feat: 添加 Tauri 桌面应用

- 创建 packages/desktop 模块
- 实现 Tauri 2.0 + React 桌面应用
- 复用 Web 前端代码
- 添加系统托盘功能
- 实现本地文件访问命令
- 配置 Vite + Tauri 集成
- 更新 .gitignore 添加 Rust/Tauri 相关规则

packages/desktop/src-tauri/tauri.conf.json

@@ -0,0 +1,55 @@
+{
+  "$schema": "https://schema.tauri.app/config/2",
+  "productName": "AI Assistant",
+  "version": "1.0.0",
+  "identifier": "com.ai-assistant.desktop",
+  "build": {
+    "beforeDevCommand": "pnpm dev:vite",
+    "devUrl": "http://localhost:5199",
+    "beforeBuildCommand": "pnpm build:vite",
+    "frontendDist": "../dist"
+  },
+  "app": {
+    "withGlobalTauri": true,
+    "windows": [
+      {
+        "title": "AI Assistant",
+        "width": 1200,
+        "height": 800,
+        "minWidth": 800,
+        "minHeight": 600,
+        "resizable": true,
+        "fullscreen": false,
+        "center": true
+      }
+    ],
+    "security": {
+      "csp": null
+    },
+    "trayIcon": {
+      "iconPath": "icons/icon.png",
+      "iconAsTemplate": true
+    }
+  },
+  "bundle": {
+    "active": true,
+    "targets": "all",
+    "icon": [
+      "icons/32x32.png",
+      "icons/128x128.png",
+      "icons/128x128@2x.png",
+      "icons/icon.icns",
+      "icons/icon.ico"
+    ],
+    "macOS": {
+      "minimumSystemVersion": "10.15"
+    },
+    "windows": {
+      "wix": null,
+      "nsis": {
+        "installMode": "currentUser"
+      }
+    }
+  },
+  "plugins": {}
+}