chore(release): M137 版本升到 0.2.1，发布只发两个 Windows 槽位

版本：`[workspace.package] version` 0.2.0 → 0.2.1，并把全部 intra-workspace path
依赖的 version 约束一并对齐（`"0.2"` → `"0.2.1"`，M121 的教训）。Cargo.lock 里只有
8 个 unlucky-* 成员条目变化。`crates/app` 是 workspace `exclude` 的 Slint 退役树（manifest
连解析都过不了），不参与解析，故原样保留。

release.yml：新增 `PUBLISH_SLOTS` 白名单（唯一开关）＝ `windows-x64 windows-arm64`。
六槽位一律构建取证，release job 先按白名单裁掉 Linux/macOS 四档产物再重算 SHA256SUMS，
所以 tag 触发的 Release 只有 4 个资产 + SHA256SUMS.txt。release job 改成
`always() && !cancelled()`：未验证槽位构建失败不连坐 Windows 发布，真正的门禁是白名单
齐全性检查。将来某槽位真机验过后把它加进那一行即打开。

顺手修掉一处从未生效的门禁：齐全性检查的 glob 用的是连字符形态
（`dist/$prefix-*-$slot*`），对 D49 之后的下划线资产名永远匹配不上，改成
`dist/${prefix}_*_${stem}*`。资产命名规则 / SHA256SUMS / 合规文本并列资产 /
`--version` 与 tag 交叉校验一律未动。

packaging/release-notes.md：清掉 v0.1.0 / Slint 时代的说明，Downloads 与 Support matrix
只描述本版实际发布的 Windows 两个槽位（其余标「built by CI, not published」）。
packaging/README.md §1/§3/§9 同步 gate（矩阵加「本版发布」列、§3 写清白名单与打开办法）。
起手顺带把示例 tag 从 v0.2.0 更到 v0.2.1，并把「winit / femtovg」更正为「winit / wgpu」。

packaging/release-notes.md

@@ -13,21 +13,24 @@ Asset names are `<name>_<version>_<platform>_<arch>`, underscore separated — t
 | --- | --- | --- |
 | Windows 10/11 x64 | `unlucky-launcher_{{VERSION}}_windows_x64.exe` | single exe, double-click to run |
 | Windows 11 ARM64 | `unlucky-launcher_{{VERSION}}_windows_arm64.exe` | single exe, runs natively on ARM64 Windows |
-| Linux x64 (X11/Wayland) | `unlucky-launcher_{{VERSION}}_linux_x64.tar.gz` | single binary inside, no installer |
-| Linux arm64 (X11/Wayland) | `unlucky-launcher_{{VERSION}}_linux_arm64.tar.gz` | single binary inside; needs glibc 2.35+ |
-| macOS 12+ Apple Silicon | `unlucky-launcher_{{VERSION}}_macos_arm64.tar.gz` | single binary inside, no installer |
-| macOS 12+ Intel | `unlucky-launcher_{{VERSION}}_macos_x64.tar.gz` | single binary inside, no installer |
 
-Each archive unpacks to one top-level directory of the same name holding the binary plus `LICENSE`,
-`NOTICE` and `README.md`; the Windows assets are bare `.exe` files, so those three documents are attached
-to this release next to them — the license terms travel with every download.
+**This release ships Windows only.** The Linux (x64 / arm64) and macOS (Apple Silicon / Intel) slots are
+built by CI but are not assets of this release: they have not been verified on real machines yet, so
+nothing unverified is handed out. They stay out of the download list and out of `SHA256SUMS.txt` until
+that verification happens — the support matrix below marks them accordingly.
 
-Every slot also ships the command line as its own small bare asset,
+The Windows assets are bare `.exe` files, so `LICENSE`, `NOTICE` and `README.md` are attached to this
+release next to them: the license terms travel with every download. Slots that ship an archive (Linux /
+macOS, once published) unpack to one top-level directory of the same name holding the binary plus those
+three documents.
+
+## Command line
+
+Each published slot also ships the command line as its own small bare asset,
 `ull_{{VERSION}}_<platform>_<arch>` (`.exe` on Windows):
 
-```bash
-chmod +x ull_{{VERSION}}_linux_x64            # release assets carry no executable bit
-./ull_{{VERSION}}_linux_x64 instances list    # servers and CI: no graphics stack needed
+```powershell
+.\ull_{{VERSION}}_windows_x64.exe instances list   # servers and CI: no graphics stack needed
 ```
 
 `ull` runs `instances`, `install`, `pack import`, `launch`, `accounts`, `sessions`, `logs`, `diag`,
@@ -36,37 +39,36 @@ before it ever opens a window, so a desktop machine does not need `ull`.
 
 ## Support matrix
 
-| Platform | Level | Runtime requirements |
-| --- | --- | --- |
-| Windows 10/11 x64 | first class | nothing beyond the OS (UCRT is part of Win10+) |
-| Windows 11 ARM64 | first class (launcher artifact) | nothing extra; the launcher runs natively, the game itself runs through the OS x64 emulation layer with an x64 JDK |
-| macOS 12+ (arm64 / x64) | first class | nothing; unsigned build, see the Gatekeeper note |
-| Linux x64, X11 | first class | `libxkbcommon`, `fontconfig`, `libGL` (or software renderer), `libxcb` |
-| Linux x64, Wayland | supported | `wayland-client`, `libxkbcommon`, plus the X11 set for XWayland apps |
-| Linux arm64, X11 | first class | glibc 2.35+ (same floor as x64), `libxkbcommon`, `fontconfig`, `libGL`, `libxcb` |
-| Linux arm64, Wayland | supported | the above plus `wayland-client` |
-| Windows 8.1/8/7 | unsupported | the baseline is Windows 10 |
-| Android — Termux + X11 | experimental, not promised | CLI only and only when built from source; GUI unverified; not part of this release matrix |
+Published = shipped as a download of **this** release, listed in `SHA256SUMS.txt`.
 
-Both arm64 rows are **formally released slots** (assets ship here and in `SHA256SUMS.txt`), not the
-experimental Termux path: Linux arm64 is built and smoke-tested on a native ARM64 runner, Windows ARM64 is
-cross-built with the same static-CRT gate as x64.
+| Platform | Status in this release | Level | Runtime requirements |
+| --- | --- | --- | --- |
+| Windows 10/11 x64 | **published** | first class | nothing beyond the OS (UCRT is part of Win10+) |
+| Windows 11 ARM64 | **published** | first class (launcher artifact) | nothing extra; the launcher runs natively, the game itself runs through the OS x64 emulation layer with an x64 JDK |
+| macOS 12+ Apple Silicon | built by CI, not published | first class (unverified) | nothing; unsigned build, needs the Gatekeeper workaround |
+| macOS 12+ Intel | built by CI, not published | first class (unverified) | same as above |
+| Linux x64, X11 | built by CI, not published | first class (unverified) | `libxkbcommon`, `fontconfig`, `libGL` (or software renderer), `libxcb` |
+| Linux x64, Wayland | built by CI, not published | supported (unverified) | `wayland-client`, `libxkbcommon`, plus the X11 set for XWayland apps |
+| Linux arm64, X11 | built by CI, not published | first class (unverified) | glibc 2.35+, `libxkbcommon`, `fontconfig`, `libGL`, `libxcb` |
+| Linux arm64, Wayland | built by CI, not published | supported (unverified) | the above plus `wayland-client` |
+| Windows 8.1/8/7 | not built | unsupported | the baseline is Windows 10 |
+| Android — Termux + X11 | not built (no CI slot) | experimental, not promised | CLI only and only when built from source; GUI unverified |
+
+Both arm64 rows are formal matrix slots, not the experimental Termux path: Windows ARM64 ships here and
+is cross-built with the same static-CRT gate as x64; Linux arm64 builds on a native ARM64 runner and
+joins this list once someone has run it on real hardware. The rows above and the matrix table in
+`packaging/README.md` §9 are the same list — change one, change the other.
 
 ## Install
 
 **Windows** — put the `.exe` anywhere and run it (pick `_windows_arm64.exe` on ARM64 Windows,
 `_windows_x64.exe` everywhere else). The first run creates `.ULL/` and `.minecraft/` next to the exe
-(portable is the default data mode); the per-user `%APPDATA%\ULL` plus `%APPDATA%\.minecraft`, or a custom
-root, are selectable instead.
+(portable is the default data mode); the per-user `%APPDATA%\ULL` plus `%APPDATA%\.minecraft`, or a
+custom root, are selectable instead.
 
-**Linux / macOS**
-
-```bash
-tar -xzf unlucky-launcher_{{VERSION}}_linux_x64.tar.gz   # _linux_arm64 on aarch64; _macos_arm64 / _macos_x64 on macOS
-cd unlucky-launcher_{{VERSION}}_linux_x64                # ditto
-xattr -d com.apple.quarantine unlucky-launcher           # macOS only: unsigned build, Gatekeeper
-chmod +x unlucky-launcher && ./unlucky-launcher
-```
+Linux / macOS are not part of this release; their asset names are already fixed by the same rule
+(`unlucky-launcher_{{VERSION}}_linux_x64.tar.gz`, `_linux_arm64`, `_macos_arm64`, `_macos_x64`) so the
+links will not change shape when those slots open.
 
 ## No GPU? Software renderer
 
@@ -75,8 +77,11 @@ adapter is present; `--software-renderer` (or its equivalent `--renderer=cpu`) f
 
 ## Verify the download
 
+`SHA256SUMS.txt` lists exactly the assets attached to this release (Windows only), and `sha256sum -c`
+checks the ones you actually downloaded:
+
 ```bash
-sha256sum -c SHA256SUMS.txt --ignore-missing   # Linux
+sha256sum -c SHA256SUMS.txt --ignore-missing   # Linux / WSL
 shasum -a 256 -c SHA256SUMS.txt                # macOS (sha256sum is not bundled)
 Get-FileHash .\unlucky-launcher_{{VERSION}}_windows_x64.exe -Algorithm SHA256   # Windows PowerShell
 ```
@@ -97,8 +102,8 @@ Get-FileHash .\unlucky-launcher_{{VERSION}}_windows_x64.exe -Algorithm SHA256
   command line. Offline profiles and authlib-injector servers need no id.
 - Binaries are not code-signed / notarized yet: Windows SmartScreen and macOS Gatekeeper warn on first
   launch. The checksums above are the integrity reference for now.
-- macOS ships the bare binary (single-file promise), not a `.app` bundle: no Dock icon or Finder
-  double-click — launch it from a terminal.
+- When the macOS slot ships it is the bare binary (single-file promise), not a `.app` bundle: no Dock
+  icon or Finder double-click — launch it from a terminal.
 
 ## License
 
@@ -106,7 +111,5 @@ Apache-2.0, third-party notices in `NOTICE`. Not affiliated with Mojang or Micro
 
 ## UI framework in this build
 
-Every asset here is built from the iced UI (`crates/app-iced`, iced 0.14, MIT); no Slint code is linked
-into it. The earlier Slint UI (`crates/app`) stays in the repository as historical source only —
-excluded from the workspace, not built, in no asset and in no release slot. The Slint Royalty-Free 2.0
-attribution it carried belongs to the `v0.1.0` release and remains where it was published.
+Every asset here is built from the iced UI (`crates/app-iced`, iced 0.14, MIT); no other UI framework is
+linked into it.