fix: seedance metadata override prompt

relay/channel/task/doubao/adaptor.go

@@ -224,14 +224,6 @@ func (a *TaskAdaptor) convertToRequestPayload(req *relaycommon.TaskSubmitReq) (*
 		Content: []ContentItem{},
 	}
 
-	// Add text prompt
-	if req.Prompt != "" {
-		r.Content = append(r.Content, ContentItem{
-			Type: "text",
-			Text: req.Prompt,
-		})
-	}
-
 	// Add images if present
 	if req.HasImage() {
 		for _, imgURL := range req.Images {
@@ -249,6 +241,14 @@ func (a *TaskAdaptor) convertToRequestPayload(req *relaycommon.TaskSubmitReq) (*
 		return nil, errors.Wrap(err, "unmarshal metadata failed")
 	}
 
+	// Add text prompt
+	if req.Prompt != "" {
+		r.Content = append(r.Content, ContentItem{
+			Type: "text",
+			Text: req.Prompt,
+		})
+	}
+
 	return &r, nil
 }