fix(canvas): 画布智能体 - 严格校验模型选择并修正任务与 DNS 错误诊断

backend/internal/app/cloud_agent_media.go

@@ -538,7 +538,10 @@ func (s *Service) fillCloudAgentMediaSnapshotHash(userID, canvasID string, a *cl
 func (s *Service) prepareCloudAgentMedia(run *model.CloudAgentExecution, state *cloudAgentRuntime, call cloudAgentCall) (CreateTaskRequest, *cloudAgentMediaPlan, error) {
 	var a cloudAgentMediaArgs
 	if err := decodeCloudAgentJSONObject(call.Function.Arguments, &a); err != nil {
-		return CreateTaskRequest{}, nil, BadAuthRequest("生成参数必须是只含支持字段的单个JSON对象")
+		return CreateTaskRequest{}, nil, cloudAgentJSONArgumentError(err)
+	}
+	if err := validateCloudAgentModelSelection(call.Function.Arguments, a); err != nil {
+		return CreateTaskRequest{}, nil, err
 	}
 	a.Mode = strings.ToLower(strings.TrimSpace(a.Mode))
 	a.DraftRunID = run.ID
@@ -551,9 +554,6 @@ func (s *Service) prepareCloudAgentMedia(run *model.CloudAgentExecution, state *
 	if err := validateCloudAgentMediaArgs(a, state); err != nil {
 		return CreateTaskRequest{}, nil, err
 	}
-	if (a.LogicalModelID == "" && (a.ChannelID == "" || a.ChannelModelKey == "")) || (a.LogicalModelID != "" && (a.ChannelID != "" || a.ChannelModelKey != "")) {
-		return CreateTaskRequest{}, nil, BadAuthRequest("请复制 model_list 的 selection：逻辑模型或系统渠道二选一，不得混用")
-	}
 	_, _, refs, err := cloudAgentMediaDocument(s.repo, run.UserID, state.Request.CanvasID, a, state.TransientReferences)
 	if err != nil {
 		return CreateTaskRequest{}, nil, err