Login rules

With ServerQueueGameSession (or your own game session calling CaptureLoginOptions), the game server checks every login:

Player	Result
Holds a reservation and presents its token	Let in
Holds a reservation, wrong or missing token	Refused
In their grace period (with or without token)	Let in
No slot, a slot is free for them and Allow Direct Join is on	Let in
No slot otherwise	Refused: "ServerQueue: the server is full. Join through the queue."

A reservation lasts Reservation Timeout (30 s). A player who leaves the game keeps their slot for Reconnect Grace Period (120 s, 0 turns it off), so they can come back without queueing.