refactor(task): extract billing and polling logic from controller to service layer

Restructure the task relay system for better separation of concerns:
- Extract task billing into service/task_billing.go with unified settlement flow
- Move task polling loop from controller to service/task_polling.go (supports Suno + video platforms)
- Split RelayTask into fetch/submit paths with dedicated retry logic (taskSubmitWithRetry)
- Add TaskDto, TaskResponse generics, and FetchReq to dto/task.go
- Add taskcommon/helpers.go for shared task adaptor utilities
- Remove controller/task_video.go (logic consolidated into service layer)
- Update all task adaptors (ali, doubao, gemini, hailuo, jimeng, kling, sora, suno, vertex, vidu)
- Simplify frontend task logs to use new TaskDto response format

relay/channel/task/ali/adaptor.go

@@ -384,7 +384,8 @@ func (a *TaskAdaptor) DoResponse(c *gin.Context, resp *http.Response, info *rela
 
 	// 转换为 OpenAI 格式响应
 	openAIResp := dto.NewOpenAIVideo()
-	openAIResp.ID = aliResp.Output.TaskID
+	openAIResp.ID = info.PublicTaskID
+	openAIResp.TaskID = info.PublicTaskID
 	openAIResp.Model = c.GetString("model")
 	if openAIResp.Model == "" && info != nil {
 		openAIResp.Model = info.OriginModelName