Player controlled "retirement/snooze"

Retirement of a player is indicated on the "Game Details" page (maybe a label "Retired" next to the player's name?) and sends a notification to the GM, so they know the player has retired. If they need to get the players attention they now know they will need to @ mention or Message the player in the future. This will help avoid retirement by accident.

Retirement is reversible, so you can "un-retire" later if you need to, or if you did it by accident.