```

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/feishu/client.py

@@ -5,7 +5,20 @@ from typing import Any
 import httpx
 from fastapi import HTTPException
 
+from app.core.constants import BEARER_TOKEN_TEMPLATE, HttpHeader
 from app.core.config import get_settings
+from app.modules.feishu.constants import (
+    FEISHU_AUTH_MISSING,
+    FEISHU_DEFAULT_TOKEN_EXPIRE_SECONDS,
+    FEISHU_MESSAGE_PATH,
+    FEISHU_RECEIVE_ID_MISSING,
+    FEISHU_SUCCESS_CODE,
+    FEISHU_TENANT_TOKEN_PATH,
+    FEISHU_TOKEN_EXPIRE_SAFETY_SECONDS,
+    FeishuMessageType,
+    FeishuPayloadKey,
+    FeishuReceiveIdType,
+)
 
 
 class FeishuClient:
@@ -21,23 +34,26 @@ class FeishuClient:
 
     def _get_tenant_access_token(self) -> str:
         if not self._is_configured():
-            raise HTTPException(status_code=503, detail="Feishu app credentials are not configured")
+            raise HTTPException(status_code=503, detail=FEISHU_AUTH_MISSING)
         if self._tenant_access_token and time.time() < self._token_expires_at:
             return self._tenant_access_token
 
-        url = f"{self.settings.feishu_base_url}/auth/v3/tenant_access_token/internal"
+        url = f"{self.settings.feishu_base_url}{FEISHU_TENANT_TOKEN_PATH}"
         payload = {
-            "app_id": self.settings.feishu_app_id,
-            "app_secret": self.settings.feishu_app_secret,
+            FeishuPayloadKey.APP_ID: self.settings.feishu_app_id,
+            FeishuPayloadKey.APP_SECRET: self.settings.feishu_app_secret,
         }
         with httpx.Client(timeout=20) as client:
             response = client.post(url, json=payload)
             response.raise_for_status()
             data = response.json()
-        if data.get("code") != 0:
-            raise HTTPException(status_code=502, detail={"feishu_error": data})
-        self._tenant_access_token = data["tenant_access_token"]
-        self._token_expires_at = time.time() + int(data.get("expire", 7200)) - 300
+        if data.get(FeishuPayloadKey.CODE) != FEISHU_SUCCESS_CODE:
+            raise HTTPException(status_code=502, detail={FeishuPayloadKey.FEISHU_ERROR: data})
+        self._tenant_access_token = data[FeishuPayloadKey.TENANT_ACCESS_TOKEN]
+        expire_seconds = int(
+            data.get(FeishuPayloadKey.EXPIRE, FEISHU_DEFAULT_TOKEN_EXPIRE_SECONDS)
+        )
+        self._token_expires_at = time.time() + expire_seconds - FEISHU_TOKEN_EXPIRE_SAFETY_SECONDS
         return self._tenant_access_token
 
     def send_message(
@@ -48,13 +64,13 @@ class FeishuClient:
         content: dict[str, Any],
     ) -> dict[str, Any]:
         token = self._get_tenant_access_token()
-        url = f"{self.settings.feishu_base_url}/im/v1/messages"
-        headers = {"Authorization": f"Bearer {token}"}
-        params = {"receive_id_type": receive_id_type}
+        url = f"{self.settings.feishu_base_url}{FEISHU_MESSAGE_PATH}"
+        headers = {HttpHeader.AUTHORIZATION: BEARER_TOKEN_TEMPLATE.format(token=token)}
+        params = {FeishuPayloadKey.RECEIVE_ID_TYPE: receive_id_type}
         payload = {
-            "receive_id": receive_id,
-            "msg_type": msg_type,
-            "content": json.dumps(content, ensure_ascii=False),
+            FeishuPayloadKey.RECEIVE_ID: receive_id,
+            FeishuPayloadKey.MESSAGE_TYPE: msg_type,
+            FeishuPayloadKey.CONTENT: json.dumps(content, ensure_ascii=False),
         }
         with httpx.Client(timeout=20) as client:
             response = client.post(url, headers=headers, params=params, json=payload)
@@ -66,26 +82,31 @@ class FeishuClient:
         self,
         text: str,
         receive_id: str | None = None,
-        receive_id_type: str = "chat_id",
+        receive_id_type: str = FeishuReceiveIdType.CHAT_ID,
     ) -> dict:
         chat_id = receive_id or self.settings.feishu_default_chat_id
         if not chat_id:
             raise HTTPException(
                 status_code=400,
-                detail="receive_id or FEISHU_DEFAULT_CHAT_ID is required",
+                detail=FEISHU_RECEIVE_ID_MISSING,
             )
-        return self.send_message(chat_id, receive_id_type, "text", {"text": text})
+        return self.send_message(
+            chat_id,
+            receive_id_type,
+            FeishuMessageType.TEXT,
+            {FeishuPayloadKey.TEXT: text},
+        )
 
     def send_card(
         self,
         card: dict[str, Any],
         receive_id: str | None = None,
-        receive_id_type: str = "chat_id",
+        receive_id_type: str = FeishuReceiveIdType.CHAT_ID,
     ) -> dict:
         chat_id = receive_id or self.settings.feishu_default_chat_id
         if not chat_id:
             raise HTTPException(
                 status_code=400,
-                detail="receive_id or FEISHU_DEFAULT_CHAT_ID is required",
+                detail=FEISHU_RECEIVE_ID_MISSING,
             )
-        return self.send_message(chat_id, receive_id_type, "interactive", card)
+        return self.send_message(chat_id, receive_id_type, FeishuMessageType.INTERACTIVE, card)