```

feat(ai_agent): 完善AI适配器和服务功能

- 添加OpenClaw和Hermes健康检查接口
- 实现OpenClaw工具调用功能
- 重构AI适配器使用常量定义
- 增加AI技能系统支持
- 更新配置文件中的默认模型提供者设置

refactor(scheduler): 使用常量替换硬编码值

- 将硬编码的actor值替换为ActorValue常量
- 将receive_id_type替换为FeishuReceiveIdType枚举

refactor(audit): 统一审计日志常量使用

- 将硬编码的actor、source、risk_level等值替换为对应常量
- 更新审核服务中的状态和操作常量引用

refactor(approvals): 标准化审批模块常量使用

- 将applicant默认值替换为ActorValue.API常量
- 使用ApprovalStatus常量替代硬编码状态值
- 更新审核操作常量引用
```

app/modules/audit/schemas.py

@@ -3,17 +3,20 @@ from typing import Any
 
 from pydantic import BaseModel, ConfigDict
 
+from app.core.constants import ActorValue
+from app.modules.audit.constants import AuditRiskLevel, AuditSource, AuditStatus
+
 
 class AuditLogCreate(BaseModel):
-    actor: str = "system"
-    source: str = "api"
+    actor: str = ActorValue.SYSTEM
+    source: str = AuditSource.API
     action: str
     target_type: str | None = None
     target_id: str | None = None
-    risk_level: str = "low"
+    risk_level: str = AuditRiskLevel.LOW
     request_payload: Any | None = None
     response_payload: Any | None = None
-    status: str = "success"
+    status: str = AuditStatus.SUCCESS
 
 
 class AuditLogRead(BaseModel):