fix(config): resolve critical audit findings from Phase 1-3 review

- C-1: Add tenant_id to settings unique index to prevent cross-tenant conflicts
- C-2: Move pg_advisory_xact_lock inside the transaction for correct concurrency
  (previously lock was released before the numbering transaction started)
- H-5: Add CORS middleware (permissive for dev, TODO: restrict in production)

crates/erp-config/src/service/numbering_service.rs

@@ -204,8 +204,8 @@ impl NumberingService {
     /// 线程安全地生成编号。
     ///
     /// 使用 PostgreSQL advisory lock 保证并发安全：
-    /// 1. 获取 pg_advisory_xact_lock
-    /// 2. 在事务内读取规则、检查重置周期、递增序列、更新数据库
+    /// 1. 在事务内获取 pg_advisory_xact_lock
+    /// 2. 在同一事务内读取规则、检查重置周期、递增序列、更新数据库
     /// 3. 拼接编号字符串返回
     pub async fn generate_number(
         rule_id: Uuid,
@@ -223,22 +223,23 @@ impl NumberingService {
         let rule_code = rule.code.clone();
         let tenant_id_str = tenant_id.to_string();
 
-        // 获取 PostgreSQL advisory lock（事务级别，事务结束自动释放）
-        db.execute(Statement::from_sql_and_values(
+        // 在同一个事务内获取 advisory lock 并执行编号生成
+        // pg_advisory_xact_lock 是事务级别的，锁会在事务结束时自动释放
+        let number = db
+            .transaction(|txn| {
+                let rule_code = rule_code.clone();
+                let tenant_id_str = tenant_id_str.clone();
+                Box::pin(async move {
+                    // 在事务内获取 advisory lock
+                    txn.execute(Statement::from_sql_and_values(
                         DatabaseBackend::Postgres,
                         "SELECT pg_advisory_xact_lock(abs(hashtext($1)), abs(hashtext($2))::int)",
-            [
-                rule_code.into(),
-                tenant_id_str.into(),
-            ],
+                        [rule_code.into(), tenant_id_str.into()],
                     ))
                     .await
                     .map_err(|e| ConfigError::Validation(format!("获取编号锁失败: {e}")))?;
 
-        // 在事务内执行序列递增和更新
-        let number = db
-            .transaction(|txn| {
-                Box::pin(async move {
+                    // 在同一个事务内执行编号生成
                     Self::generate_number_in_txn(rule_id, tenant_id, txn).await
                 })
             })

crates/erp-server/migration/src/m20260412_000016_create_settings.rs

@@ -68,7 +68,7 @@ impl MigrationTrait for Migration {
 
         manager.get_connection().execute(sea_orm::Statement::from_string(
             sea_orm::DatabaseBackend::Postgres,
-            "CREATE UNIQUE INDEX idx_settings_scope_key ON settings (scope, scope_id, setting_key) WHERE deleted_at IS NULL".to_string(),
+            "CREATE UNIQUE INDEX idx_settings_scope_key ON settings (tenant_id, scope, scope_id, setting_key) WHERE deleted_at IS NULL".to_string(),
         )).await.map_err(|e| DbErr::Custom(e.to_string()))?;
 
         Ok(())

crates/erp-server/src/main.rs

@@ -153,7 +153,11 @@ async fn main() -> anyhow::Result<()> {
         .with_state(state.clone());
 
     // Merge public + protected into the final application router
-    let app = Router::new().merge(public_routes).merge(protected_routes);
+    let cors = tower_http::cors::CorsLayer::permissive(); // TODO: restrict origins in production
+    let app = Router::new()
+        .merge(public_routes)
+        .merge(protected_routes)
+        .layer(cors);
 
     let addr = format!("{}:{}", host, port);
     let listener = tokio::net::TcpListener::bind(&addr).await?;