feat(core): 事件归档 + 消费者幂等性 — 迁移 084/085 + 清理任务

- 迁移 084: domain_events_archive 归档表 + cleanup_old_published_events()
- 迁移 085: processed_events 去重表 + cleanup_old_processed_events()
- erp-core: is_event_processed() / mark_event_processed() 幂等性辅助
- erp-server: tasks::start_event_cleanup() 每 24h 归档 >90 天事件

crates/erp-core/src/entity/mod.rs

@@ -1,2 +1,3 @@
 pub mod audit_log;
 pub mod domain_event;
+pub mod processed_event;

crates/erp-core/src/entity/processed_event.rs

@@ -0,0 +1,18 @@
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+/// 已处理事件记录 — 幂等性去重表。
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "processed_events")]
+pub struct Model {
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub event_id: Uuid,
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub consumer_id: String,
+    pub processed_at: DateTimeUtc,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}