if observe-only doesn't do any ui ever, don't open the example tab.

[gregglind]

(Confirm that existing code works like this)

[casebenton]

This won't happen, as the observe-only branch never creates a Recommender instance and calls Rec.start(). Onboarding event, which opens example tab, is called in Rec.start() method.

const variations = {
  'passive-panel'() {
    Rec = new Recommender();
    Rec.start();
  },
  'auto-open-panel'() {
    simplePrefs.prefs.autoOpenPanel = true;
    Rec = new Recommender();
    Rec.start();
  },
  'observe-only'() {},
};