feat: add model updates check to global context menu

Add a new "Check Model Updates" option to the global context menu that allows users to manually check for model updates. This includes:

- Adding refreshUpdates endpoint to API configuration
- Implementing checkModelUpdates method with proper loading states
- Adding internationalization support for update messages
- Handling success/error states with appropriate user feedback
- Automatically reloading models after update check completes

The feature provides users with manual control over update checks and improves visibility into model update availability.

static/js/api/apiConfig.js

@@ -76,6 +76,7 @@ export function getApiEndpoints(modelType) {
         fetchAllCivitai: `/api/lm/${modelType}/fetch-all-civitai`,
         relinkCivitai: `/api/lm/${modelType}/relink-civitai`,
         civitaiVersions: `/api/lm/${modelType}/civitai/versions`,
+        refreshUpdates: `/api/lm/${modelType}/updates/refresh`,
         
         // Preview management
         replacePreview: `/api/lm/${modelType}/replace-preview`,