feat(windows): replace php-sdk-binary-tools with MSYS2 + 7za-win

- Add msys2-build-essentials target: downloads the MSYS2 nightly sfx,
  extracts it, disables PGP keyring (CI-safe), runs two-pass pacman
  update, and installs autotools build essentials (make, autoconf,
  automake, libtool, pkgconf, perl).
- Add 7za-win target: downloads 7za.exe to PKG_ROOT_PATH\bin.
- Remove php-sdk-binary-tools target and all PHP_SDK_PATH references;
  replace with SPC_MSYS2_PATH throughout Artifact, ArtifactExtractor,
  FileSystem, DefaultShell and MSVCToolchain.
- Replace {php_sdk_path} path placeholder with {spc_msys2_path}.
- WindowsToolCheck: replace checkSDK/installSDK with checkMsys2,
  installMsys2 and check7zaWin/install7zaWin fix items.
- nasm.yml: extract nasm.exe/ndisasm.exe to {pkg_root_path}/bin.
- env.ini: rename PHP_SDK_PATH to SPC_MSYS2_PATH.
- Docs: update Windows migration guide and package-model placeholder docs.

docs/en/develop/package-model.md

@@ -229,7 +229,7 @@ The following path placeholders are supported in string values of the `path`, `e
 | `{working_dir}` | Working directory (project root) |
 | `{download_path}` | Download cache directory (`downloads/`) |
 | `{source_path}` | Extracted source directory (`source/`) |
-| `{php_sdk_path}` | Windows PHP SDK directory |
+| `{spc_msys2_path}` | MSYS2 root directory (`msys64/`) — Windows only |
 
 ## target Package Type
 

docs/en/guide/migrate-from-v2.md

@@ -58,7 +58,13 @@ A single-file hook API for lightweight patches may be provided in a future relea
 
 ### Windows-only: `--with-sdk-binary-dir` and `--vs-ver`
 
-These options are no longer accepted on the command line. Instead, set the `PHP_SDK_PATH` environment variable to point to your PHP SDK binary tools directory. The Visual Studio version is now managed by the toolchain configuration.
+These options are no longer accepted on the command line. In v3, the `php-sdk-binary-tools` dependency has been completely removed. v3 now manages its own **MSYS2** environment to support autotools-based library builds on Windows. Run `spc doctor --install` to download and configure MSYS2 automatically.
+
+If you need to point to a custom MSYS2 installation, set the `SPC_MSYS2_PATH` environment variable to the `msys64` directory (e.g. `C:\msys64`). Visual Studio is now auto-detected by the toolchain — no manual version flag needed.
+
+::: warning Migrating from v2
+v2 relied on `php-sdk-binary-tools` and required `--with-sdk-binary-dir` and `--vs-ver` on every build invocation. In v3 these options are gone. Remove them from all CI scripts and run `spc doctor --install` once to set up the Windows build environment.
+:::
 
 ## Renamed / Deprecated Options
 

docs/zh/develop/package-model.md

@@ -223,7 +223,7 @@ openssl:
 | `{working_dir}` | 工作目录（项目根目录） |
 | `{download_path}` | 下载缓存目录（`downloads/`） |
 | `{source_path}` | 解压源码目录（`source/`） |
-| `{php_sdk_path}` | Windows PHP SDK 目录 |
+| `{spc_msys2_path}` | MSYS2 根目录（`msys64/`）——仅 Windows |
 
 ## target 包类型
 

docs/zh/guide/migrate-from-v2.md

@@ -58,7 +58,13 @@ curl -o spc https://dl.static-php.dev/v3/spc-bin/nightly/spc-linux-x86_64
 
 ### Windows 专有：`--with-sdk-binary-dir` 和 `--vs-ver`
 
-这两个选项已不再被命令行接受。请改为设置 `PHP_SDK_PATH` 环境变量，指向你的 PHP SDK binary tools 目录。Visual Studio 版本现在由工具链配置统一管理。
+这两个选项已不再被命令行接受。在 v3 中，`php-sdk-binary-tools` 依赖已被完全移除。v3 现在通过管理自己的 **MSYS2** 环境来支持 Windows 上基于 autotools 的库构建。运行 `spc doctor --install` 即可自动下载并配置 MSYS2。
+
+如需指向自定义 MSYS2 安装目录，请设置 `SPC_MSYS2_PATH` 环境变量，值为 `msys64` 目录路径（例如 `C:\msys64`）。Visual Studio 版本现在由工具链自动检测，无需手动指定版本号。
+
+::: warning 从 v2 迁移
+v2 依赖 `php-sdk-binary-tools`，并在每次构建时需要传入 `--with-sdk-binary-dir` 和 `--vs-ver` 参数。在 v3 中这些选项已被移除。请从所有 CI 脚本中删除这些参数，并使用 `spc doctor --install` 一次性完成 Windows 构建环境的配置。
+:::
 
 ## 已重命名 / 已弃用的选项