refactor(prompt): 重构异步模型字段和提示词构建服务

dao/compose_session_dao.go

@@ -75,13 +75,13 @@ func (d *composeSessionDao) Get(ctx context.Context, req *entity.ComposeSession,
 		return nil, err
 	}
 	if r.IsEmpty() {
-		return nil, nil
+		return
 	}
 	err = r.Struct(&m)
 	return
 }
 
-// Delete 软删除编排会话
+// Delete 删除编排会话
 func (d *composeSessionDao) Delete(ctx context.Context, req *entity.ComposeSession) (rows int64, err error) {
 	r, err := gfdb.DB(ctx, public.DbNameModelGateway).Model(ctx, public.TableNameComposeSession).
 		OmitEmpty().