```

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/risk/service.py

@@ -2,7 +2,6 @@ from datetime import date
 from decimal import Decimal
 from typing import Any
 
-from fastapi import HTTPException, status
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
@@ -17,15 +16,12 @@ from app.modules.audit.constants import (
 )
 from app.modules.audit.schemas import AuditLogCreate
 from app.modules.audit.service import AuditService
-from app.modules.approvals.constants import ApprovalActionValue, approval_action
-from app.modules.approvals.service import ApprovalService
 from app.modules.business.constants import (
     CLOSED_RISK_STATUSES,
     DONE_STATUSES,
     GENERATED_RISK_EVENT_TYPES,
     PROJECT_CLOSED_STATUSES,
     SUPPLIER_RISK_LEVELS,
-    BusinessErrorDetail,
     BusinessDomain,
     RiskEventType,
     RiskLevel,
@@ -203,20 +199,8 @@ class RiskService:
         closed_reason: str,
         review_summary: str | None = None,
         actor: str = ActorValue.API,
-        approval_ticket_id: str | None = None,
     ) -> dict[str, Any]:
         record = self._get_event(risk_event_id)
-        approval_payload = {
-            RiskEventPayloadKey.STATUS: StatusValue.CLOSED,
-            "closed_reason": closed_reason,
-            RiskEventActionKey.REVIEW_SUMMARY: review_summary,
-        }
-        self._consume_risk_approval(
-            approval_ticket_id,
-            risk_event_id,
-            approval_payload,
-            actor,
-        )
         from_status = record.status
         now = utc_now()
         record.status = StatusValue.CLOSED
@@ -244,19 +228,8 @@ class RiskService:
         risk_event_id: int,
         comment: str | None = None,
         actor: str = ActorValue.API,
-        approval_ticket_id: str | None = None,
     ) -> dict[str, Any]:
         record = self._get_event(risk_event_id)
-        approval_payload = {
-            RiskEventPayloadKey.STATUS: StatusValue.OPEN,
-            RiskEventActionKey.COMMENT: comment,
-        }
-        self._consume_risk_approval(
-            approval_ticket_id,
-            risk_event_id,
-            approval_payload,
-            actor,
-        )
         from_status = record.status
         record.status = StatusValue.OPEN
         record.resolved_at = None
@@ -384,27 +357,6 @@ class RiskService:
             RiskEventActionKey.ACTION_RECORD: serialize_model(action),
         }
 
-    def _consume_risk_approval(
-        self,
-        approval_ticket_id: str | None,
-        risk_event_id: int,
-        payload: dict[str, Any],
-        actor: str,
-    ) -> None:
-        if not approval_ticket_id:
-            raise HTTPException(
-                status_code=status.HTTP_409_CONFLICT,
-                detail=BusinessErrorDetail.HIGH_RISK_APPROVAL_REQUIRED,
-            )
-        ApprovalService(self.db).consume_for(
-            approval_ticket_id,
-            BusinessDomain.RISK_EVENTS,
-            risk_event_id,
-            approval_action(ApprovalActionValue.UPDATE, BusinessDomain.RISK_EVENTS),
-            payload,
-            actor,
-        )
-
     def generate_events(self, actor: str = ActorValue.API) -> dict[str, Any]:
         """Generate or refresh risk-event ledger entries from current signals."""