Right now you can't change sitename from Admin Panel if try you break Aiki. and solution is not documented you need to run a sql query. If you have one site then:
UPDATE aiki_sites SET site_name = '<Your site name>';
I can add translate to site_name in Aiki.
I can add functionality to change site name to Admin Panel but current panel is a mess, I think that will be better to fix it in new Panel. I wanted to start working on it ASAP.