Lobby Game End Cleanup (WIP)

[CDMayberry]

Did some investigation into possible memory leaks. Two things that came up were:

1. a possible failure to cleanup Game from the Lobby.
2. No cleanup process when a Game is ended.

This adds some fixes to Lobby as well as some new cleanup code to ensure data like the snapshots and the main allGameObjects list are cleared. I'm not positive this is the culprit of the memory leak but cleaning up the snapshots and explicitly clearing a bunch of the data is probably still a good call.

Changes

Added explicit teardown via Game.destroy(), SnapshotManager.destroy(), and GameStateManager.destroy(), wired listener-owning subsystems into cleanup (OngoingEffectEngine, GameStatisticsLogger), and updated Lobby so only active unfinished games count as ongoing. Permanently finished Bo1 / completed Bo3 games are now destroyed and released; the short between-games Bo3 case is still retained until transition. I also fixed removeUser() so it doesn’t try to send game state after cleanup.

Added tests in test\server\core\GameStateManagerDestroy.spec.ts and test\server\gamenode\Lobby.spec.ts.