```

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/schemas.py

@@ -0,0 +1,21 @@
+from typing import Any
+
+from pydantic import BaseModel
+
+
+class WorkflowRead(BaseModel):
+    code: str
+    workflow_type: str
+    aggregate_type: str
+    aggregate_id: str | None
+    status: str
+    actor: str
+    current_step: str | None
+    payload: dict[str, Any] | None
+    created_at: str
+    updated_at: str
+    completed_at: str | None
+
+
+class WorkflowListRead(BaseModel):
+    items: list[dict[str, Any]]