feat(workflow): 增加工作流计费与执行生命周期管理

- 新增计费模块：执行开始建单、终态结算/取消/失败处理，支持按条/按秒/按token计费
- 新增执行生命周期跟踪：优雅关停时取消运行中执行并等待落库
- 新增异步任务等待/通知机制（Wait/Notify）
- 重构执行记录落库与进度上报，统一失败分类与重试语义
- 重命名文件：async_task.go→async.go、flow_checkpoint_store.go→exec_checkpoint.go、flow_graph_util.go→exec_record.go
- 更新 .gitignore 与数据库密码配置

workflow/service/flow/lambda_script_transcribe.go

@@ -4,6 +4,7 @@ import (
 	"ai-agent/workflow/consts/node"
 	"ai-agent/workflow/service/flow/processor"
 	"ai-agent/workflow/service/flow/processor/builtin/split_shots_pipeline"
+	"ai-agent/workflow/service/flow/values"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -81,7 +82,7 @@ func ScriptTranscribeLambda(ctx context.Context, input any) (any, error) {
 		}
 	}
 
-	modelParams, err := BuildModelRequestBody(nodeInput.Config.ModelConfig.ModelRequestParamsPath, nodeInput.Global)
+	modelParams, err := values.BuildModelRequestBody(nodeInput.Config.ModelConfig.ModelRequestParamsPath, nodeInput.Global)
 	if err != nil {
 		return nil, err
 	}