fix: disable pointer events on non-visible DOM widget overlays (#11063)

## Problem

When a node with DOM widget overlays (e.g. CLIPTextEncode) is collapsed,
the overlay elements can intercept pointer events intended for the
canvas collapse toggler, making click-to-expand unreliable.

## Root Cause

`updateWidgets()` runs during `onDrawForeground` (canvas render cycle)
and sets `widgetState.visible = false` for collapsed nodes. `v-show`
then hides the element with `display: none`. However, there is a timing
gap between the canvas state change and Vue's DOM update — during this
gap the widget overlay still intercepts pointer events.

## Fix

Add `!widgetState.visible` to the `pointerEvents` condition in
`composeStyle()`. This immediately sets `pointer-events: none` when the
widget becomes invisible, preventing event interception before `v-show`
applies `display: none`.

Also restores click-to-expand in the E2E test, removing the programmatic
`node.collapse()` workaround from PR #10967.

- Fixes #11006

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-11063-fix-disable-pointer-events-on-non-visible-DOM-widget-overlays-33e6d73d36508179a83cd47121cf933f)
by [Unito](https://www.unito.io)

src/components/graph/widgets/DomWidget.vue

@@ -113,7 +113,10 @@ function composeStyle() {
     ...positionStyle.value,
     ...(enableDomClipping.value ? clippingStyle.value : {}),
     zIndex: widgetState.zIndex,
-    pointerEvents: widgetState.readonly || isDisabled ? 'none' : 'auto',
+    pointerEvents:
+      !widgetState.visible || widgetState.readonly || isDisabled
+        ? 'none'
+        : 'auto',
     opacity: isDisabled ? 0.5 : 1
   }
 }