refactor(workflow): 统一 OSS 接口并重构恢复锁

- 将文件地址前缀与上传逻辑迁移至 common/oss
- 恢复执行改用 utils.WithLock 自动续期锁
- 转写提示词增加单镜头最小时长约束

workflow/service/flow/processor/builtin/media/media.go

@@ -8,7 +8,7 @@ import (
 	"time"
 
 	commonHttp "gitea.redpowerfuture.com/red-future/common/http"
-	"gitea.redpowerfuture.com/red-future/common/utils"
+	"gitea.redpowerfuture.com/red-future/common/oss"
 	"github.com/gogf/gf/v2/frame/g"
 	"github.com/gogf/gf/v2/util/gconv"
 )
@@ -300,7 +300,7 @@ func normalizeVideoURL(ctx context.Context, url string) string {
 	if url == "" || strings.HasPrefix(url, "http") {
 		return url
 	}
-	prefix, err := utils.GetFileAddressPrefix(ctx)
+	prefix, err := oss.GetFileAddressPrefix(ctx)
 	if err != nil {
 		g.Log().Warningf(ctx, "获取文件前缀失败，视频地址保持相对路径: %s err=%v", url, err)
 		return url