2V1-b/c: PythonNetworkStream phases, AccountConnector and the net module

Port PythonNetworkStream with its HandShake/Login/Select/Loading/Offline
phases, AccountConnector and PythonNetworkStreamModule verbatim; the net
stub goes. PythonBoot creates the network stream, account connector,
player, flying manager and effect manager like CPythonApplication, and
app.Create/Process drive CNetworkDevice and both connectors.

Packet.h long fields become 32-bit LONG; port.packet checks 38
login/select/loading packet sizes against wire_classic.h. Unported units
in the link closure live under platform/pending/ as stand-ins. The macOS
gate now builds all and finds iconv.

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

extension/src/platform/pending/UserInterface/PythonGuild.cpp

@@ -0,0 +1,13 @@
+// Stand-in for the 40250 unit UserInterface/PythonGuild.cpp, not ported yet: the CPythonGuild member the ported
+// net module (批次 2V1) references, as an MT_PLATFORM_STUB(). Delete this file in the commit that ports the unit
+// into port/ (docs/PORT-PLAN.md 2V1).
+#include "UserInterface/StdAfx.h"
+#include "UserInterface/PythonGuild.h"
+
+#include "../../PlatformStub.h"
+
+BOOL CPythonGuild::GetMemberDataPtrByName(const char *, TGuildMemberData **)
+{
+	MT_PLATFORM_STUB();
+	return FALSE;
+}