```

feat: 添加数据库迁移脚本并更新Dockerfile配置

- 在Dockerfile中添加alembic配置文件和目录的复制指令
- 更新alembic/env.py注册新的模块模型：events、workflows、writebacks
- 生成完整的初始数据库schema迁移脚本，包含以下表：
  - approval_requests, attendance_records, audit_logs, domain_events
  - expenses, feishu_event_receipts, fund_accounts, legacy_sync_runs
  - official_writeback_runs, performance_metrics, policies, procurements
  - projects, report_push_runs, risk_event_actions, risk_events
  - standards, suppliers, work_reports, work_tasks, workflow_actions
  - workflow_instances等21个数据表结构定义
- 在API路由器中添加新模块的路由：events、workflows、writebacks、observability
```

app/modules/audit/constants.py

@@ -17,6 +17,8 @@ class AuditAction(StrEnum):
     LEGACY_SYNC_TASKS = "sync_tasks"
     RISK_EVENT_ACTION = "risk_event_action"
     REPORT_PUSH = "report_push"
+    WRITEBACK_CREATE = "writeback.create"
+    WRITEBACK_SUBMIT = "writeback.submit"
 
 
 class AuditRiskLevel(StrEnum):
@@ -33,6 +35,7 @@ class AuditSource(StrEnum):
     APPROVAL = "approval"
     LEGACY_MYSQL = "legacy_mysql"
     REPORTS = "reports"
+    WRITEBACK = "writeback"
 
 
 class AuditTargetType(StrEnum):