Unborn user not redirected upon interact

[ryanlovett]

If a user visits an interact link before they have ever logged in, they are sent to the regular hub landing page. I think the fix for this is to change the default landing page to /user-redirect/. This has the side effect of starting up a user's server automatically after authenticating.

I don't know if the query params get passed all of the way through from first visit through user creation to user-redirect (to notebook).

[ryanlovett]

We discovered that the query params are getting lost during OAuth. @yuvipanda suggested setting a cookie with the query params before OAuth, then looking for them afterwards.