Filter workflows to show only those with locally downloaded models

### Feature Idea

Add a button, toggle, or filter option in the user interface that hides workflows requiring missing models. It should only display workflows where all necessary models are already present in the local storage

### Existing Solutions

Manually checking each workflow or opening them one by one to see if they load without errors, which is time consuming

### Other

This feature would significantly improve the user experience for offline usage and quick testing of existing setups. Thank you for your time and great work on ComfyUI!

The issue points to the workflow list UI and local storage of models; start by tracing how workflows are loaded and how missing models are detected. Done means a user-facing filter or toggle hides workflows with any missing model while retaining workflows whose required models are present for offline use.

Written by the indexing model from the issue text.