fix: autofocus filter input in Select dropdowns to prevent shortcut triggers (#7253)

## Summary
- Adds `auto-filter-focus` prop to Select component when filtering is
enabled
- When the dropdown opens, the filter input is automatically focused
- This prevents keystrokes from triggering global shortcuts while the
user is trying to filter options

## Root Cause
When a user opens a Select dropdown with a filter and starts typing
without explicitly clicking the search box, the filter input doesn't
have focus. Keystrokes are then captured by global shortcut handlers
(e.g., pressing "R" triggers "refresh nodes") instead of filtering the
options.

## Solution
PrimeVue's Select component has an `auto-filter-focus` prop that
automatically focuses the filter input when the dropdown opens. By
enabling this whenever filtering is enabled (`selectOptions.length >
4`), users can immediately start typing to filter without needing to
click the search box first.

## Test plan
- [ ] Open a Select dropdown with more than 4 options (e.g., Load
Checkpoint's ckpt_name)
- [ ] Verify the filter input is automatically focused when the dropdown
opens
- [ ] Type a character and verify it filters the list instead of
triggering shortcuts
- [ ] Verify no console errors when opening/closing the dropdown

Fixes #7221

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7253-fix-autofocus-filter-input-in-Select-dropdowns-to-prevent-shortcut-triggers-2c46d73d365081feacd1f3301aa3b413)
by [Unito](https://www.unito.io)

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

@@ -4,6 +4,7 @@
       v-model="modelValue"
       :invalid
       :filter="selectOptions.length > 4"
+      :auto-filter-focus="selectOptions.length > 4"
       :options="selectOptions"
       v-bind="combinedProps"
       :class="cn(WidgetInputBaseClass, 'w-full text-xs')"