Revive browser mode test in `packages/ui`

[hi-ogawa]

Currently some tests are broken and CI is disabled. I partially recovered to dog-food aria snapshot in #9668 since the component and tests in packages/ui/client/components/artifacts/visual-regression are already well-scoped and seemed like a good fit.

I think packages/ui can be useful to dog-food browser mode, so probably we should make use of it. We also have test/ui for e2e but it would be nice if we can isolate per-component interaction logic properly, so they can be independently tested on browser mode.

Also enabling coverage might be also interesting.