port 2P step 1: vendor CPython 2.7.18 as the mtpython static library

The embedded 40250 script layer needs its own interpreter on five platforms.
2.7 is end-of-life, so nothing can be fetched from the target SDKs and the
source is vendored (official 2.7.18 tarball, trimmed to 25MB; Lib/ stays for
step 3's python27.zip).

cpython-2.7.18/CMakeLists.txt builds one `mtpython` static library from exactly
the 133 objects the reference libpython2.7.a contains, off by default behind
-DMTGODOT_EMBED_PYTHON=ON. The source list and the built-in module table
(config/config.c, 39 entries) are shared; pyconfig.h is a probe result and is
not, so each platform keeps its own under config/<platform>/, regenerated by
tools/py_embed/gen_pyconfig.sh and checked against the shared table.

Three vendor patches, documented in docs/THIRD-PARTY.md: configure/configure.ac
learn arm64 on macOS, and posixmodule.c undefines the process-control calls it
hard-defines past pyconfig.h when building for iOS.

macOS (ctest python.embed: every builtin imports, codecs and pickle work off the
vendored Lib/), Android arm64 and iOS arm64 build. Linux needs a Linux host and
Windows needs a MinGW-vs-MSVC decision; both are noted for step 4.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

audit/history.jsonl

@@ -492,3 +492,4 @@
 {"time":"2026-09-23T12:00:00Z","event":"port_round","unit":"platform UserInterface PackInitialize + EterBase/FileLoader.cpp + pack:// asset_io backend (PORT-PLAN §5 step 5b)","ported":["EterBase/FileLoader.cpp"],"deleted":[],"divergent":[],"needs_live":[],"status_note":"PackInitialize (platform, on-disk dbname resolution, no LogBoxf) + mtpack40250 backend + Metin2Pack node; no runtime reader uses pack:// until the proto/GDScript switch, so port-map statuses stay TODO","tests":["extension/tests/port_eterpack_test.cpp via PackSingletons+PackInitialize(\"pack\"): 103 packs, oracle order, PASS"],"commit":"5b"}
 {"time":"2026-09-23T12:30:00Z","event":"port_round","unit":"proto reader -> 40250 item_proto/mob_proto via CLZO + pack://locale/<lang>/ (PORT-PLAN §5 step 2 + step 5 runtime switch)","ported":["EterPack/EterPack.cpp (16 fns)","EterPack/EterPackManager.cpp (14)","EterPack/EterPackPolicy_CSHybridCrypt.cpp (1)","EterBase/lzo.cpp (11)","EterBase/tea.cpp (2)","EterBase/Stl.cpp (2)"],"adapted":["UserInterface/UserInterface.cpp PackInitialize","EterBase/FileLoader.cpp (5)","EterBase/MappedFile.cpp (9)","EterBase/FileBase.cpp (5)","EterBase/CRC32.cpp GetCRC32"],"deleted":["extension/src/proto/proto.cpp m2dev reader: XChaCha20 + MCOZ, 236-byte item / 335-byte mob strides"],"divergent":[],"needs_live":[],"status_note":"statuses set only for the functions a clang coverage run of proto_test + port_eterpack_test hit; the rest stay TODO. SMobTable is a local #pragma pack(1) mirror in proto.cpp (static_assert 255) until batch 2P ports GameLib/PythonNonPlayer. name = cp1252(szLocaleName) as CItemData::GetName / CPythonNonPlayer::GetMonsterName","tests":["extension/tests/proto_test.cpp: 5743 items / 1334 mobs from pack://locale/en PASS","extension/tests/proto_item_layout_test.cpp 156/255 strides, 236/335 rejected PASS","godot netbridge/equip_model/remote_player/mob_view PASS"],"commit":"2D-proto"}
 {"time":"2026-09-23T13:30:00Z","event":"asset_gate","unit":"PORT-PLAN §5 steps 3-4: MT_ASSETS_STRICT + provenance manifest + script/run_40250_asset_gate.sh","manifest":"audit/assets/40250-client.json (pack/Index + 214 .eix/.epk + 8 Eternexus/root/*.msm = 223 files, 1407474045 bytes, sha256)","env":{"MT_40250_CLIENT":"40250 Client dir (native tests, AssetRoot.client_path, gate)","MT_ASSETS":"m2dev loose dev override only","M2_ASSETS":"no longer used by tests"},"fixes":["remote_player_test accepted only twohand_sword/wait.msa; WAIT picks wait/wait_1 by weight, so it failed ~1/3 of runs"],"tests":["script/run_40250_asset_gate.sh macOS PASS (manifest, ctest port.eterpack|proto.*, godot netbridge/equip_model/remote_player/mob_view)","gate with MT_40250_CLIENT=/nonexistent exits 1"],"commit":"2D-gate"}
+{"time": "2026-09-23T15:30:00Z", "event": "third_party", "unit": "PORT-PLAN 批次 2P step 1: vendored CPython 2.7.18 as the mtpython static library", "source": "official Python-2.7.18.tgz sha256 b62c0e7937551d0cc02b8fd5cb0f544f9405bafc9a54d3808ed4594812edef43, trimmed to 25MB (Doc/Demo/Tools/Mac/PCbuild, Modules/{_ctypes,expat,zlib,_sqlite}, stdlib test trees, pre-VS2010 PC projects); Lib/ kept for step 3's python27.zip", "shared": "source list = the 133 objects of the reference libpython2.7.a; built-in table config/config.c = 39 entries (config/Setup.static)", "per_platform": "config/<plat>/pyconfig.h from tools/py_embed/gen_pyconfig.sh; android undefs HAVE_LANGINFO_H (nl_langinfo needs API 26); ios is derived from macos (2.7 configure refuses a darwin cross build) and drops process control + sys/random.h, keeping HAVE_GETGROUPS because posixmodule.c defines MAX_GROUPS only inside it", "patches": ["configure + configure.ac: arm64 MACOSX_DEFAULT_ARCH", "Modules/posixmodule.c: undef HAVE_SYSTEM/POPEN/FORK/EXECV/WAIT under TARGET_OS_IPHONE, which its own 'all other compilers' block hard-defines past pyconfig.h"], "not_done": ["Linux x86_64: gen_pyconfig.sh linux needs a Linux host", "Windows x64: upstream supports MSVC + PC/pyconfig.h while the Windows gate is MinGW, where PC/pyconfig.h leaves HAVE_UNISTD_H unset and posixmodule.c/dynload_win.c collide with the MinGW headers; decided in step 4"], "ported": [], "deleted": [], "divergent": [], "needs_live": [], "status_note": "no port-map entry: this is third-party source, not a ported 40250 unit. Linking into libmtgodot is step 2 (ScriptLib/PythonLauncher.cpp)", "tests": ["ctest python.embed (macOS arm64): 39 builtin modules, all import, sys.version 2.7.18, utf-8/cp1252 codecs + pickle round-trip via the vendored Lib/ PASS", "android arm64 NDK API 24: libmtpython.a builds clean", "ios arm64 iphoneos: libmtpython.a = 133 objects, no undefined _system/_fork/_popen"], "commit": "2P-step1"}