perf: 减少工作流设计器重复计算与序列化

- 缓存节点汇聚模式拓扑分析结果

- 草稿保存复用内容序列化结果

easyflow-ui-admin/app/src/views/ai/workflow/__tests__/workflowDraftCache.test.ts

@@ -114,6 +114,23 @@ describe('workflowDraftCache', () => {
     ).toBe(false);
   });
 
+  it('写入草稿时只序列化一次工作流内容', () => {
+    const toJSON = vi.fn(() => draftContent);
+
+    expect(
+      writeWorkflowDraft({
+        baseContentSignature: createWorkflowContentSignature(serverContent),
+        content: {toJSON},
+        workflowId,
+      }),
+    ).toBe(true);
+
+    expect(toJSON).toHaveBeenCalledTimes(1);
+    expect(readWorkflowDraft(workflowId, serverContent)?.content).toEqual(
+      draftContent,
+    );
+  });
+
   it('忽略结构异常的缓存内容', () => {
     sessionStorage.setItem(
       `easyflow:workflow-draft:${workflowId}`,

easyflow-ui-admin/app/src/views/ai/workflow/workflowDraftCache.ts

@@ -63,6 +63,25 @@ export function createWorkflowContentSignature(content: unknown) {
   }
 }
 
+function serializeWorkflowDraft(
+  options: WriteWorkflowDraftOptions,
+  contentSignature: string,
+) {
+  return [
+    '{"baseContentSignature":',
+    JSON.stringify(options.baseContentSignature),
+    ',"content":',
+    contentSignature,
+    ',"updatedAt":',
+    String(Date.now()),
+    ',"version":',
+    String(WORKFLOW_DRAFT_VERSION),
+    ',"workflowId":',
+    JSON.stringify(String(options.workflowId)),
+    '}',
+  ].join('');
+}
+
 export function readWorkflowDraft(
   workflowId: unknown,
   serverContent: unknown,
@@ -124,15 +143,11 @@ export function writeWorkflowDraft(
     return true;
   }
 
-  const snapshot: WorkflowDraftSnapshot = {
-    baseContentSignature: options.baseContentSignature,
-    content: options.content,
-    updatedAt: Date.now(),
-    version: WORKFLOW_DRAFT_VERSION,
-    workflowId: String(options.workflowId),
-  };
   try {
-    storage.setItem(storageKey, JSON.stringify(snapshot));
+    storage.setItem(
+      storageKey,
+      serializeWorkflowDraft(options, contentSignature),
+    );
     return true;
   } catch {
     return false;