fix(docs): M118 r2 —— 发布页第二形态换成实测可用的 --renderer=cpu，NOTICE 停止声称 RF-2.0 已履行

复审 r2 的 2 条 P1 + 3 条 p2 小账，全部只动文档（5 份，0 个 .rs）。

P1-1（`SLINT_BACKEND` → `ICED_BACKEND` 换了个名字的死开关）：
`packaging/release-notes.md` 的「No GPU」小节原来把 `ICED_BACKEND=tiny-skia` 当作
`--software-renderer` 的等价替代命令给用户。实测该值会被本进程无条件覆盖：
- `ICED_BACKEND=tiny-skia ./unlucky-launcher-iced.exe --screenshot …`
  → `[probe] … request=auto -> ICED_BACKEND=wgpu` / `[shot] … renderer=wgpu` / `[backend] final=wgpu`
- `--software-renderer --screenshot …` → `request=cpu -> ICED_BACKEND=tiny-skia` / `renderer=tiny-skia`
- `--renderer=cpu --screenshot …`      → `request=cpu -> ICED_BACKEND=tiny-skia` / `renderer=tiny-skia`
所以改成两条都实测可用的形态（`--software-renderer` / `--renderer=cpu`），不再把环境变量当用户开关。

P1-2（RF-2.0 履行方式的措辞与上游 §2 冲突）：
`NOTICE` 第 1 条原写「由 v0.1.0 的 NOTICE、发布页说明与本文件的历史记录共同承担」——§2 只承认
(a) AboutSlint 部件 / (b) 公开下载页的官方徽章两种履行，NOTICE 文本不是履行。改为：义务仍挂在
v0.1.0 已发布资产上（条件挂在每次分发，不挂版本号）；§2 只承认两种形式；**按本仓库记录，该项义务
在 v0.1.0 上尚未以任一形式落地**（部件一直只有排期，发布页那行是文字链接不是徽章图）；NOTICE /
发布页说明 / 本节都只是记录。

p2 小账：
- `NOTICE` 第 3 条的依赖许可：`tiny-skia` 从「Apache-2.0 / MIT」改正为 BSD-3-Clause，并把
  winit（Apache-2.0）/ wgpu（MIT OR Apache-2.0）分别写明；README（中英）同款写法一并对齐。
- `packaging/README.md` §4：`libGL/libEGL` 行改成「Slint 版 femtovg / iced 版 wgpu（推断，未实测）」，
  并把限定语改成「除标注『推断，未实测』的那一行外，整表是 Slint 版实测」，消除表内与限定语打架。
- `README.md` / `README.zh-CN.md` 的 Slint 义务段补 `v0.1.0` 限定并按 §2 口径重写，避免读者以为
  「Made with Slint」说的是下一版。

证据：`git diff --name-only` = NOTICE, README.md, README.zh-CN.md, packaging/README.md,
packaging/release-notes.md；`packaging/README.md` 仍 399 行（守卫上限 400）；release body 模板用
`{{VERSION}}=0.2.0` 渲染通过（5956 字符，全篇 Slint 命中 4 行，均在「本版不含 Slint」的解释段）。

README.md

@@ -229,14 +229,17 @@ Minimum baseline: **Windows 10**; Windows 8.1 / 8 / 7 are not supported.
 
 - **This project**: Apache License 2.0, see [LICENSE](LICENSE); third-party notices in
   [NOTICE](NOTICE).
-- **Slint** (<https://slint.dev>), Royalty-Free 2.0: obligation for the Slint build that v0.1.0
-  ships — an `AboutSlint` widget on the about page (still outstanding) and, until it lands, the
-  NOTICE file, this section and a "Made with Slint" note on the release page. The obligation follows
-  a **Slint-linked binary**: it applies to the v0.1.0 assets (and to any later build that links Slint
-  again), not to new iced builds — `crates/app` is excluded from the workspace, so the pipeline no
-  longer produces a Slint-linked binary.
-- **iced** (<https://github.com/iced-rs/iced>), MIT: the framework of the next-generation UI,
-  together with `winit` and, through it, `wgpu` / `tiny-skia` (Apache-2.0 / MIT).
+- **Slint** (<https://slint.dev>), Royalty-Free 2.0: obligation for the Slint build that `v0.1.0`
+  ships. Upstream §2 admits exactly two ways to discharge it — an `AboutSlint` widget on an about
+  screen, or the official Slint attribution badge on a public download page. By this repository's own
+  record that obligation has **not yet been discharged in either form** for `v0.1.0`: the widget was
+  only ever scheduled, and the `v0.1.0` release page carries a text link rather than the badge. The
+  `v0.1.0` NOTICE, that page's text and this section are **records, not discharge**. The obligation
+  follows a **Slint-linked binary**: it applies to the `v0.1.0` assets (and to any later build that
+  links Slint again), not to new iced builds — `crates/app` is excluded from the workspace, so the
+  pipeline no longer produces a Slint-linked binary.
+- **iced** (<https://github.com/iced-rs/iced>), MIT: the framework of the UI, together with `winit`
+  (Apache-2.0) and, through it, `wgpu` (MIT / Apache-2.0) / `tiny-skia` (BSD-3-Clause).
 - **Google Material Color Utilities** (Apache-2.0): the color tokens in `crates/design` are a Rust
   port of its HCT / ColorSpec2021 algorithms; details and the exact ported functions are listed in
   [NOTICE](NOTICE).