feat: add reset-to-default for widget parameters in right side panel (#8861)

## Summary

Add per-widget and reset-all-parameters functionality to the right side
panel, allowing users to quickly revert widget values to their defaults.

## Changes

- **What**: Per-widget "Reset to default" option in the WidgetActions
overflow menu, plus a "Reset all parameters" button in each
SectionWidgets header. Defaults are derived from the InputSpec (explicit
default, then type-specific fallbacks: 0 for INT/FLOAT, false for
BOOLEAN, empty string for STRING, first option for COMBO).
- **Dependencies**: Builds on #8594 (WidgetValueStore) for reactive UI
updates after reset.

## Review Focus

- `getWidgetDefaultValue` fallback logic in `src/utils/widgetUtil.ts` —
are the type-specific defaults appropriate?
- Deep equality check (`isEqual`) for disabling the reset button when
the value already matches the default.
- Event flow: WidgetActions emits `resetToDefault` → WidgetItem forwards
→ SectionWidgets handles via `writeWidgetValue` (sets value, triggers
callback, marks canvas dirty).

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8861-feat-add-reset-to-default-for-widget-parameters-in-right-side-panel-3076d73d365081d1aa08d5b965a16cf4)
by [Unito](https://www.unito.io)

Co-authored-by: Terry Jia <terryjia88@gmail.com>

src/components/rightSidePanel/parameters/WidgetActions.test.ts

@@ -0,0 +1,209 @@
+import { createTestingPinia } from '@pinia/testing'
+import { mount } from '@vue/test-utils'
+import { setActivePinia } from 'pinia'
+import type { Slots } from 'vue'
+import { h } from 'vue'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { createI18n } from 'vue-i18n'
+
+import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
+import type { IBaseWidget } from '@/lib/litegraph/src/types/widgets'
+
+import WidgetActions from './WidgetActions.vue'
+
+const { mockGetInputSpecForWidget } = vi.hoisted(() => ({
+  mockGetInputSpecForWidget: vi.fn()
+}))
+
+vi.mock('@/stores/nodeDefStore', () => ({
+  useNodeDefStore: () => ({
+    getInputSpecForWidget: mockGetInputSpecForWidget
+  })
+}))
+
+vi.mock('@/renderer/core/canvas/canvasStore', () => ({
+  useCanvasStore: () => ({
+    canvas: { setDirty: vi.fn() }
+  })
+}))
+
+vi.mock('@/stores/workspace/favoritedWidgetsStore', () => ({
+  useFavoritedWidgetsStore: () => ({
+    isFavorited: vi.fn().mockReturnValue(false),
+    toggleFavorite: vi.fn()
+  })
+}))
+
+vi.mock('@/services/dialogService', () => ({
+  useDialogService: () => ({
+    prompt: vi.fn()
+  })
+}))
+
+vi.mock('@/components/button/MoreButton.vue', () => ({
+  default: (_: unknown, { slots }: { slots: Slots }) =>
+    h('div', slots.default?.({ close: () => {} }))
+}))
+
+const i18n = createI18n({
+  legacy: false,
+  locale: 'en',
+  messages: {
+    en: {
+      g: {
+        rename: 'Rename',
+        enterNewName: 'Enter new name'
+      },
+      rightSidePanel: {
+        hideInput: 'Hide input',
+        showInput: 'Show input',
+        addFavorite: 'Favorite',
+        removeFavorite: 'Unfavorite',
+        resetToDefault: 'Reset to default'
+      }
+    }
+  }
+})
+
+describe('WidgetActions', () => {
+  beforeEach(() => {
+    setActivePinia(createTestingPinia({ stubActions: false }))
+    vi.resetAllMocks()
+    mockGetInputSpecForWidget.mockReturnValue({
+      type: 'INT',
+      default: 42
+    })
+  })
+
+  function createMockWidget(
+    value: number = 100,
+    callback?: () => void
+  ): IBaseWidget {
+    return {
+      name: 'test_widget',
+      type: 'number',
+      value,
+      label: 'Test Widget',
+      options: {},
+      y: 0,
+      callback
+    } as IBaseWidget
+  }
+
+  function createMockNode(): LGraphNode {
+    return {
+      id: 1,
+      type: 'TestNode'
+    } as LGraphNode
+  }
+
+  function mountWidgetActions(widget: IBaseWidget, node: LGraphNode) {
+    return mount(WidgetActions, {
+      props: {
+        widget,
+        node,
+        label: 'Test Widget'
+      },
+      global: {
+        plugins: [i18n]
+      }
+    })
+  }
+
+  it('shows reset button when widget has default value', () => {
+    const widget = createMockWidget()
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+    expect(resetButton).toBeDefined()
+  })
+
+  it('emits resetToDefault with default value when reset button clicked', async () => {
+    const widget = createMockWidget(100)
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+
+    await resetButton?.trigger('click')
+
+    expect(wrapper.emitted('resetToDefault')).toHaveLength(1)
+    expect(wrapper.emitted('resetToDefault')![0]).toEqual([42])
+  })
+
+  it('disables reset button when value equals default', () => {
+    const widget = createMockWidget(42)
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+
+    expect(resetButton?.attributes('disabled')).toBeDefined()
+  })
+
+  it('does not show reset button when no default value exists', () => {
+    mockGetInputSpecForWidget.mockReturnValue({
+      type: 'CUSTOM'
+    })
+
+    const widget = createMockWidget(100)
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+
+    expect(resetButton).toBeUndefined()
+  })
+
+  it('uses fallback default for INT type without explicit default', async () => {
+    mockGetInputSpecForWidget.mockReturnValue({
+      type: 'INT'
+    })
+
+    const widget = createMockWidget(100)
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+
+    await resetButton?.trigger('click')
+
+    expect(wrapper.emitted('resetToDefault')![0]).toEqual([0])
+  })
+
+  it('uses first option as default for combo without explicit default', async () => {
+    mockGetInputSpecForWidget.mockReturnValue({
+      type: 'COMBO',
+      options: ['option1', 'option2', 'option3']
+    })
+
+    const widget = createMockWidget(100)
+    const node = createMockNode()
+
+    const wrapper = mountWidgetActions(widget, node)
+
+    const resetButton = wrapper
+      .findAll('button')
+      .find((b) => b.text().includes('Reset'))
+
+    await resetButton?.trigger('click')
+
+    expect(wrapper.emitted('resetToDefault')![0]).toEqual(['option1'])
+  })
+})