```

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/events/constants.py

@@ -0,0 +1,62 @@
+from enum import StrEnum
+
+
+class EventStatus(StrEnum):
+    PENDING = "pending"
+    PROCESSED = "processed"
+    FAILED = "failed"
+
+
+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):
+    ITEMS = "items"
+    EVENT = "event"
+    TOTAL = "total"
+
+
+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"
+    UPDATED = "updated"
+    SKIPPED = "skipped"
+    ERROR_MESSAGE = "error_message"
+
+
+class EventErrorDetail(StrEnum):
+    EVENT_NOT_FOUND = "Domain event not found"
+
+
+EVENT_CODE_PREFIX = "EVT"