feat: add dynamic Fuse.js options loading for template filtering (#7822)

## Summary

PRD:
https://www.notion.so/comfy-org/Implement-Move-search-config-to-templates-repo-for-template-owner-adjustability-2c76d73d365081ad81c4ed33332eda09

Move search config to templates repo for template owner adjustability

## Changes

- **What**: 
- Made `fuseOptions` reactive in `useTemplateFiltering` composable to
support dynamic updates
- Added `getFuseOptions()` API method to fetch Fuse.js configuration
from `/templates/fuse_options.json`
- Added `loadFuseOptions()` function to `useTemplateFiltering` that
fetches and applies server-provided options
- Removed unused `templateFuse` computed property from
`workflowTemplatesStore`
- Added comprehensive unit tests covering success, null response, error
handling, and Fuse instance recreation scenarios

- **Breaking**: None

- **Dependencies**: None (uses existing `fuse.js` and `axios`
dependencies)

## Review Focus

- Verify that the API endpoint path `/templates/fuse_options.json` is
correct and accessible
- Confirm that the reactive `fuseOptions` properly triggers Fuse
instance recreation when updated
- Check that error handling gracefully falls back to default options
when server fetch fails
- Ensure the watch on `fuseOptions` is necessary or can be removed
(currently just recreates Fuse via computed)
- Review test coverage to ensure all edge cases are handled

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7822-feat-add-dynamic-Fuse-js-options-loading-for-template-filtering-2db6d73d365081828103d8ee70844b2e)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>

src/components/custom/widget/WorkflowTemplateSelectorDialog.vue

@@ -563,7 +563,8 @@ const {
   availableRunsOn,
   filteredCount,
   totalCount,
-  resetFilters
+  resetFilters,
+  loadFuseOptions
 } = useTemplateFiltering(navigationFilteredTemplates)
 
 /**
@@ -815,10 +816,10 @@ const pageTitle = computed(() => {
 // Initialize templates loading with useAsyncState
 const { isLoading } = useAsyncState(
   async () => {
-    // Run all operations in parallel for better performance
     await Promise.all([
       loadTemplates(),
-      workflowTemplatesStore.loadWorkflowTemplates()
+      workflowTemplatesStore.loadWorkflowTemplates(),
+      loadFuseOptions()
     ])
     return true
   },