feat: unify search components by replacing SearchBox/SearchBoxV2 with SearchInput (#9644)

## Summary

Replace legacy `SearchBox` (PrimeVue) and `SearchBoxV2` with the unified
`SearchInput` (reka-ui) component across all consumers.

## Changes

- **What**: Remove `SearchBox.vue`, `SearchBoxV2.vue`, their tests and
stories. Migrate all 14 consumers to `SearchInput`. Move layout classes
to `ComboboxRoot` for proper flex sizing. Extract filter button/chips in
`NodeLibrarySidebarTab`. Standardize modal search width to `flex-1
max-w-lg`.
- **Dependencies**: None new — `SearchInput` already existed using
reka-ui

## Review Focus

- `NodeLibrarySidebarTab.vue`: filter button and `SearchFilterChip`
rendering moved outside the search component
- `SearchInput.vue`: `className` now applied to `ComboboxRoot` instead
of `ComboboxAnchor` for correct flex layout
- Modal dialogs (`WorkflowTemplateSelectorDialog`, `AssetBrowserModal`,
`SampleModelSelector`) unified to `flex-1 max-w-lg`

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9644-feat-unify-search-components-by-replacing-SearchBox-SearchBoxV2-with-SearchInput-31e6d73d365081ebac55cb265f33b631)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: github-actions <github-actions@github.com>

src/components/sidebar/tabs/ModelLibrarySidebarTab.vue

@@ -22,7 +22,7 @@
     </template>
     <template #header>
       <div class="px-2 2xl:px-4">
-        <SearchBox
+        <SearchInput
           ref="searchBoxRef"
           v-model:model-value="searchQuery"
           :placeholder="
@@ -56,7 +56,7 @@
 import { Divider } from 'primevue'
 import { computed, nextTick, onMounted, ref, toRef, watch } from 'vue'
 
-import SearchBox from '@/components/common/SearchBox.vue'
+import SearchInput from '@/components/ui/search-input/SearchInput.vue'
 import TreeExplorer from '@/components/common/TreeExplorer.vue'
 import SidebarTabTemplate from '@/components/sidebar/tabs/SidebarTabTemplate.vue'
 import ElectronDownloadItems from '@/components/sidebar/tabs/modelLibrary/ElectronDownloadItems.vue'