fix: simplify ensureCorrectLayoutScale and fix link sync during Vue node drag (#9680)

## Summary

Fix node layout drift from repeated `ensureCorrectLayoutScale` scaling,
simplify it to a pure one-time normalizer, and fix links not following
Vue nodes during drag.

## Changes

- **What**:
- `ensureCorrectLayoutScale` simplified to a one-time normalizer:
unprojects legacy Vue-scaled coordinates back to canonical LiteGraph
coordinates, marks the graph as corrected, and does nothing else. No
longer touches the layout store, syncs reroutes, or changes canvas
scale.
- Removed no-op calls from `useVueNodeLifecycle.ts` (a renderer version
string was passed where an `LGraph` was expected).
- `layoutStore.finalizeOperation` now calls `notifyChange` synchronously
instead of via `setTimeout`. This ensures `useLayoutSync`'s `onChange`
callback pushes positions to LiteGraph `node.pos` and calls
`canvas.setDirty()` within the same RAF frame as a drag update, fixing
links not following Vue nodes during drag.
- **Tests**: Added tests for `ensureCorrectLayoutScale` (idempotency,
round-trip, unknown-renderer no-op) and `graphRenderTransform`
(project/unproject round-trips, anchor caching).

## Review Focus

- The `setTimeout(() => this.notifyChange(change), 0)` →
`this.notifyChange(change)` change in `layoutStore.ts` is the key fix
for the drag-link-sync bug. The listener (`useLayoutSync`) only writes
to LiteGraph, not back to the layout store, so synchronous notification
is safe.
- `ensureCorrectLayoutScale` no longer has any side effects beyond
normalizing coordinates and setting `workflowRendererVersion` metadata.

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: Christian Byrne <cbyrne@comfy.org>
Co-authored-by: jaeone94 <89377375+jaeone94@users.noreply.github.com>
Co-authored-by: AustinMroz <austin@comfy.org>
Co-authored-by: Hunter <huntcsg@users.noreply.github.com>
Co-authored-by: GitHub Action <action@github.com>

src/composables/graph/useVueNodeLifecycle.ts

@@ -9,7 +9,6 @@ import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { useLayoutMutations } from '@/renderer/core/layout/operations/layoutMutations'
 import { layoutStore } from '@/renderer/core/layout/store/layoutStore'
 import { useLayoutSync } from '@/renderer/core/layout/sync/useLayoutSync'
-import { ensureCorrectLayoutScale } from '@/renderer/extensions/vueNodes/layout/ensureCorrectLayoutScale'
 import { app as comfyApp } from '@/scripts/app'
 
 function useVueNodeLifecycleIndividual() {
@@ -17,7 +16,7 @@ function useVueNodeLifecycleIndividual() {
   const layoutMutations = useLayoutMutations()
   const { shouldRenderVueNodes } = useVueFeatureFlags()
   const nodeManager = shallowRef<GraphNodeManager | null>(null)
-  const { startSync } = useLayoutSync()
+  const { startSync, stopSync } = useLayoutSync()
 
   const initializeNodeManager = () => {
     // Use canvas graph if available (handles subgraph contexts), fallback to app graph
@@ -55,11 +54,13 @@ function useVueNodeLifecycleIndividual() {
       )
     }
 
-    // Initialize layout sync (one-way: Layout Store → LiteGraph)
+    // Start sync AFTER seeding so bootstrap operations don't trigger
+    // the Layout→LiteGraph writeback loop redundantly.
     startSync(canvasStore.canvas)
   }
 
   const disposeNodeManagerAndSyncs = () => {
+    stopSync()
     if (!nodeManager.value) return
 
     try {
@@ -76,9 +77,6 @@ function useVueNodeLifecycleIndividual() {
     (enabled) => {
       if (enabled) {
         initializeNodeManager()
-        ensureCorrectLayoutScale(
-          comfyApp.canvas?.graph?.extra.workflowRendererVersion
-        )
       }
     },
     { immediate: true }
@@ -87,26 +85,17 @@ function useVueNodeLifecycleIndividual() {
   whenever(
     () => !shouldRenderVueNodes.value,
     () => {
-      ensureCorrectLayoutScale(
-        comfyApp.canvas?.graph?.extra.workflowRendererVersion
-      )
       disposeNodeManagerAndSyncs()
       comfyApp.canvas?.setDirty(true, true)
     }
   )
 
-  // Consolidated watch for slot layout sync management
+  // Clear stale slot layouts when switching modes
   watch(
     () => shouldRenderVueNodes.value,
-    (vueMode, oldVueMode) => {
-      const modeChanged = vueMode !== oldVueMode
-
-      // Clear stale slot layouts when switching modes
-      if (modeChanged) {
-        layoutStore.clearAllSlotLayouts()
-      }
-    },
-    { immediate: true, flush: 'sync' }
+    () => {
+      layoutStore.clearAllSlotLayouts()
+    }
   )
 
   // Handle case where Vue nodes are enabled but graph starts empty