fix: preserve Vue node reactivity during undo/redo operations (#7222)

## Summary
preserve Vue node reactivity during undo/redo operations

Root Cause: The Vue reactivity chain was broken during undo/redo
operations:
1. handleDeleteNode was deleting nodeRefs and nodeTriggers
2. Vue components still held references to the old refs
3. When nodes were recreated, finalizeOperation tried to call triggers
but they were already deleted
4. Vue didn't know the data had changed, so nodes didn't visually update

fix https://github.com/Comfy-Org/ComfyUI_frontend/issues/7040

## Screenshots


https://github.com/user-attachments/assets/2feb294a-36e8-4bbe-b3f7-b7015066abc5

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7222-fix-preserve-Vue-node-reactivity-during-undo-redo-operations-2c36d73d3650819ab72afb10cbdaf39a)
by [Unito](https://www.unito.io)

src/renderer/extensions/vueNodes/layout/useNodeLayout.ts

@@ -1,4 +1,4 @@
-import { computed, toValue } from 'vue'
+import { computed, onUnmounted, toValue } from 'vue'
 import type { MaybeRefOrGetter } from 'vue'
 
 import { useLayoutMutations } from '@/renderer/core/layout/operations/layoutMutations'
@@ -17,6 +17,11 @@ export function useNodeLayout(nodeIdMaybe: MaybeRefOrGetter<string>) {
   // Get the customRef for this node (shared write access)
   const layoutRef = layoutStore.getNodeLayoutRef(nodeId)
 
+  // Clean up refs and triggers when Vue component unmounts
+  onUnmounted(() => {
+    layoutStore.cleanupNodeRef(nodeId)
+  })
+
   // Computed properties for easy access
   const position = computed(() => {
     const layout = layoutRef.value