```

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/constants.py

@@ -8,30 +8,23 @@ class EventStatus(StrEnum):
 
 
 class EventType(StrEnum):
-    APPROVAL_DECIDED = "approval.decided"
     RISK_ACTION_RECORDED = "risk.action_recorded"
     REPORT_PUSH_SUCCEEDED = "report.push_succeeded"
     REPORT_PUSH_FAILED = "report.push_failed"
     LEGACY_SYNC_COMPLETED = "legacy.sync_completed"
-    WRITEBACK_REQUESTED = "writeback.requested"
-    WRITEBACK_SUBMITTED = "writeback.submitted"
 
 
 class EventSource(StrEnum):
-    APPROVAL = "approval"
     RISK = "risk"
     REPORTS = "reports"
     LEGACY_MYSQL = "legacy_mysql"
-    WRITEBACK = "writeback"
     API = "api"
 
 
 class EventAggregateType(StrEnum):
-    APPROVAL = "approval"
     RISK_EVENT = "risk-event"
     REPORT_PUSH_RUN = "report-push-run"
     LEGACY_SYNC_RUN = "legacy-sync-run"
-    WRITEBACK_RUN = "writeback-run"
 
 
 class EventResponseKey(StrEnum):
@@ -43,10 +36,8 @@ class EventResponseKey(StrEnum):
 class EventPayloadKey(StrEnum):
     ACTION = "action"
     STATUS = "status"
-    TICKET_ID = "ticket_id"
     DOMAIN = "domain"
     RECORD_ID = "record_id"
-    APPROVED = "approved"
     COMMENT = "comment"
     CODE = "code"
     CREATED = "created"