perf(diary): parent_service 批量软删除替代逐条 UPDATE — 8a-C03

- delete_child_data 改用单条 SQL UPDATE ... WHERE 批量软删除
- 1 次 SQL 替代 N 次逐条 UPDATE（从 O(N) 降到 O(1) 查询）
- 移除不再需要的 TransactionTrait 导入
- 测试 80/80 通过

crates/erp-diary/src/service/parent_service.rs

@@ -2,8 +2,8 @@
 
 use chrono::Utc;
 use sea_orm::{
-    ActiveModelTrait, ColumnTrait, DatabaseConnection, EntityTrait, PaginatorTrait,
-    QueryFilter, QueryOrder, Set, TransactionTrait,
+    ActiveModelTrait, ColumnTrait, ConnectionTrait, DatabaseConnection, EntityTrait,
+    PaginatorTrait, QueryFilter, QueryOrder, Set,
 };
 use uuid::Uuid;
 
@@ -272,7 +272,8 @@ impl ParentService {
 
     /// 删除孩子数据 — 软删除所有日记（PIPL 删除权）
     ///
-    /// 软删除孩子全部未删除的日记，逐条设置 deleted_at。
+    /// 使用单条 SQL UPDATE 批量软删除，替代逐条更新。
+    /// 性能: 1 次 SQL 替代 N 次 UPDATE。
     /// 发布 `diary.parent.data_deleted` 事件记录操作。
     pub async fn delete_child_data(
         tenant_id: Uuid,
@@ -283,32 +284,33 @@ impl ParentService {
     ) -> DiaryResult<usize> {
         Self::verify_binding(tenant_id, parent_id, child_id, db).await?;
 
-        let journals = journal_entry::Entity::find()
-            .filter(journal_entry::Column::TenantId.eq(tenant_id))
-            .filter(journal_entry::Column::AuthorId.eq(child_id))
-            .filter(journal_entry::Column::DeletedAt.is_null())
-            .all(db)
-            .await?;
-
-        let count = journals.len();
         let now = Utc::now();
 
-        // 事务：软删除所有日记（PIPL 删除权 — 原子操作，避免部分删除）
-        db.transaction::<_, (), DiaryError>(|txn| {
-            Box::pin(async move {
-                for journal in journals {
-                    let current_version = journal.version;
-                    let mut active: journal_entry::ActiveModel = journal.into();
-                    active.deleted_at = Set(Some(now));
-                    active.updated_at = Set(now);
-                    active.updated_by = Set(parent_id);
-                    active.version = Set(current_version + 1);
-                    active.update(txn).await?;
-                }
-                Ok(())
-            })
-        })
-        .await?;
+        // 批量软删除 — 单条 SQL 替代逐条 UPDATE（性能优化 8a-C03）
+        let sql = r#"
+            UPDATE journal_entries
+            SET deleted_at = $1,
+                updated_at = $1,
+                updated_by = $2,
+                version = version + 1
+            WHERE tenant_id = $3
+              AND author_id = $4
+              AND deleted_at IS NULL
+        "#;
+
+        let stmt = sea_orm::Statement::from_sql_and_values(
+            sea_orm::DatabaseBackend::Postgres,
+            sql,
+            [
+                now.into(),
+                parent_id.into(),
+                tenant_id.into(),
+                child_id.into(),
+            ],
+        );
+
+        let result = db.execute(stmt).await?;
+        let count = result.rows_affected() as usize;
 
         event_bus
             .publish(