```

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/workflows/constants.py

@@ -0,0 +1,29 @@
+from enum import StrEnum
+
+
+class WorkflowType(StrEnum):
+    RISK_EVENT_REVIEW = "risk_event_review"
+    OFFICIAL_WRITEBACK = "official_writeback"
+
+
+class WorkflowStatus(StrEnum):
+    WAITING_APPROVAL = "waiting_approval"
+    WAITING_REVIEW = "waiting_review"
+    RUNNING = "running"
+    BLOCKED = "blocked"
+    COMPLETED = "completed"
+    FAILED = "failed"
+
+
+class WorkflowResponseKey(StrEnum):
+    ITEMS = "items"
+    WORKFLOW = "workflow"
+    ACTION = "action"
+
+
+class WorkflowErrorDetail(StrEnum):
+    WORKFLOW_NOT_FOUND = "Workflow instance not found"
+
+
+WORKFLOW_CODE_PREFIX = "WF"
+WORKFLOW_ACTION_CODE_PREFIX = "WF-ACTION"