```

feat(dev): 添加开发服务器与热重载支持

- 新增 `npm run dev` 命令，启动带热重载的开发服务器
- 集成 rollup watch 模式与 LiveReload 实现自动刷新
- 添加开发指南 DEVELOPMENT.md，说明项目结构、预览方式及构建流程
- 新增开发预览页面 index.html，用于嵌入展示 sidepanel 内容
- 更新 package.json 和 package-lock.json，引入相关开发依赖
```

package.json

@@ -3,11 +3,17 @@
   "version": "1.1",
   "type": "module",
   "scripts": {
-    "build": "rollup -c"
+    "build": "rollup -c",
+    "dev": "rollup -c -w"
   },
   "private": true,
   "devDependencies": {
     "@google/generative-ai": "0.15.0",
-    "rollup": "4.22.4"
+    "@rollup/plugin-commonjs": "^25.0.8",
+    "@rollup/plugin-json": "^6.1.0",
+    "@rollup/plugin-node-resolve": "^15.3.1",
+    "rollup": "4.22.4",
+    "rollup-plugin-livereload": "^2.0.5",
+    "rollup-plugin-serve": "^3.0.0"
   }
-}
+}