feat(desktop): embed BoosAPI Desktop client as a subproject

Vendor the rebranded BoosAPI Desktop client (Tauri + Vue) into metapi as
a monorepo subdirectory under desktop/. Source only — node_modules,
dist, Cargo target and the upstream .git history are excluded.

desktop/ keeps its own independent Cargo workspace (desktop/src-tauri
with crates/*); it is not part of the backend boosapi crate, so a
`cargo check` at the metapi root still compiles only the backend. Build
the desktop app from desktop/src-tauri per desktop/README.md.

Note: app icons are still placeholder assets pending the final BoosAPI
logo. The updater signing keys live outside the repo and are not
included.

desktop/website/docs/zh-tw/index.md

@@ -0,0 +1,57 @@
+---
+layout: home
+title: "BoosApi — 開源 AI 桌面客戶端與閘道"
+titleTemplate: false
+
+head:
+  - - meta
+    - name: description
+      content: "BoosApi 是免費開源的 AI 桌面客戶端，支援多模型對話、Agent、MCP、ChatGPT/Cherry Studio/Kelivo 匯入、本機知識庫、S3/WebDAV 備份和內建 AI 閘道。"
+
+hero:
+  name: BoosApi
+  text: "你的 AI 桌面工作台"
+  tagline: "多模型對話、Agent、MCP 工具、API 閘道、資料匯入、知識庫和備份整合在一個本機優先客戶端裡"
+  image:
+    src: /logo.png
+    alt: BoosApi
+  actions:
+    - theme: brand
+      text: "快速開始"
+      link: /zh-tw/guide/getting-started
+    - theme: alt
+      text: "下載"
+      link: /zh-tw/download
+    - theme: alt
+      text: GitHub
+      link: https://github.com/BoosApi-Desktop/BoosApi
+
+features:
+  - icon: robot
+    title: "多模型對話"
+    details: "OpenAI、Claude、Gemini、DeepSeek、Qwen 和相容 API，支援金鑰輪詢、分支、壓縮和多模型回答。"
+  - icon: api
+    title: "服務供應商快速設定"
+    details: "boosapi:// 連結、CC Switch 匯入、自訂請求頭、代理、OpenAI Responses 和模型 extra_body。"
+  - icon: thunderbolt
+    title: "AI Agent"
+    details: "檔案編輯、命令執行和程式碼分析，帶權限分級、工作目錄沙箱、審批 UI 和成本統計。"
+  - icon: edit
+    title: "富內容渲染"
+    details: "Markdown、LaTeX、Mermaid、D2、Monaco 程式碼區塊、HTML 片段和 Artifact 預覽。"
+  - icon: search
+    title: "搜尋與 RAG"
+    details: "帶引用的網路搜尋、查詢生成、本機 sqlite-vec 知識庫、重排設定和檢索回饋。"
+  - icon: cloud-server
+    title: "API 閘道"
+    details: "本機 OpenAI 相容、OpenAI Responses、Claude 和 Gemini 介面，服務 Claude Code、Codex、OpenCode 等工具。"
+  - icon: book
+    title: "資料匯入"
+    details: "匯入 ChatGPT 官方匯出、Cherry Studio 與 Kelivo 備份，處理重複並可遷移服務供應商。"
+  - icon: lock
+    title: "備份與安全"
+    details: "AES-256 本機加密、雙目錄資料布局、本機/WebDAV/S3 備份和還原流程。"
+  - icon: desktop
+    title: "桌面體驗"
+    details: "11 種界面語言、系統匣、置頂、全域快捷鍵、開機自啟、代理和自動更新檢查。"
+---