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/port/UserInterface/PythonPackModule.cpp

@@ -6,10 +6,6 @@
 DWORD g_adwEncryptKey[4];
 DWORD g_adwDecryptKey[4];
 
-// PORT: the login cipher's key builder happens to live in this unit, but it is CAccountConnector's —
-// AccountConnector.h and the class come with the login slice (docs/PORT-PLAN.md 批次 2V1). Kept verbatim
-// and compiled out until then; the two keys above stay, they are what the network stream reads.
-#if 0
 #include "AccountConnector.h"
 
 inline const BYTE* GetKey_20050304Myevan()
@@ -40,7 +36,6 @@ void CAccountConnector::__BuildClientKey_20050304Myevan()
 	tea_encrypt((DWORD *) g_adwDecryptKey, (const DWORD *) g_adwEncryptKey, (const DWORD *) (c_pszKey+37), 16);
 //	TEA_Encrypt((DWORD *) g_adwDecryptKey, (const DWORD *) g_adwEncryptKey, (const DWORD *) (c_pszKey+37), 16);
 }
-#endif
 // END_OF_CHINA_CRYPT_KEY
 
 PyObject * packExist(PyObject * poSelf, PyObject * poArgs)