port(2P step 3a/3b): stdlib on sys.path + the pack module

step 3a — 标准库:
  tools/py_embed/make_stdlib_zip.py packs the vendored Lib/ into
  <build>/python27.zip (397 modules, 6876547 bytes, ZIP_STORED — the zlib
  module is trimmed out of our CPython, so zipimport cannot inflate).
  The mtpython_stdlib target builds it; py_embed_test and the launcher test
  both run against it.
  platform/ScriptLib/PythonHost sets the embedding flags before
  Py_Initialize and, after it, puts the zip on sys.path and re-registers
  encodings.search_function with codecs — 2.7 builds the codec registry
  once, at startup, so replacing sys.path afterwards needs it back.

step 3b — pack 模块:
  UserInterface/PythonPackModule.cpp copied verbatim; packExist/packGet/
  initpack read root/ and uiscript/ through CEterPackManager, i.e. through
  asset_io. The CHINA_CRYPT_KEY block in that unit is CAccountConnector's
  and is kept #if 0 until the login slice (2V1). UserInterface/StdAfx.h is
  a documented partial mirror — the original is the whole client's PCH.

The launcher test now runs initpack() as RunMainScript does (its first
line), reads system.py / uiscript / locale text back out of the packs, and
confirms cp1252 decoding works off the zip. system.py still stops at
"No module named app" — the C++ modules are the 2V0 slice.

gates: port_map.py check 0 errors · key leak check 8/8 none · macOS ctest
27/27 · android + ios port_platform compile clean.

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

docs/PORT-PLAN.md

@@ -82,7 +82,7 @@ extension/third_party/cpython-2.7.18/                  # 静态库（2P 批次
 | — | 定下目录结构，评估内嵌 Python；Android 独立程序验证 | 完成（9d0e50de、b02c49bb） |
 | **2A** | 基础：Win32 类型层、参考公共头的最小闭包、`port_logic` CMake 目标、platform 接口骨架、头文件可编译门禁、port-map 重新基线 | **进行中**（剩 Python 库闭包头，等 2P） |
 | 2R | 资源包能力盘点：EPK 类型/密钥/覆盖顺序/路径大小写/移动端交付 | 完成：只有 NONE/COMPRESS/SECURITY，不需要服务器密钥；设备上直接读 EPK |
-| **2P** | CPython 2.7.18 编进 libmtgodot，五个平台分别配置和验证 | **进行中**：step 1（静态库 + macOS/Android/iOS 配置）、step 2（ScriptLib 进 `port_logic`）完成 |
+| **2P** | CPython 2.7.18 编进 libmtgodot，五个平台分别配置和验证 | **进行中**：step 1（静态库 + macOS/Android/iOS 配置）、step 2（ScriptLib 进 `port_logic`）、step 3a/3b（python27.zip + `PythonHost` + `pack` 模块）完成 |
 | 2D | 数据源切到 40250（msm 路径、proto、资源根、严格资源测试） | 完成（5a26e93f、232d0461、240d2827、a9b31dec）；资源根只切了 proto/pack 后端，其余按第 5 节由 2V 切片逐个切换 |
 | **2V0** | UI 壳：真实 `PythonLauncher/wndMgr/grp/app` + platform UI，其他玩法模块用桩，显示并操作 Logo/Popup | 需要 2A、2P 和 root/uiscript 子集 |
 | **2V1** | 登录/选角：真实 `net` phase、登录/选角脚本及所需模块，走到 Loading | 2V0 之后 |
@@ -299,6 +299,21 @@ extension/third_party/cpython-2.7.18/                  # 静态库（2P 批次
    - Android/iOS 首次启动从应用资源复制到应用沙盒，校验提交在资源清单中的 sha256，再加入 `sys.path`；
    - `zipimport` 静态编进解释器。`system.py` 的导入钩子只负责 pack 内的简单 root 模块，不能用来加载标准库 package、
      dotted import 或 `encodings`。
+
+   **已完成（3a 标准库 + 3b pack 模块）**：`tools/py_embed/make_stdlib_zip.py` 把 vendored `Lib/` 打成
+   `<build>/python27.zip`（397 个模块 / 6.9MB，全部 STORED——没有 zlib 模块，zipimport 解不了 deflate；
+   内容确定性写入，sha256 就是 3c 的校验值），CMake 目标 `mtpython_stdlib` 跟着 `Lib/*.py` 重建。
+   宿主引导收进 `extension/src/platform/ScriptLib/PythonHost.{h,cpp}`：`Configure()` 设四个标志和程序名，
+   `InstallStdLib()` 在 `Py_Initialize` 之后换掉 `sys.path` 并重新 `codecs.register(encodings.search_function)`
+   （2.7 的 codec 注册表只在启动时初始化一次）。`python.embed` 现在直接跑 zip。
+   `UserInterface/PythonPackModule.cpp` 已移植（`packExist`/`packGet`/`initpack`），经 `CEterPackManager`
+   读 pack，即 `asset_io` 的 `pack://` 用的同一套；`port.python_launcher` 验证 `pack.Get` 取到的
+   `system.py` 与 `CEterPackManager` 的字节数一致，并能读 `uiscript/selectcharacterwindow.py`、
+   `locale/en/locale_game.txt`，非 `.py/.pyc/.txt` 和不存在的文件返回 `None`。
+   `UserInterface/StdAfx.h` 只镜像了当前能编的部分（原文件 include 整个客户端和 DirectShow），
+   `PythonPackModule.cpp` 里属于 `CAccountConnector` 的登录密钥函数原样保留但编译时排除，随 2V1 回来。
+   **未完成（3c）**：Android/iOS 从应用资源把 zip 复制进沙盒并校验 sha256；`PythonHost::DefaultStdLibPath()`
+   现在只认 `MT_PYTHON_STDLIB`。
 4. 五个平台分别验证：编译、链接无未定义符号、`Py_Initialize`、静态 C 模块逐个 `import`、在 app 进程里跑 `system.py` → `prototype.RunApp()`（对照结果：74 个模块中 66 个加载成功，引导期调用 33 个 C++ 函数）。
 
    | 平台 | 状态 |

docs/THIRD-PARTY.md

@@ -100,8 +100,11 @@ one via a 1-line shim header, see below).
   `Python-2.7.18.tgz` (sha256 `b62c0e7937551d0cc02b8fd5cb0f544f9405bafc9a54d3808ed4594812edef43`)
   trimmed of what an embedded interpreter never builds or ships: `Doc Demo Tools
   Mac PCbuild`, `Modules/{_ctypes,expat,zlib,_sqlite}`, the stdlib test trees and
-  the pre-VS2010 `PC/` project files. `Lib/` stays — batch 2P step 3 ships it as
-  `python27.zip`.
+  the pre-VS2010 `PC/` project files. `Lib/` stays: the `mtpython_stdlib` target
+  packs it into `<build>/python27.zip` with `tools/py_embed/make_stdlib_zip.py`,
+  which is what the host puts on `sys.path` (batch 2P step 3). Entries are
+  **stored, never deflated** — the `zlib` module is trimmed out above, so
+  `zipimport` has nothing to inflate with.
 * **Why vendored:** 2.7 is end-of-life, so there is no package to fetch on the
   four target SDKs, and the build must keep working offline and on the
   cross-build machines. It is the version the 40250 scripts are written for