I had experimented with turning this off in order to improve test performance, and apparently that ended up being merged. Now if we're to do component testing, we'll be changing things globally on the document, so isolation is very much necessary.

This patch release fixes a bug where tooltips would label non-interactive triggers in an inaccessible way.

Catching two accessibility issues along the way: we were putting the wrong accessible labels on the 'expand' button, and even the off-screen pages of the spotlight tile were being exposed to accessibility technologies rather than hidden.

This adds tests for a couple of the less trivial bits of code in CallViewModel. Testing them helped me uncover why focus switches still weren't being smooth! (It was because I was using RxJS's sample operator when I really wanted withLatestFrom.)