feat: 新增技能编排引擎和工作流构建器组件

refactor: 统一Hands系统常量到单个源文件
refactor: 更新Hands中文名称和描述

fix: 修复技能市场在连接状态变化时重新加载
fix: 修复身份变更提案的错误处理逻辑

docs: 更新多个功能文档的验证状态和实现位置
docs: 更新Hands系统文档

test: 添加测试文件验证工作区路径

desktop/src/components/WorkflowBuilder/nodes/ExportNode.tsx

@@ -0,0 +1,72 @@
+/**
+ * Export Node Component
+ *
+ * Node for exporting workflow results to various formats.
+ */
+
+import React, { memo } from 'react';
+import { Handle, Position, NodeProps } from '@xyflow/react';
+import type { ExportNodeData } from '../../../lib/workflow-builder/types';
+
+export const ExportNode = memo(({ data, selected }: NodeProps<ExportNodeData>) => {
+  const formatLabels: Record<string, string> = {
+    pptx: 'PowerPoint',
+    html: 'HTML',
+    pdf: 'PDF',
+    markdown: 'Markdown',
+    json: 'JSON',
+  };
+
+  return (
+    <div
+      className={`
+        px-4 py-3 rounded-lg border-2 min-w-[180px]
+        bg-blue-50 border-blue-300
+        ${selected ? 'border-blue-500 shadow-lg shadow-blue-200' : ''}
+      `}
+    >
+      {/* Input Handle */}
+      <Handle
+        type="target"
+        position={Position.Left}
+        className="w-3 h-3 bg-blue-400 border-2 border-white"
+      />
+
+      {/* Output Handle */}
+      <Handle
+        type="source"
+        position={Position.Right}
+        className="w-3 h-3 bg-blue-500 border-2 border-white"
+      />
+
+      {/* Header */}
+      <div className="flex items-center gap-2 mb-2">
+        <span className="text-lg">📤</span>
+        <span className="font-medium text-blue-800">{data.label}</span>
+      </div>
+
+      {/* Formats */}
+      <div className="flex flex-wrap gap-1">
+        {data.formats.map((format) => (
+          <span
+            key={format}
+            className="text-xs bg-blue-100 text-blue-700 px-2 py-0.5 rounded"
+          >
+            {formatLabels[format] || format}
+          </span>
+        ))}
+      </div>
+
+      {/* Output Directory */}
+      {data.outputDir && (
+        <div className="text-xs text-blue-500 mt-2 truncate">
+          📁 {data.outputDir}
+        </div>
+      )}
+    </div>
+  );
+});
+
+ExportNode.displayName = 'ExportNode';
+
+export default ExportNode;