工作流

工作流端点嵌套在具体合同下，部分操作需要 workflowAutomation 功能权益。

端点	请求体/参数	权限
`POST /contracts/:id/workflow/transition`	`note, transitionCode, toStageCode`	`contract_edit edit + workflowAutomation`
`POST /contracts/:id/workflow/lock`	`locked, note`	`admin edit + workflowAutomation`
`GET /contracts/:id/workflow/events`	—	`contract_view view`