feat: Private Tracker Style invites

See merge request !36

I also replaced magic-tree-mini with the full magic lib, as it's better.

I also updated all the crates.

oh yeah I added a robots.txt

I kinda started working on something else, then did another thing half way through
then I did another thing.

audron is a champion, a true hero.

This is mostly a test to see if I fixed git being REALLY slow at uploading over ssh

it even generates an nice error!