[backport core/1.35] fix: collapsed nodes getting extra height based on contents (#7530)

Backport of #7490 to `core/1.35`

Automatically created by backport workflow.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7530-backport-core-1-35-fix-collapsed-nodes-getting-extra-height-based-on-contents-2ca6d73d3650810ebc93e4b39710d2f3)
by [Unito](https://www.unito.io)

Co-authored-by: Rizumu Ayaka <rizumu@ayaka.moe>

src/renderer/extensions/vueNodes/components/LGraphNode.vue

@@ -297,19 +297,26 @@ const handleContextMenu = (event: MouseEvent) => {
 }
 
 onMounted(() => {
-  // Set initial DOM size from layout store, but respect intrinsic content minimum
-  if (size.value && nodeContainerRef.value) {
-    nodeContainerRef.value.style.setProperty(
-      '--node-width',
-      `${size.value.width}px`
-    )
-    nodeContainerRef.value.style.setProperty(
-      '--node-height',
-      `${size.value.height}px`
-    )
-  }
+  initSizeStyles()
 })
 
+/**
+ * Set initial DOM size from layout store, but respect intrinsic content minimum.
+ * Important: nodes can mount in a collapsed state, and the collapse watcher won't
+ * run initially. Match the collapsed runtime behavior by writing to the correct
+ * CSS variables on mount.
+ */
+function initSizeStyles() {
+  const el = nodeContainerRef.value
+  const { width, height } = size.value
+  if (!el) return
+
+  const suffix = isCollapsed.value ? '-x' : ''
+
+  el.style.setProperty(`--node-width${suffix}`, `${width}px`)
+  el.style.setProperty(`--node-height${suffix}`, `${height}px`)
+}
+
 const baseResizeHandleClasses =
   'absolute h-3 w-3 opacity-0 pointer-events-auto focus-visible:outline focus-visible:outline-2 focus-visible:outline-white/40'