While starting on the create workspace flow - I noticed some weird CSS issues.
In particular, intermittently, the web UI would render like this:

...and when that happened, there'd be an accompanying error in the console:

The issue is that NextJS is trying to render the page on the server and use the styles - and sometimes the classnames mismatch between server-side and client-side rendering. We actually worked around this in `cdr/m` with a `<SafeHydration />` component and a custom `_document.tsx`
This change ports over both the component and custom `_document.tsx`. I noticed, in addition, I missed the favicons when switching to NextJS, so I brought those over too.