```

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/core/constants.py

@@ -15,6 +15,7 @@ class HttpHeader(StrEnum):
     X_API_KEY = "X-API-Key"
     X_AUDIT_API_KEY = "X-Audit-API-Key"
     X_APPROVAL_API_KEY = "X-Approval-API-Key"
+    X_REQUEST_ID = "X-Request-ID"
 
 
 class ApiResponseKey(StrEnum):