fix: stop pointer/mouse event propagation in vueNodes widget containers (#7953)

## Summary
Prevents custom widget drag interactions from triggering node drag in
vueNodes mode. Custom plugins like KJNodes Points Editor use their own
drag handlers which were bubbling up to the node container.

## Screenshots (if applicable)
before



https://github.com/user-attachments/assets/bc4c3095-d454-45f6-a4ec-60178e8f47df


after


https://github.com/user-attachments/assets/a32a5591-120e-4842-a0e0-3dd972127376

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7953-fix-stop-pointer-mouse-event-propagation-in-vueNodes-widget-containers-2e56d73d3650810398f2c582a91d767b)
by [Unito](https://www.unito.io)

src/renderer/extensions/vueNodes/widgets/components/WidgetDOM.vue

@@ -24,5 +24,13 @@ onMounted(() => {
 })
 </script>
 <template>
-  <div ref="domEl" />
+  <div
+    ref="domEl"
+    @pointerdown.stop
+    @pointermove.stop
+    @pointerup.stop
+    @mousedown.stop
+    @mousemove.stop
+    @mouseup.stop
+  />
 </template>

src/renderer/extensions/vueNodes/widgets/components/WidgetLegacy.vue

@@ -105,9 +105,9 @@ function handleMove(e: PointerEvent) {
     <canvas
       ref="canvasEl"
       class="absolute w-full cursor-crosshair"
-      @pointerdown="handleDown"
-      @pointerup="handleUp"
-      @pointermove="handleMove"
+      @pointerdown.stop="handleDown"
+      @pointerup.stop="handleUp"
+      @pointermove.stop="handleMove"
     />
   </div>
 </template>