feat(core): implement event outbox persistence

Add domain_events migration and SeaORM entity. Modify EventBus::publish
to persist events before broadcasting (best-effort: DB failure logs
warning but still broadcasts in-memory). Update all 19 publish call
sites across 4 crates to pass db reference.

Add outbox relay background task that polls pending events every 5s
and re-broadcasts them, ensuring no events are lost on server restart.

crates/erp-server/Cargo.toml

@@ -29,3 +29,4 @@ erp-workflow.workspace = true
 erp-message.workspace = true
 anyhow.workspace = true
 uuid.workspace = true
+chrono.workspace = true

crates/erp-server/migration/src/lib.rs

@@ -30,6 +30,7 @@ mod m20260414_000027_fix_unique_indexes_soft_delete;
 mod m20260414_000028_add_standard_fields_to_tokens;
 mod m20260414_000029_add_standard_fields_to_process_variables;
 mod m20260415_000030_add_version_to_message_tables;
+mod m20260416_000031_create_domain_events;
 
 pub struct Migrator;
 
@@ -67,6 +68,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20260414_000028_add_standard_fields_to_tokens::Migration),
             Box::new(m20260414_000029_add_standard_fields_to_process_variables::Migration),
             Box::new(m20260415_000030_add_version_to_message_tables::Migration),
+            Box::new(m20260416_000031_create_domain_events::Migration),
         ]
     }
 }

crates/erp-server/migration/src/m20260416_000031_create_domain_events.rs

@@ -0,0 +1,80 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_table(
+                Table::create()
+                    .table(Alias::new("domain_events"))
+                    .if_not_exists()
+                    .col(
+                        ColumnDef::new(Alias::new("id"))
+                            .uuid()
+                            .not_null()
+                            .primary_key(),
+                    )
+                    .col(ColumnDef::new(Alias::new("tenant_id")).uuid().not_null())
+                    .col(ColumnDef::new(Alias::new("event_type")).string_len(200).not_null())
+                    .col(ColumnDef::new(Alias::new("payload")).json().null())
+                    .col(ColumnDef::new(Alias::new("correlation_id")).uuid().null())
+                    .col(
+                        ColumnDef::new(Alias::new("status"))
+                            .string_len(20)
+                            .not_null()
+                            .default("pending"),
+                    )
+                    .col(
+                        ColumnDef::new(Alias::new("attempts"))
+                            .integer()
+                            .not_null()
+                            .default(0),
+                    )
+                    .col(ColumnDef::new(Alias::new("last_error")).text().null())
+                    .col(
+                        ColumnDef::new(Alias::new("created_at"))
+                            .timestamp_with_time_zone()
+                            .not_null(),
+                    )
+                    .col(
+                        ColumnDef::new(Alias::new("published_at"))
+                            .timestamp_with_time_zone()
+                            .null(),
+                    )
+                    .to_owned(),
+            )
+            .await?;
+
+        manager
+            .create_index(
+                Index::create()
+                    .name("idx_domain_events_status")
+                    .table(Alias::new("domain_events"))
+                    .col(Alias::new("status"))
+                    .col(Alias::new("created_at"))
+                    .to_owned(),
+            )
+            .await?;
+
+        manager
+            .create_index(
+                Index::create()
+                    .name("idx_domain_events_tenant")
+                    .table(Alias::new("domain_events"))
+                    .col(Alias::new("tenant_id"))
+                    .to_owned(),
+            )
+            .await?;
+
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .drop_table(Table::drop().table(Alias::new("domain_events")).to_owned())
+            .await
+    }
+}

crates/erp-server/src/main.rs

@@ -2,6 +2,7 @@ mod config;
 mod db;
 mod handlers;
 mod middleware;
+mod outbox;
 mod state;
 
 /// OpenAPI 规范定义（预留，未来可通过 utoipa derive 合并各模块 schema）。
@@ -142,6 +143,10 @@ async fn main() -> anyhow::Result<()> {
     erp_message::MessageModule::start_event_listener(db.clone(), event_bus.clone());
     tracing::info!("Message event listener started");
 
+    // Start outbox relay (re-publish pending domain events)
+    outbox::start_outbox_relay(db.clone(), event_bus.clone());
+    tracing::info!("Outbox relay started");
+
     let host = config.server.host.clone();
     let port = config.server.port;
 

crates/erp-server/src/outbox.rs

@@ -0,0 +1,58 @@
+use chrono::Utc;
+use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter, Set};
+use std::time::Duration;
+
+use erp_core::entity::domain_event;
+use erp_core::events::{DomainEvent, EventBus};
+
+/// 启动 outbox relay 后台任务。
+///
+/// 定期扫描 domain_events 表中 status = 'pending' 的事件，
+/// 重新广播并标记为 published。
+pub fn start_outbox_relay(db: sea_orm::DatabaseConnection, event_bus: EventBus) {
+    tokio::spawn(async move {
+        let mut interval = tokio::time::interval(Duration::from_secs(5));
+        loop {
+            interval.tick().await;
+            if let Err(e) = process_pending_events(&db, &event_bus).await {
+                tracing::warn!(error = %e, "Outbox relay 处理失败");
+            }
+        }
+    });
+}
+
+async fn process_pending_events(
+    db: &sea_orm::DatabaseConnection,
+    event_bus: &EventBus,
+) -> Result<(), sea_orm::DbErr> {
+    let pending = domain_event::Entity::find()
+        .filter(domain_event::Column::Status.eq("pending"))
+        .filter(domain_event::Column::Attempts.lt(3))
+        .all(db)
+        .await?;
+
+    if pending.is_empty() {
+        return Ok(());
+    }
+
+    tracing::info!(count = pending.len(), "处理待发领域事件");
+
+    for event_model in pending {
+        // 重建 DomainEvent 并广播
+        let domain_event = DomainEvent::new(
+            &event_model.event_type,
+            event_model.tenant_id,
+            event_model.payload.clone().unwrap_or(serde_json::json!({})),
+        );
+
+        event_bus.broadcast(domain_event);
+
+        // 标记为 published
+        let mut active: domain_event::ActiveModel = event_model.into();
+        active.status = Set("published".to_string());
+        active.published_at = Set(Some(Utc::now()));
+        active.update(db).await?;
+    }
+
+    Ok(())
+}