docs(readme): M143 下载表把 windows-arm64 标为暂未发布

依据 `.github/workflows/release.yml:291` 的 `PUBLISH_SLOTS: "windows-x64"`：arm64 槽位仍在
矩阵里构建取证，但不进 Release（同文件 300-313 行还会把白名单外的产物裁掉）。用户照旧表去下
`..._windows_arm64.exe` 会 404。

- 两版 README 的 Shape 列加「暂未发布 / not yet published」，行不删（架构支持意图仍在）
- 表后补一段可核的理由：CI 的 ARM64 runner 缺 Windows SDK 的 ARM64 导入库，已定位、在修；
  并点明 PUBLISH_SLOTS 才是「进不进 Release」的开关，windows-x64 是当前唯一可下载的 Windows 资产
- 不写日期/版本承诺；windows-x64 命名规则与体量描述未动；packaging/README.md 与
  release-notes.md 未碰

README.md

@@ -205,7 +205,7 @@ Grab the file for your platform from
 | Slot | Asset | Shape |
 |------|-------|-------|
 | `windows-x64` | `unlucky-launcher_<version>_windows_x64.exe` | bare `.exe`, double-click to run |
-| `windows-arm64` | `unlucky-launcher_<version>_windows_arm64.exe` | bare `.exe` |
+| `windows-arm64` | `unlucky-launcher_<version>_windows_arm64.exe` | bare `.exe` — **not yet published**, see below |
 | `linux-x64` | `unlucky-launcher_<version>_linux_x64.tar.gz` | one archive, one top-level directory |
 | `linux-arm64` | `unlucky-launcher_<version>_linux_arm64.tar.gz` | same |
 | `macos-arm64` | `unlucky-launcher_<version>_macos_arm64.tar.gz` | same |
@@ -213,6 +213,13 @@ Grab the file for your platform from
 | every slot | `ull_<version>_<platform>_<arch>[.exe]` | bare CLI binary, its own asset |
 | all | `SHA256SUMS.txt` | `sha256sum -c` eats it directly |
 
+`windows-arm64` is the one row documented but **not in the current release**: the CI ARM64 runner is
+missing the Windows SDK's ARM64 import libraries — the cause is located and the fix is in progress.
+The row stays because the architecture is still supported and the slot still builds (unpublished) in
+the matrix; what decides whether a slot reaches a Release is `PUBLISH_SLOTS` in
+`.github/workflows/release.yml`, which today names `windows-x64` only — so `windows-x64` is the
+only downloadable Windows asset.
+
 Each UNIX archive contains the executable plus `LICENSE`, `NOTICE` and `README.md`, in one top-level
 directory. Windows ships a bare `.exe` (a single file cannot carry the texts), so those three
 documents are attached to the release next to it — downloading the Windows binary does not strip the

README.zh-CN.md

@@ -167,7 +167,7 @@ unlucky-launcher --version                  # CLI，版本 + 系统摘要
 | 槽位 | 产物 | 形态 |
 |------|------|------|
 | `windows-x64` | `unlucky-launcher_<版本>_windows_x64.exe` | 裸 `.exe`，双击即用 |
-| `windows-arm64` | `unlucky-launcher_<版本>_windows_arm64.exe` | 裸 `.exe` |
+| `windows-arm64` | `unlucky-launcher_<版本>_windows_arm64.exe` | 裸 `.exe` —— **暂未发布**，见下 |
 | `linux-x64` | `unlucky-launcher_<版本>_linux_x64.tar.gz` | 单个归档，解压出一个顶层目录 |
 | `linux-arm64` | `unlucky-launcher_<版本>_linux_arm64.tar.gz` | 同上 |
 | `macos-arm64` | `unlucky-launcher_<版本>_macos_arm64.tar.gz` | 同上 |
@@ -175,6 +175,11 @@ unlucky-launcher --version                  # CLI，版本 + 系统摘要
 | 每个槽位 | `ull_<版本>_<平台>_<架构>[.exe]` | 裸 CLI 文件，独立资产 |
 | 全平台 | `SHA256SUMS.txt` | `sha256sum -c` 可直吃 |
 
+`windows-arm64` 是表里唯一「写了但**本次未发布**」的一行：CI 的 ARM64 runner 上缺 Windows SDK 的
+ARM64 导入库——原因已定位，正在修。这一行不删，是因为架构仍然要支持、槽位也仍在矩阵里构建（只是不进
+Release）；决定一个槽位能否进 Release 的是 `.github/workflows/release.yml` 里的 `PUBLISH_SLOTS`，
+它现在只写了 `windows-x64`——所以 `windows-x64` 是当前唯一可下载的 Windows 资产。
+
 UNIX 归档里是二进制加 `LICENSE`、`NOTICE`、`README.md`，都在一个顶层目录下。Windows 发的是裸 `.exe`
 （一个文件装不下这三份文本），所以这三份作为并列资产挂在 Release 上——下 Windows 二进制不会把许可条款
 弄丢。下载链接里不带实现细节字样，归档里的二进制名永远是 `unlucky-launcher`。