Currently tangled quietly expects ssh-keys to be unique to each users. Which leads to some unexpected "access denied" on git push like reported on discord.

We can solve this in two ways.

1. appview side fix: force user to set unique ssh-key on register#

Basically telling user "your ssh-key is already used by @otheruser.com"

2. knot side fix: check for all existing users with same ssh-key#

Allow users to share same ssh-key between multiple accounts and warn when authority collides.

access denied for user @otheruser.com

same ssh-key is used by @you.com who has access to this repository.
Please set unique ssh-key for each accounts.