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/vidu/adaptor.go

@@ -2,7 +2,6 @@ package vidu
 
 import (
 	"bytes"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -16,6 +15,7 @@ import (
 	"github.com/QuantumNous/new-api/dto"
 	"github.com/QuantumNous/new-api/model"
 	"github.com/QuantumNous/new-api/relay/channel"
+	taskcommon "github.com/QuantumNous/new-api/relay/channel/task/taskcommon"
 	relaycommon "github.com/QuantumNous/new-api/relay/common"
 	"github.com/QuantumNous/new-api/service"
 
@@ -127,7 +127,7 @@ func (a *TaskAdaptor) BuildRequestBody(c *gin.Context, info *relaycommon.RelayIn
 		}
 	}
 
-	data, err := json.Marshal(body)
+	data, err := common.Marshal(body)
 	if err != nil {
 		return nil, err
 	}
@@ -168,7 +168,7 @@ func (a *TaskAdaptor) DoResponse(c *gin.Context, resp *http.Response, info *rela
 	}
 
 	var vResp responsePayload
-	err = json.Unmarshal(responseBody, &vResp)
+	err = common.Unmarshal(responseBody, &vResp)
 	if err != nil {
 		taskErr = service.TaskErrorWrapper(errors.Wrap(err, fmt.Sprintf("%s", responseBody)), "unmarshal_response_failed", http.StatusInternalServerError)
 		return
@@ -180,8 +180,8 @@ func (a *TaskAdaptor) DoResponse(c *gin.Context, resp *http.Response, info *rela
 	}
 
 	ov := dto.NewOpenAIVideo()
-	ov.ID = vResp.TaskId
-	ov.TaskID = vResp.TaskId
+	ov.ID = info.PublicTaskID
+	ov.TaskID = info.PublicTaskID
 	ov.CreatedAt = time.Now().Unix()
 	ov.Model = info.OriginModelName
 	c.JSON(http.StatusOK, ov)
@@ -225,45 +225,25 @@ func (a *TaskAdaptor) GetChannelName() string {
 
 func (a *TaskAdaptor) convertToRequestPayload(req *relaycommon.TaskSubmitReq) (*requestPayload, error) {
 	r := requestPayload{
-		Model:             defaultString(req.Model, "viduq1"),
+		Model:             taskcommon.DefaultString(req.Model, "viduq1"),
 		Images:            req.Images,
 		Prompt:            req.Prompt,
-		Duration:          defaultInt(req.Duration, 5),
-		Resolution:        defaultString(req.Size, "1080p"),
+		Duration:          taskcommon.DefaultInt(req.Duration, 5),
+		Resolution:        taskcommon.DefaultString(req.Size, "1080p"),
 		MovementAmplitude: "auto",
 		Bgm:               false,
 	}
-	metadata := req.Metadata
-	medaBytes, err := json.Marshal(metadata)
-	if err != nil {
-		return nil, errors.Wrap(err, "metadata marshal metadata failed")
-	}
-	err = json.Unmarshal(medaBytes, &r)
-	if err != nil {
+	if err := taskcommon.UnmarshalMetadata(req.Metadata, &r); err != nil {
 		return nil, errors.Wrap(err, "unmarshal metadata failed")
 	}
 	return &r, nil
 }
 
-func defaultString(value, defaultValue string) string {
-	if value == "" {
-		return defaultValue
-	}
-	return value
-}
-
-func defaultInt(value, defaultValue int) int {
-	if value == 0 {
-		return defaultValue
-	}
-	return value
-}
-
 func (a *TaskAdaptor) ParseTaskResult(respBody []byte) (*relaycommon.TaskInfo, error) {
 	taskInfo := &relaycommon.TaskInfo{}
 
 	var taskResp taskResultResponse
-	err := json.Unmarshal(respBody, &taskResp)
+	err := common.Unmarshal(respBody, &taskResp)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to unmarshal response body")
 	}
@@ -293,7 +273,7 @@ func (a *TaskAdaptor) ParseTaskResult(respBody []byte) (*relaycommon.TaskInfo, e
 
 func (a *TaskAdaptor) ConvertToOpenAIVideo(originTask *model.Task) ([]byte, error) {
 	var viduResp taskResultResponse
-	if err := json.Unmarshal(originTask.Data, &viduResp); err != nil {
+	if err := common.Unmarshal(originTask.Data, &viduResp); err != nil {
 		return nil, errors.Wrap(err, "unmarshal vidu task data failed")
 	}
 
@@ -315,6 +295,5 @@ func (a *TaskAdaptor) ConvertToOpenAIVideo(originTask *model.Task) ([]byte, erro
 		}
 	}
 
-	jsonData, _ := common.Marshal(openAIVideo)
-	return jsonData, nil
+	return common.Marshal(openAIVideo)
 }