fix: correct Vue node selection box detection accuracy (#7741)

## Summary
Remove double-counting of NODE_TITLE_HEIGHT in layout sync. The title
height was being added both in useLayoutSync and in LiteGraph's
measure() function, causing boundingRect to be 30px taller than actual
DOM.

This caused selection box to detect nodes ~30px below their actual
bottom.

fix https://github.com/Comfy-Org/ComfyUI_frontend/issues/7580

## Screenshots (if applicable)
before


https://github.com/user-attachments/assets/babf0b9d-174e-4ec3-a3bb-18e4f9d88d09

after


https://github.com/user-attachments/assets/4f9989a5-4d3c-4303-bd1b-70ca70cb8f15

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7741-fix-correct-Vue-node-selection-box-detection-accuracy-2d26d73d3650817cbe80f98a3bf1abf1)
by [Unito](https://www.unito.io)

---------

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

src/renderer/core/layout/sync/useLayoutSync.ts

@@ -8,7 +8,6 @@ import { onUnmounted, ref } from 'vue'
 
 import type { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { layoutStore } from '@/renderer/core/layout/store/layoutStore'
-import { addNodeTitleHeight } from '@/renderer/core/layout/utils/nodeSizeUtil'
 
 /**
  * Composable for syncing LiteGraph with the Layout system
@@ -44,13 +43,15 @@ export function useLayoutSync() {
           liteNode.pos[1] = layout.position.y
         }
 
-        const targetHeight = addNodeTitleHeight(layout.size.height)
+        // Note: layout.size.height is the content height without title.
+        // LiteGraph's measure() will add titleHeight to get boundingRect.
+        // Do NOT use addNodeTitleHeight here - that would double-count the title.
         if (
           liteNode.size[0] !== layout.size.width ||
-          liteNode.size[1] !== targetHeight
+          liteNode.size[1] !== layout.size.height
         ) {
           // Use setSize() to trigger onResize callback
-          liteNode.setSize([layout.size.width, targetHeight])
+          liteNode.setSize([layout.size.width, layout.size.height])
         }
       }
 

src/renderer/core/layout/utils/nodeSizeUtil.ts

@@ -2,6 +2,3 @@ import { LiteGraph } from '@/lib/litegraph/src/litegraph'
 
 export const removeNodeTitleHeight = (height: number) =>
   Math.max(0, height - (LiteGraph.NODE_TITLE_HEIGHT || 0))
-
-export const addNodeTitleHeight = (height: number) =>
-  height + LiteGraph.NODE_TITLE_HEIGHT