fix(docs): M118 r3 —— 撤回「AboutSlint 从未落地」的假前提，改为中性陈述 + 不作法律判断

复审 r3 的唯一 P1：r2 为了论证「未履行」，断言「`AboutSlint` 部件一直只有排期、从未落地」。
**这条是错的**，我先自己核了源码再改：

```
$ git grep -n 'AboutSlint' crates/app/
crates/app/ui/pages/settings.slint:4:// 关于页内嵌 AboutSlint —— Slint RF 2.0 许可义务（01c §8：关于页放官方部件）。
crates/app/ui/pages/settings.slint:15:import { AboutSlint, ScrollView } from "std-widgets.slint";
crates/app/ui/pages/settings.slint:274:                        AboutSlint { }
$ git grep -n 'AboutSlint' v0.1.0 -- crates/
（同上三行，v0.1.0 这个 tag 里就有）
$ sed -n '272,275p' crates/app/ui/pages/settings.slint
if root.section == SettingSection.about : Rectangle { height: 120px; AboutSlint { } }
$ sed -n '129p' crates/app/ui/pages/settings.slint   → SectionRow { label: "关于"; … }
$ grep -n 'RouteKind.settings' crates/app/ui/components/nav.slint → :114/:116（侧栏入口）
$ grep -n compile crates/app/build.rs → slint_build::compile("ui/main.slint")
$ grep -n SettingsPage crates/app/ui/shell.slint → :23 import / :273 route==settings 时渲染
```

即：部件真实存在、经 build.rs 编译进二进制、侧栏 → 设置页「关于」一点即到；`packaging/README.md:317`
「（已在 UI 内）」本来就与代码一致，本轮未改。r2 的依据只是三份文档的自述（旧 NOTICE「P2 排期」、
README「still outstanding」），那份自述不可靠。

改法（三处同一句，`packaging/release-notes.md` 不动）：
- 删掉「只有排期 / 从未落地 / 尚未以任一形式落地」这类断言；
- 改成中性陈述：义务挂在每次「随应用分发」上；`v0.1.0` 的设置页「关于」分组里**确实内置了**
  `AboutSlint` 部件（`crates/app/ui/pages/settings.slint`，从侧栏进入）；该部件是否满足 §2(a)、
  以及 v0.1.0 发布页上是文字链接而非 §2(b) 官方徽章图这两点，**本文件不作法律判断**，以 Slint
  官方许可原文为准；NOTICE / 发布页说明 / 本节都只是记录，不构成履行声明。
- 顺手按本机 registry 里 Slint 1.18.1 随包的 RF-2.0 原文把 §2(a) 补全：还允许「没有关于页时显示在
  启动画面」这一变体（原文 `In the absence of such a screen or dialog, display the widget in the
  "Splash Screen"`），r2 只写了前半句。

diff：`git diff --name-only` = NOTICE, README.md, README.zh-CN.md（3 份文档、零 .rs）。

README.md

@@ -230,14 +230,18 @@ 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. 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
+  ships — the condition attaches to each distribution of an Application, not to a version number.
+  Upstream §2 offers two forms: (a) the official `AboutSlint` widget on an "About" screen or dialog
+  reachable from the top level menu (or the splash screen when there is none); (b) the official Slint
+  attribution badge on a public page where the binaries can be downloaded. **`v0.1.0`'s settings page
+  does embed the `AboutSlint` widget** (`crates/app/ui/pages/settings.slint`, reachable from the
+  sidebar); whether that satisfies §2(a), and the fact that the `v0.1.0` release page carries a text
+  link rather than the §2(b) badge, are **not judged here** — Slint's own licence text is the
+  authority. The `v0.1.0` NOTICE, that page's text and this section are **records, not a statement of
+  discharge**. Later builds link no Slint, so they add nothing to this obligation. 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.
+  pipeline no longer produces one.
 - **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