feat: show ComfyUI context menu on textarea widget right-click (#9840)

## Summary

Right-clicking a textarea widget (e.g. text node) shows the browser's
native context menu instead of ComfyUI's context menu, preventing access
to promote/un-promote options in subgraphs.

## Changes

- **What**: Replace `@contextmenu.capture.stop` on
`WidgetTextarea.vue`'s `<Textarea>` with a handler implementing
double-right-click toggling: first right-click shows ComfyUI's context
menu, second right-click (while menu is open) allows browser native
menu. Exposes `isNodeOptionsOpen()` from `useMoreOptionsMenu.ts` to
check menu state.

## Review Focus

The capture-phase handler in `WidgetTextarea.vue` only changes
`contextmenu` handling — pointer event modifiers
(`pointerdown/move/up.capture.stop`) that prevent canvas panning are
untouched. The double-right-click pattern matches Notion/YouTube
behavior for editable text fields.

<!-- Pipeline-Ticket: d7a53160-e1e1-42bb-a5ac-c0c2702c629c -->

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9840-fix-show-ComfyUI-context-menu-on-textarea-widget-right-click-3216d73d36508102b4c9c13a5915bc48)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>

src/renderer/extensions/vueNodes/widgets/components/WidgetTextarea.test.ts

@@ -7,6 +7,7 @@ import WidgetTextarea from './WidgetTextarea.vue'
 import { createMockWidget } from './widgetTestUtils'
 
 const mockCopyToClipboard = vi.hoisted(() => vi.fn())
+const mockIsNodeOptionsOpen = vi.hoisted(() => vi.fn(() => false))
 
 vi.mock('@/composables/useCopyToClipboard', () => ({
   useCopyToClipboard: vi.fn().mockReturnValue({
@@ -14,6 +15,10 @@ vi.mock('@/composables/useCopyToClipboard', () => ({
   })
 }))
 
+vi.mock('@/composables/graph/useMoreOptionsMenu', () => ({
+  isNodeOptionsOpen: mockIsNodeOptionsOpen
+}))
+
 function createTextareaWidget(
   value: string = 'default text',
   options: SimplifiedWidget<string>['options'] = {},
@@ -277,3 +282,43 @@ describe('WidgetTextarea Value Binding', () => {
     })
   })
 })
+
+describe('WidgetTextarea contextmenu', () => {
+  it('prevents browser menu on first right-click (menu closed)', () => {
+    mockIsNodeOptionsOpen.mockReturnValue(false)
+    const widget = createTextareaWidget('test')
+    const wrapper = mountComponent(widget, 'test')
+    const textarea = wrapper.find('textarea')
+
+    const event = new MouseEvent('contextmenu', {
+      bubbles: true,
+      cancelable: true
+    })
+    const preventDefaultSpy = vi.spyOn(event, 'preventDefault')
+    const stopPropagationSpy = vi.spyOn(event, 'stopPropagation')
+
+    textarea.element.dispatchEvent(event)
+
+    expect(preventDefaultSpy).toHaveBeenCalled()
+    expect(stopPropagationSpy).not.toHaveBeenCalled()
+  })
+
+  it('allows browser menu on second right-click (menu open)', () => {
+    mockIsNodeOptionsOpen.mockReturnValue(true)
+    const widget = createTextareaWidget('test')
+    const wrapper = mountComponent(widget, 'test')
+    const textarea = wrapper.find('textarea')
+
+    const event = new MouseEvent('contextmenu', {
+      bubbles: true,
+      cancelable: true
+    })
+    const preventDefaultSpy = vi.spyOn(event, 'preventDefault')
+    const stopPropagationSpy = vi.spyOn(event, 'stopPropagation')
+
+    textarea.element.dispatchEvent(event)
+
+    expect(preventDefaultSpy).not.toHaveBeenCalled()
+    expect(stopPropagationSpy).toHaveBeenCalled()
+  })
+})