Auto-download larger models

[ambitious-octopus]

Our collection of corelm models is expanding, and we need an automated system to download them efficiently. We can integrate smaller models, such as n/s (and possibly m, if it isn't too large), directly into the app. For larger models, we can implement a just-in-time download system to provide them as needed by the user. What do you think @john-rocky?

[john-rocky]

@ambitious-octopus
I can create a system to download large models while the app is in use (or at the user's option).