Check if the wheel event is from an element that wants to capture wheel events (#5821)

## Summary

Add generic wheel event capture mechanism for interactive widgets in
vueNodes system to prevent event bubbling to canvas.

  ## Changes

- What: Add event handling logic in LGraphNode.vue and GraphCanvas.vue
that checks for data-capture-wheel attribute to determine whether wheel
events should be forwarded to the canvas
- How it works: Components that need to capture wheel events (like
Three.js scenes) can add data-capture-wheel="true" attribute to prevent
wheel events from bubbling up to the canvas zoom handler

prerequirist for https://github.com/Comfy-Org/ComfyUI_frontend/pull/5765

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5821-Check-if-the-wheel-event-is-from-an-element-that-wants-to-capture-wheel-events-27b6d73d3650812493b5f13849147e6c)
by [Unito](https://www.unito.io)

src/renderer/core/canvas/useCanvasInteractions.ts

@@ -30,6 +30,15 @@ export function useCanvasInteractions() {
    * when appropriate (e.g., Ctrl+wheel for zoom in standard mode)
    */
   const handleWheel = (event: WheelEvent) => {
+    // Check if the wheel event is from an element that wants to capture wheel events
+    const target = event.target as HTMLElement
+    const captureElement = target?.closest('[data-capture-wheel="true"]')
+
+    if (captureElement) {
+      // Element wants to capture wheel events, don't forward to canvas
+      return
+    }
+
     // In standard mode, Ctrl+wheel should go to canvas for zoom
     if (isStandardNavMode.value && (event.ctrlKey || event.metaKey)) {
       forwardEventToCanvas(event)
@@ -72,6 +81,15 @@ export function useCanvasInteractions() {
   const forwardEventToCanvas = (
     event: WheelEvent | PointerEvent | MouseEvent
   ) => {
+    // Check if the wheel event is from an element that wants to capture wheel events
+    const target = event.target as HTMLElement
+    const captureElement = target?.closest('[data-capture-wheel="true"]')
+
+    if (captureElement) {
+      // Element wants to capture wheel events, don't forward to canvas
+      return
+    }
+
     const canvasEl = app.canvas?.canvas
     if (!canvasEl) return
     event.preventDefault()

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

@@ -23,6 +23,7 @@
           onBlur: handleBlur
         }
       }"
+      data-capture-wheel="true"
       @update:model-value="onChange"
       @click.stop
       @keydown.stop

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

@@ -10,6 +10,7 @@
       :pt="{
         option: 'text-xs'
       }"
+      data-capture-wheel="true"
       @update:model-value="onChange"
     />
   </WidgetLayoutField>

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

@@ -8,6 +8,7 @@
       :placeholder="placeholder || widget.name || ''"
       size="small"
       rows="3"
+      data-capture-wheel="true"
       @update:model-value="onChange"
     />
     <LODFallback />