되돌리기 기능 추가

frontend/components/dataflow/node-editor/FlowToolbar.tsx

@@ -25,6 +25,10 @@ export function FlowToolbar() {
     isSaving,
     selectedNodes,
     removeNodes,
+    undo,
+    redo,
+    canUndo,
+    canRedo,
   } = useFlowEditorStore();
   const [showLoadDialog, setShowLoadDialog] = useState(false);
 
@@ -108,10 +112,10 @@ export function FlowToolbar() {
         <div className="h-6 w-px bg-gray-200" />
 
         {/* 실행 취소/다시 실행 */}
-        <Button variant="ghost" size="sm" title="실행 취소" disabled>
+        <Button variant="ghost" size="sm" title="실행 취소 (Ctrl+Z)" disabled={!canUndo()} onClick={undo}>
           <Undo2 className="h-4 w-4" />
         </Button>
-        <Button variant="ghost" size="sm" title="다시 실행" disabled>
+        <Button variant="ghost" size="sm" title="다시 실행 (Ctrl+Y)" disabled={!canRedo()} onClick={redo}>
           <Redo2 className="h-4 w-4" />
         </Button>