Removal of internal/files API breaks 3rd party tools such as GIMP plugins

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

the internal/files endpoint is accessible as it is an essential tool for 3rd party frontends for comyui

### Actual Behavior

the internal/files endpoint returns a 404 error

### Steps to Reproduce

Attempt to use a 3rd party frontend tool for comfyui such as this gimp plugin: https://github.com/Charlweed/gimp_comfyui?tab=readme-ov-file

### Debug Logs

```powershell
[cui_resources_utils.py:229 - request_resource_catalog() ] url=http://localhost:8188/internal/files?directory=models, code=404, reason=Not Found
```

### Other

I've been trying to connect ComfyUI to GIMP and it appears one of the API endpoints the plugin relied on was removed because its not used by ComfyUI itself: https://github.com/comfyanonymous/ComfyUI/pull/6714

It seems to me that this endpoint was intended to be a service for 3rd party tools and it may have been removed by accident.