Thread & forks redesign

Phase: Upcoming

We want to redesign threads, comments in thread, forks, and the thread card on the feed, to address several problems:

Opening a subthread as a new Thread screen loses some context and surrounding comments from the top-most thread
Too easy to miss a reply somewhere in a subthread or in a subsubthread
On the other hand, if forks are too easy to create, they encourage tangents and make the conversation harder to navigate, while discouraging comments that would end up in the "wrong branch" which may cause negative feelings to new comers
Too much nesting can be hard to navigate for new comers
There may not exist a threading UI that is universally loved
Some people "fork" a thread in an entirely manual way, e.g. just with cypherlinks
Comments counter in Thread screen can be confusing: #1771
When the user clicks a ThreadCard on the feed, the affordance may be confusing (click the link in the faded preview or click the whole card?), see (outdated) issue #1803