Make semaphore links work when logged out (+ include post details in previews)

[wlonkly]

Originally this feature request was going to be just for post details in previews, and I'd written:

If I link a semaphore.social post on Slack, I see:

Elk.zone previews the linked post instead:

Obviously the URL model is different, but for public posts it would be nice to not have to find the original link to a post vs. copying the semaphore.social link. (It would also help to promote semaphore.social!)

but I realize that that would also require links to public posts to display the posts, which would expand the scope of this feature request quite a bit... but it would be nice to be able to pass semaphore.social links around.

[NickColley]

You're right to make this happen you have to consider much wider changes. Unfortunately while it's clearly a great feature to have it's out of scope for this project, thank you for raising it though.