port 2V2-b: GamePhase dispatch consumes the Entergame burst

PythonNetworkStreamPhaseGame/PhaseGameActor/PhaseGameItem/Command,
NetworkActorManager and PythonChat/PythonChatModule are ported verbatim and
dispatched at runtime; the 2V0 chat stub module is removed and initChat()
runs before initnet() as in 40250. InstanceBase, PythonCharacterManager and
GameLib ActorInstance/RaceData/RaceManager compile but stay TODO until
2V2-c/d wire them.

Units not ported yet get their singletons from PythonBoot's GameSingletons
(CPythonApplication member order) and platform/pending stand-ins generated
by platform_stub.py pending; const char* stand-ins return "".

port.login_flow's fake server now sends the CInputLogin::Entergame order
(actor insert, NPC positions, PHASE_GAME, land list, time, channel, greet
notice, ping) and a TraceError observer asserts no unknown packet header.
port.login_live passes against the real server for 10 s of game phase.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

extension/src/platform/PlatformStub.h

@@ -35,6 +35,12 @@ T mt_platform_stub_return()
 			return static_cast<T>(*reinterpret_cast<U*>(storage));
 		}
 	}
+	else if constexpr (std::is_same_v<T, const char*>)
+	{
+		// Callers strcmp/strlen/format the names these return (CPythonPlayer::GetName in RecvGuild); a
+		// null string would crash where the real function never returns one.
+		return "";
+	}
 	else if constexpr (std::is_default_constructible_v<T>)
 	{
 		return T{};