Roster confirmation: the leader approves each sign-up

Signing up is now a two-step process: a member indicates they'll be there, and the group leader approves the sign-up. Instead of a name list typed by hand into the description, a structured roster everyone can see becomes the source of “who is serving”.

You can see the approved names during the event and on the home-page card too – “Serving today: …” – and the rostered member gets a notification about it in their own language. On a compact panel the admin approves sign-ups with one click, and can revoke them at any time.