Fix/vue nodes auto scale (#6664)

## Summary

**Problem:** ensureCorrectLayoutScale scales up LG -> Vue. But doesn't
scale down from Vue -> LG.

**Solution:** Bi directional scaling.

**Bonus:** fix edge cases such as subgraphs, groups, and reroutes. Also,
set auto scale: true now that we 'preserve' LG scale.

**IMPORTANT:** useVueNodeResizeTracking.ts sets vue node height -
Litegraph.NODE_TITLE_HEIGHT on workflow load using a resize observer.
Reloading the page (loading a workflow) in Vue mode, will subtract
height each time. This can look like a problem caused by
ensureCorrectLayoutScale. It is not. Need to fix. Here was an attempt by
[removing the Litegraph.NODE_TITLE_HEIGHT
entirely](https://github.com/Comfy-Org/ComfyUI_frontend/pull/6643).

## Review Focus

Full lifecycle of loading workflows and switching between vue and lg.
Race conditions could be present. For example switching the mode using
keybind very fast.

## Screenshots (if applicable)


https://github.com/user-attachments/assets/5576b760-13a8-45b9-b8f7-64e1caf443c1



https://github.com/user-attachments/assets/46d6f870-df76-4084-968a-53cb629fc123

---------

Co-authored-by: github-actions <github-actions@github.com>

src/composables/graph/useVueNodeLifecycle.ts

@@ -1,4 +1,4 @@
-import { createSharedComposable } from '@vueuse/core'
+import { createSharedComposable, whenever } from '@vueuse/core'
 import { shallowRef, watch } from 'vue'
 
 import { useGraphNodeManager } from '@/composables/graph/useGraphNodeManager'
@@ -82,8 +82,9 @@ function useVueNodeLifecycleIndividual() {
     (enabled, wasEnabled) => {
       if (enabled) {
         initializeNodeManager()
-        ensureCorrectLayoutScale()
-
+        ensureCorrectLayoutScale(
+          comfyApp.canvas?.graph?.extra.workflowRendererVersion
+        )
         if (!wasEnabled && !isVueNodeToastDismissed.value) {
           useToastStore().add({
             group: 'vue-nodes-migration',
@@ -91,14 +92,22 @@ function useVueNodeLifecycleIndividual() {
             life: 0
           })
         }
-      } else {
-        comfyApp.canvas?.setDirty(true, true)
-        disposeNodeManagerAndSyncs()
       }
     },
     { immediate: true }
   )
 
+  whenever(
+    () => !shouldRenderVueNodes.value,
+    () => {
+      ensureCorrectLayoutScale(
+        comfyApp.canvas?.graph?.extra.workflowRendererVersion
+      )
+      disposeNodeManagerAndSyncs()
+      comfyApp.canvas?.setDirty(true, true)
+    }
+  )
+
   // Consolidated watch for slot layout sync management
   watch(
     () => shouldRenderVueNodes.value,