Registers queue:join/queue:leave handlers that FIFO-pair waiting players,
randomly assign timeMode (1 or 2, uniform) and theme via themeIds.js, and
hand off to game/session.js's createSession. Tracks a 2-minute
matchmaking-only quit ban (in-memory, resets on restart) via onEnd's
'quit' reason, scoped to sessions this module produced. Exports
isBanned() and registerMatchmakingHandlers(), wired into index.js at
boot.
Also extends ws/registry.js with a playerId -> display name store
(registerSocket's new optional third arg, getPlayerName()) so
match:found.opponentName (and future room:joined.opponentName) can be
populated; connectionHandler.js's identify handler now passes name
through.
