refactor(workflow): streamline workflow settings management

- Introduced new utility functions `settingsFromWorkflowGraph` and `workflowGraphWithSettings` to encapsulate settings extraction and graph updates.
- Updated `useWorkflowEditorState` to utilize the new utility functions for improved clarity and maintainability.
- Refactored `AssistantPage` and `WorkflowCanvas` components to leverage the new settings management functions, ensuring consistent handling of workflow settings across the application.
- Removed redundant settings handling code, enhancing overall code cleanliness.

frontend/src/components/pages/AssistantPage.tsx

@@ -53,6 +53,7 @@ import {
   type TurnConfig,
 } from "@/lib/api";
 import type { WorkflowSettings } from "@/components/workflow/types";
+import { workflowGraphWithSettings } from "@/components/workflow/graph-settings";
 import { SectionCard } from "@/components/editor/section-card";
 import {
   defaultGraph,
@@ -571,7 +572,6 @@ export function AssistantPage(props: AssistantPageProps) {
           JSON.stringify({
             name: workflowName,
             graph: workflowGraph,
-            settings: workflowSettings,
             dynamicVariableDefinitions: effectiveWorkflowDynamicVariableDefinitions,
           }),
         );
@@ -721,12 +721,14 @@ export function AssistantPage(props: AssistantPageProps) {
               graph.settings?.turnConfig ?? assistant.turnConfig,
             ),
           };
+          // 编辑器会把兼容字段和默认值写回 graph。状态与保存基线必须使用
+          // 同一个规范化结果，否则页面刚打开就会被误判为有未保存改动。
+          const normalizedGraph = workflowGraphWithSettings(graph, wfSettings);
           setWorkflowName(assistant.name);
-          setWorkflowGraph(graph);
-          setWorkflowSettings(wfSettings);
+          setWorkflowGraph(normalizedGraph);
           const dynamicVariableDefinitions =
             activeWorkflowDynamicVariableDefinitions(
-              graph,
+              normalizedGraph,
               assistant.dynamicVariableDefinitions ?? {},
             );
           setWorkflowDynamicVariableDefinitions(
@@ -735,8 +737,7 @@ export function AssistantPage(props: AssistantPageProps) {
           setSavedSnapshot(
             JSON.stringify({
               name: assistant.name,
-              graph,
-              settings: wfSettings,
+              graph: normalizedGraph,
               dynamicVariableDefinitions,
             }),
           );
@@ -818,7 +819,6 @@ export function AssistantPage(props: AssistantPageProps) {
             ? JSON.stringify({
                 name: workflowName,
                 graph: workflowGraph,
-                settings: workflowSettings,
                 dynamicVariableDefinitions:
                   effectiveWorkflowDynamicVariableDefinitions,
               })