V2 Node Search (+ hidden Node Library changes) (#8987)

## Summary

Redesigned node search with categories

## Changes

- **What**: Adds a v2 search component, leaving the existing
implementation untouched
- It also brings onboard the incomplete node library & preview changes,
disabled and behind a hidden setting
- **Breaking**: Changes the 'default' value of the node search setting
to v2, adding v1 (legacy) as an option

## Screenshots (if applicable)




https://github.com/user-attachments/assets/2ab797df-58f0-48e8-8b20-2a1809e3735f

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8987-V2-Node-Search-hidden-Node-Library-changes-30c6d73d36508160902bcb92553f147c)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Yourz <crazilou@vip.qq.com>
Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: github-actions <github-actions@github.com>
Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Christian Byrne <cbyrne@comfy.org>

src/components/common/SearchBoxV2.test.ts

@@ -0,0 +1,90 @@
+import { mount } from '@vue/test-utils'
+import { describe, expect, it, vi } from 'vitest'
+import { createI18n } from 'vue-i18n'
+
+import SearchBoxV2 from './SearchBoxV2.vue'
+
+vi.mock('@vueuse/core', () => ({
+  watchDebounced: vi.fn(() => vi.fn())
+}))
+
+describe('SearchBoxV2', () => {
+  const i18n = createI18n({
+    legacy: false,
+    locale: 'en',
+    messages: {
+      en: {
+        g: {
+          clear: 'Clear',
+          searchPlaceholder: 'Search...'
+        }
+      }
+    }
+  })
+
+  function mountComponent(props = {}) {
+    return mount(SearchBoxV2, {
+      global: {
+        plugins: [i18n],
+        stubs: {
+          ComboboxRoot: {
+            template: '<div><slot /></div>'
+          },
+          ComboboxAnchor: {
+            template: '<div><slot /></div>'
+          },
+          ComboboxInput: {
+            template:
+              '<input :placeholder="placeholder" :value="modelValue" @input="$emit(\'update:modelValue\', $event.target.value)" />',
+            props: ['placeholder', 'modelValue', 'autoFocus']
+          }
+        }
+      },
+      props: {
+        modelValue: '',
+        ...props
+      }
+    })
+  }
+
+  it('uses i18n placeholder when no placeholder prop provided', () => {
+    const wrapper = mountComponent()
+    const input = wrapper.find('input')
+    expect(input.attributes('placeholder')).toBe('Search...')
+  })
+
+  it('uses custom placeholder when provided', () => {
+    const wrapper = mountComponent({
+      placeholder: 'Custom placeholder'
+    })
+    const input = wrapper.find('input')
+    expect(input.attributes('placeholder')).toBe('Custom placeholder')
+  })
+
+  it('shows search icon when search term is empty', () => {
+    const wrapper = mountComponent({ modelValue: '' })
+    expect(wrapper.find('i.icon-\\[lucide--search\\]').exists()).toBe(true)
+  })
+
+  it('shows clear button when search term is not empty', () => {
+    const wrapper = mountComponent({ modelValue: 'test' })
+    expect(wrapper.find('button').exists()).toBe(true)
+  })
+
+  it('clears search term when clear button is clicked', async () => {
+    const wrapper = mountComponent({ modelValue: 'test' })
+    const clearButton = wrapper.find('button')
+    await clearButton.trigger('click')
+    expect(wrapper.emitted('update:modelValue')?.[0]).toEqual([''])
+  })
+
+  it('applies large size classes when size is lg', () => {
+    const wrapper = mountComponent({ size: 'lg' })
+    expect(wrapper.html()).toContain('size-5')
+  })
+
+  it('applies medium size classes when size is md', () => {
+    const wrapper = mountComponent({ size: 'md' })
+    expect(wrapper.html()).toContain('size-4')
+  })
+})