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/gemini/adaptor.go

@@ -2,8 +2,6 @@ package gemini
 
 import (
 	"bytes"
-	"encoding/base64"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -16,10 +14,10 @@ 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"
 	"github.com/QuantumNous/new-api/setting/model_setting"
-	"github.com/QuantumNous/new-api/setting/system_setting"
 	"github.com/gin-gonic/gin"
 	"github.com/pkg/errors"
 )
@@ -145,16 +143,11 @@ func (a *TaskAdaptor) BuildRequestBody(c *gin.Context, info *relaycommon.RelayIn
 	}
 
 	metadata := req.Metadata
-	medaBytes, err := json.Marshal(metadata)
-	if err != nil {
-		return nil, errors.Wrap(err, "metadata marshal metadata failed")
-	}
-	err = json.Unmarshal(medaBytes, &body.Parameters)
-	if err != nil {
+	if err := taskcommon.UnmarshalMetadata(metadata, &body.Parameters); err != nil {
 		return nil, errors.Wrap(err, "unmarshal metadata failed")
 	}
 
-	data, err := json.Marshal(body)
+	data, err := common.Marshal(body)
 	if err != nil {
 		return nil, err
 	}
@@ -175,16 +168,16 @@ func (a *TaskAdaptor) DoResponse(c *gin.Context, resp *http.Response, info *rela
 	_ = resp.Body.Close()
 
 	var s submitResponse
-	if err := json.Unmarshal(responseBody, &s); err != nil {
+	if err := common.Unmarshal(responseBody, &s); err != nil {
 		return "", nil, service.TaskErrorWrapper(err, "unmarshal_response_failed", http.StatusInternalServerError)
 	}
 	if strings.TrimSpace(s.Name) == "" {
 		return "", nil, service.TaskErrorWrapper(fmt.Errorf("missing operation name"), "invalid_response", http.StatusInternalServerError)
 	}
-	taskID = encodeLocalTaskID(s.Name)
+	taskID = taskcommon.EncodeLocalTaskID(s.Name)
 	ov := dto.NewOpenAIVideo()
-	ov.ID = taskID
-	ov.TaskID = taskID
+	ov.ID = info.PublicTaskID
+	ov.TaskID = info.PublicTaskID
 	ov.CreatedAt = time.Now().Unix()
 	ov.Model = info.OriginModelName
 	c.JSON(http.StatusOK, ov)
@@ -206,7 +199,7 @@ func (a *TaskAdaptor) FetchTask(baseUrl, key string, body map[string]any, proxy
 		return nil, fmt.Errorf("invalid task_id")
 	}
 
-	upstreamName, err := decodeLocalTaskID(taskID)
+	upstreamName, err := taskcommon.DecodeLocalTaskID(taskID)
 	if err != nil {
 		return nil, fmt.Errorf("decode task_id failed: %w", err)
 	}
@@ -232,7 +225,7 @@ func (a *TaskAdaptor) FetchTask(baseUrl, key string, body map[string]any, proxy
 
 func (a *TaskAdaptor) ParseTaskResult(respBody []byte) (*relaycommon.TaskInfo, error) {
 	var op operationResponse
-	if err := json.Unmarshal(respBody, &op); err != nil {
+	if err := common.Unmarshal(respBody, &op); err != nil {
 		return nil, fmt.Errorf("unmarshal operation response failed: %w", err)
 	}
 
@@ -254,9 +247,8 @@ func (a *TaskAdaptor) ParseTaskResult(respBody []byte) (*relaycommon.TaskInfo, e
 	ti.Status = model.TaskStatusSuccess
 	ti.Progress = "100%"
 
-	taskID := encodeLocalTaskID(op.Name)
-	ti.TaskID = taskID
-	ti.Url = fmt.Sprintf("%s/v1/videos/%s/content", system_setting.ServerAddress, taskID)
+	ti.TaskID = taskcommon.EncodeLocalTaskID(op.Name)
+	// Url intentionally left empty — the caller constructs the proxy URL using the public task ID
 
 	// Extract URL from generateVideoResponse if available
 	if len(op.Response.GenerateVideoResponse.GeneratedSamples) > 0 {
@@ -269,7 +261,10 @@ func (a *TaskAdaptor) ParseTaskResult(respBody []byte) (*relaycommon.TaskInfo, e
 }
 
 func (a *TaskAdaptor) ConvertToOpenAIVideo(task *model.Task) ([]byte, error) {
-	upstreamName, err := decodeLocalTaskID(task.TaskID)
+	// Use GetUpstreamTaskID() to get the real upstream operation name for model extraction.
+	// task.TaskID is now a public task_xxxx ID, no longer a base64-encoded upstream name.
+	upstreamTaskID := task.GetUpstreamTaskID()
+	upstreamName, err := taskcommon.DecodeLocalTaskID(upstreamTaskID)
 	if err != nil {
 		upstreamName = ""
 	}
@@ -297,18 +292,6 @@ func (a *TaskAdaptor) ConvertToOpenAIVideo(task *model.Task) ([]byte, error) {
 // helpers
 // ============================
 
-func encodeLocalTaskID(name string) string {
-	return base64.RawURLEncoding.EncodeToString([]byte(name))
-}
-
-func decodeLocalTaskID(local string) (string, error) {
-	b, err := base64.RawURLEncoding.DecodeString(local)
-	if err != nil {
-		return "", err
-	}
-	return string(b), nil
-}
-
 var modelRe = regexp.MustCompile(`models/([^/]+)/operations/`)
 
 func extractModelFromOperationName(name string) string {