic迁移配置中注册新的模型模块
- 在API路由器中添加feishu_users和subscriptions路由
- 实现事件调度服务的改进，包括错误处理和状态更新优化
- 添加飞书命令处理的权限检查机制
- 实现飞书应用票据事件处理
- 改进审计日志记录功能
```

app/modules/subscriptions/constants.py

@@ -0,0 +1,65 @@
+from enum import StrEnum
+
+
+class SubscriptionTargetType(StrEnum):
+    USER = "user"
+    CHAT = "chat"
+
+
+class SubscriptionScheduleType(StrEnum):
+    ONCE = "once"
+    DAILY = "daily"
+    WEEKDAY = "weekday"
+    WEEKLY = "weekly"
+    MONTHLY = "monthly"
+    INTERVAL = "interval"
+
+
+class PushSubscriptionStatus(StrEnum):
+    ACTIVE = "active"
+    PAUSED = "paused"
+    CANCELLED = "cancelled"
+    COMPLETED = "completed"
+
+
+class PushDeliveryStatus(StrEnum):
+    PENDING = "pending"
+    PROCESSING = "processing"
+    RETRY = "retry"
+    SENT = "sent"
+    FAILED = "failed"
+    SKIPPED = "skipped"
+
+
+class SubscriptionAuditAction(StrEnum):
+    CREATE = "subscription.create"
+    PAUSE = "subscription.pause"
+    RESUME = "subscription.resume"
+    CANCEL = "subscription.cancel"
+    UPDATE_TIMEZONE = "subscription.update_timezone"
+    UPDATE_QUIET_HOURS = "subscription.update_quiet_hours"
+    DELIVERY_SENT = "subscription.delivery.sent"
+    DELIVERY_FAILED = "subscription.delivery.failed"
+    DELIVERY_SKIPPED = "subscription.delivery.skipped"
+
+
+DEFAULT_SUBSCRIPTION_TIMEZONE = "Asia/Shanghai"
+MAX_ACTIVE_SUBSCRIPTIONS = 50
+MAX_DAILY_DELIVERIES = 96
+MIN_INTERVAL_MINUTES = 15
+DELIVERY_RETRY_DELAYS_SECONDS = (60, 300, 900)
+SUBSCRIPTION_LEASE_SECONDS = 120
+DELIVERY_LEASE_SECONDS = 300
+
+SUBSCRIPTION_NOT_FOUND = "Subscription not found"
+DELIVERY_NOT_FOUND = "Subscription delivery not found"
+SUBSCRIPTION_LIMIT_REACHED = "A user may enable at most 50 subscriptions"
+DAILY_DELIVERY_LIMIT_REACHED = "Daily delivery limit reached"
+INVALID_SCHEDULE = "Unsupported or invalid schedule expression"
+INVALID_TIMEZONE = "Invalid IANA timezone"
+INVALID_QUIET_HOURS = "Quiet hours must use different HH:MM start and end values"
+INVALID_PRIVATE_TARGET = "Private subscriptions must target the current user's open_id"
+INVALID_GROUP_TARGET = "Group subscriptions must be created by an administrator in the current group"
+INACTIVE_USER = "Feishu user is disabled"
+EMPTY_PROMPT = "Subscription prompt is required"
+