```

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/events/service.py

@@ -131,9 +131,6 @@ class EventService:
     def _handle_event(self, record: DomainEvent) -> None:
         if record.event_type == EventType.RISK_ACTION_RECORDED:
             self._handle_risk_action(record)
-            return
-        if record.event_type in {EventType.WRITEBACK_REQUESTED, EventType.WRITEBACK_SUBMITTED}:
-            self._handle_writeback(record)
 
     def _handle_risk_action(self, record: DomainEvent) -> None:
         from app.modules.risk.constants import RiskEventActionValue
@@ -157,28 +154,3 @@ class EventService:
             actor=record.actor,
             payload=payload,
         )
-
-    def _handle_writeback(self, record: DomainEvent) -> None:
-        from app.modules.workflows.service import WorkflowService
-        from app.modules.workflows.constants import WorkflowStatus, WorkflowType
-        from app.modules.writebacks.constants import WritebackStatus
-
-        payload = record.payload or {}
-        run_status = str(payload.get(EventPayloadKey.STATUS) or "")
-        if run_status == WritebackStatus.SENT:
-            workflow_status = WorkflowStatus.COMPLETED
-        elif run_status == WritebackStatus.FAILED:
-            workflow_status = WorkflowStatus.FAILED
-        elif run_status == WritebackStatus.DISABLED:
-            workflow_status = WorkflowStatus.BLOCKED
-        else:
-            workflow_status = WorkflowStatus.WAITING_APPROVAL
-        WorkflowService(self.db).start_or_update(
-            workflow_type=WorkflowType.OFFICIAL_WRITEBACK,
-            aggregate_type=EventAggregateType.WRITEBACK_RUN,
-            aggregate_id=record.aggregate_id,
-            status_value=workflow_status,
-            action=record.event_type,
-            actor=record.actor,
-            payload=payload,
-        )