TPG.Rounds.BeginInitialWait

Hold the first round of a map until players have finished loading in. Fast loaders used to join, take a team, and start burning the team budget (or earning economy income) while slow loaders were still on the loading screen. This waits TPG.Config.waitBaseTime as a floor, pushes the start waitJoinExtend further out whenever someone is mid-connect, and gives up at waitMaxTotal so one stuck client cannot hold the server hostage. A connection that goes quiet is forgotten after three minutes. While it runs, TPG.State.waitingForPlayers is true and building is blocked (sv_duplication and the PlayerSpawnProp check read that flag). Setup force-clears it, so no path can leave building blocked. Called once from GM:Initialize. It ends by calling Setup itself.