On server, replace arenas with saved game configs
- Each saved game config stores duration, map, game type etc.
- Server has a flag about whether to enable a lobby where people can suggest game types.
- Have a server setting listing available game ports to use. Each game/lobby just uses the next available port
- Games can be started either from the lobby, or by admins from the server web interface.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information