chore(release): v0.8.0 — language switching (EN / 繁中 / 简中)

Bump version to 0.8.0, add the About-dialog changelog entry in all
three language packs, and add release notes crediting @CarmJos (#1).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/release-notes/v0.8.0.md

@@ -0,0 +1,33 @@
+# v0.8.0 — Switch languages: English, 繁體中文, 简体中文
+
+## ✨ New features
+
+**Language switching**
+* Pick **English**, **繁體中文** or **简体中文** from **View → Language** or the language box on the quick toolbar. The whole interface switches instantly — menus, dialogs, status messages, and even measurements already on screen — and your choice is remembered next time.
+* On first launch STPViewer follows your Windows display language (Traditional Chinese regions → 繁體中文, other Chinese → 简体中文, everything else → English).
+
+**Add your own language — no update needed**
+* Languages are plain JSON files in the `i18n` folder next to `STPViewer.exe`. Copy `en.json`, translate it, save it under a new name, and restart — the new language appears in the menu. Anything not yet translated falls back to English. See [Adding a Language](https://github.com/ETWen/STPViewer#-adding-a-language) in the README.
+
+**Simplified Chinese README**
+* The README is now also available in [简体中文](https://github.com/ETWen/STPViewer/blob/main/README.zh-CN.md).
+
+## 🙏 Thanks
+
+* Multi-language support was contributed by **@CarmJos** in [#1](https://github.com/ETWen/STPViewer/pull/1) — thank you!
+
+## 📦 Downloads
+
+| Build | Needs .NET Runtime? | Notes |
+|---|---|---|
+| **STPViewer_v0.8.0** (Standard) | ✅ Requires .NET 8 Desktop Runtime | Smaller download |
+| **STPViewer_v0.8.0_portable** (Portable) | ❌ Runtime included | Unzip and run anywhere, no admin |
+
+Run `STPViewer v0.8.0.exe`. Keep the `i18n` folder next to it — that's where the languages live.
+
+## 🔗 Links
+
+* [Architecture](https://github.com/ETWen/STPViewer/blob/main/ARCHITECTURE.md)
+* [README](https://github.com/ETWen/STPViewer/blob/main/README.md)
+
+**Full changelog:** [v0.7.1...v0.8.0](https://github.com/ETWen/STPViewer/compare/v0.7.1...v0.8.0)

src/STPViewer/AboutDialog.xaml.cs

@@ -29,6 +29,13 @@ public partial class AboutDialog : Window
     // ── 版本紀錄（新版加最上面；口吻：一般使用者看得懂，講「你會感覺到什麼」而非實作細節）──
     private static readonly ChangelogEntry[] Changelog =
     {
+        new("0.8.0", new DateOnly(2026, 10, 20), "Ui.About.Release080.Title",
+        new[]
+        {
+            "Ui.About.Release080.Change1",
+            "Ui.About.Release080.Change2",
+            "Ui.About.Release080.Change3",
+        }),
         new("0.7.1", new DateOnly(2026, 7, 12), "Ui.About.Release071.Title",
         new[]
         {

src/STPViewer/STPViewer.csproj

@@ -6,7 +6,7 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <UseWPF>true</UseWPF>
-    <Version>0.7.1</Version>   <!-- Shared by the window title and publish output. -->
+    <Version>0.8.0</Version>   <!-- Shared by the window title and publish output. -->
   </PropertyGroup>
 
   <ItemGroup>

src/STPViewer/i18n/en.json

@@ -250,6 +250,10 @@
     "Ui.About.Release071.Change1": "• Large STL mesh files with millions of triangles now open almost instantly instead of taking several minutes.",
     "Ui.About.Release071.Change2": "• For example, a 75 MB STL with 1.5 million triangles now appears in under a second.",
     "Ui.About.Release071.Title": "Open Large STL Files in Seconds",
+    "Ui.About.Release080.Change1": "• Choose English, 繁體中文 or 简体中文 from View → Language or the quick toolbar. The whole interface switches instantly — including measurements already on screen — and your choice is remembered.",
+    "Ui.About.Release080.Change2": "• Languages are plain files in the i18n folder next to the program: drop in a new one and it shows up in the menu, no update needed. Anything not yet translated falls back to English.",
+    "Ui.About.Release080.Change3": "• Thanks to @CarmJos for contributing this feature.",
+    "Ui.About.Release080.Title": "Switch Languages: English, Traditional & Simplified Chinese",
     "Ui.About.Technology": ".NET 8 · WPF · C#; CADability (STEP / B-rep geometry); HelixToolkit (3D display and camera)",
     "Ui.About.TechnologyTitle": "🔧  Technology",
     "Ui.About.Title": "About STPViewer",

src/STPViewer/i18n/zh_cn.json

@@ -250,6 +250,10 @@
     "Ui.About.Release071.Change1": "• 打开大型 STL 网格文件（数十 MB、上百万三角形）现在几乎瞬间完成，不用再等好几分钟。",
     "Ui.About.Release071.Change2": "• 例如一个 75 MB、150 万个三角形的 STL，以前要等到天荒地老，现在不到 1 秒就显示出来。",
     "Ui.About.Release071.Title": "大型 STL 秒开",
+    "Ui.About.Release080.Change1": "• 在「视图 → 语言」或快速栏即可切换 English、繁體中文、简体中文，整个界面立即更换（连画面上已经测量好的结果也会跟着换），下次打开会记住。",
+    "Ui.About.Release080.Change2": "• 语言是程序旁 i18n 文件夹里的普通文件：放一个新的进去，菜单就多一种语言，无需更新程序。尚未翻译的文字会先以英文显示。",
+    "Ui.About.Release080.Change3": "• 感谢 @CarmJos 贡献这项功能。",
+    "Ui.About.Release080.Title": "语言切换：英文／繁体中文／简体中文",
     "Ui.About.Technology": ".NET 8 · WPF · C#；CADability（STEP / B-rep 几何内核）；HelixToolkit（3D 显示与相机）",
     "Ui.About.TechnologyTitle": "🔧  技术栈",
     "Ui.About.Title": "关于 STPViewer",

src/STPViewer/i18n/zh_tw.json

@@ -250,6 +250,10 @@
     "Ui.About.Release071.Change1": "• 開啟大型 STL 網格檔（數十 MB、上百萬三角形）現在幾乎瞬間完成，不用再等好幾分鐘。",
     "Ui.About.Release071.Change2": "• 例如一個 75 MB、150 萬個三角形的 STL，以前要等到天荒地老，現在不到 1 秒就顯示出來。",
     "Ui.About.Release071.Title": "大型 STL 秒開",
+    "Ui.About.Release080.Change1": "• 到「視圖 → 語言」或快速列就能切換 English、繁體中文、简体中文，整個介面立刻換掉（連畫面上已經量好的結果也會跟著換），下次開啟會記住。",
+    "Ui.About.Release080.Change2": "• 語言是程式旁 i18n 資料夾裡的一般檔案：放一個新的進去，選單就多一種語言，不用更新程式。還沒翻譯到的文字會先用英文顯示。",
+    "Ui.About.Release080.Change3": "• 感謝 @CarmJos 貢獻這項功能。",
+    "Ui.About.Release080.Title": "語言切換：英文／繁體中文／簡體中文",
     "Ui.About.Technology": ".NET 8 · WPF · C#；CADability（STEP / B-rep 幾何核心）；HelixToolkit（3D 顯示與相機）",
     "Ui.About.TechnologyTitle": "🔧  技術棧",
     "Ui.About.Title": "關於 STPViewer",