```

refactor: 移除审批和回写功能模块

移除了整个审批(approvals)和官方回写(writebacks)功能模块，
包括相关模型、路由、服务和配置项。更新了数据库迁移文件，
删除了相关的审批请求表和官方回写运行表。同时从API路由器中
移除了相应的路由，并调整了安全常量和字段验证器以匹配变更。
```

app/modules/feishu/routes.py

@@ -30,17 +30,6 @@ async def feishu_webhook(request: Request, db: Session = Depends(get_db)) -> dic
     )
 
 
-@router.post("/approval-card-action")
-async def feishu_approval_card_action(
-    request: Request,
-    db: Session = Depends(get_db),
-) -> dict:
-    """Handle Feishu interactive-card approval actions."""
-
-    payload = await request.json()
-    return FeishuEventService(db).handle_approval_card_action(payload)
-
-
 @router.post("/send-text", response_model=FeishuSendResult)
 def send_text(
     payload: FeishuTextMessage,