preserve selected model list when viewing a permalink

[zeke]

When you share a link, the list of active models you used should be models that are shown when someone else visits the link.

Repro

1. Choose a custom set of models by flipping some checkboxes
2. Run a prediction
3. Copy the URL
4. Paste the URL in a new tab
5. The selected models are not displayed. :[

[zeke]

This actually also breaks between page views and refreshes:

1. Go to a page
2. Pick some models
3. Run a prediction
4. Refresh the page
5. Differently models now picked