feat: 添加 VitePress 文档站和 Gitea CI 部署

- 新增 docs/ 目录，使用 VitePress 构建文档站
- 添加 .gitea/workflows/deploy.yaml，部署到 Cloudflare Pages
- 新增 setup.sh 一站式安装脚本（兼容 macOS bash 3.x）
- 修复 Gemini CLI 脚本认证头（改用 Authorization: Bearer）

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "xcodecli-docs",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vitepress dev",
+    "build": "vitepress build",
+    "preview": "vitepress preview"
+  },
+  "devDependencies": {
+    "vitepress": "^1.5.0"
+  }
+}