🐛 fix(query-editor): 修正 SQL 编辑器 DML 事务识别

- 统一前后端 DML 与数据修改 CTE 的受管事务判断

- 保留数据修改 CTE 返回行并补充事务回归测试

- 明确 SQL 编辑器事务提交策略文案

internal/app/sql_sanitize_test.go

@@ -79,6 +79,11 @@ func TestIsReadOnlySQLQuery_ClassifiesWithByTopLevelOperation(t *testing.T) {
 	if isReadOnlySQLQuery("postgres", writeQuery) {
 		t.Fatal("WITH ... UPDATE should not be treated as read-only")
 	}
+
+	writeCTEQuery := "WITH moved AS (DELETE FROM audit_logs WHERE created_at < NOW() RETURNING id) SELECT * FROM moved"
+	if isReadOnlySQLQuery("postgres", writeCTEQuery) {
+		t.Fatal("data-changing CTE should not be treated as read-only")
+	}
 }
 
 func TestIsBatchableWriteSQLStatement_OnlyMatchesRealWriteStatements(t *testing.T) {
@@ -88,6 +93,9 @@ func TestIsBatchableWriteSQLStatement_OnlyMatchesRealWriteStatements(t *testing.
 	if !isBatchableWriteSQLStatement("postgres", "WITH target AS (SELECT id FROM users) DELETE FROM users WHERE id IN (SELECT id FROM target)") {
 		t.Fatal("expected WITH ... DELETE to be treated as batchable write")
 	}
+	if !isBatchableWriteSQLStatement("postgres", "WITH moved AS (DELETE FROM audit_logs WHERE created_at < NOW() RETURNING id) SELECT * FROM moved") {
+		t.Fatal("expected data-changing CTE to be treated as batchable write")
+	}
 	if isBatchableWriteSQLStatement("sqlserver", "EXEC sp_who2") {
 		t.Fatal("EXEC should not be treated as batchable write")
 	}
@@ -116,3 +124,10 @@ func TestShouldTryQueryResultFirst_TreatsSQLServerSystemCommandsAsQueryFirst(t *
 		t.Fatal("non-SQLServer system procedure name should not force query-first")
 	}
 }
+
+func TestShouldTryQueryResultFirst_TreatsDataChangingCTESelectAsQueryFirst(t *testing.T) {
+	query := "WITH moved AS (DELETE FROM audit_logs WHERE created_at < NOW() RETURNING id) SELECT * FROM moved"
+	if !shouldTryQueryResultFirst("postgres", query) {
+		t.Fatal("data-changing CTE ending in SELECT should try query-first to preserve returned rows")
+	}
+}