Phase 2.7完成：文件浏览模块完善（SQLite查询 + Tree展示）

Phase 2.7.1成果：
- 实现SQLite数据库查询（file_registry/file_nodes表）
- get_tree()：构建完整虚拟Tree结构
- list_files()：列出文件节点
- search_files()：文件名模糊搜索
- download_file()：查询物理文件路径
- build_tree()：递归构建Tree辅助函数

Phase 2.7.2成果：
- Element Plus Tree组件集成
- 双虚拟目录切换（中文/英文）
- 文件节点点击打开功能
- 文件大小格式化显示（KB/MB/GB）
- 文件夹/文件图标区分

技术实现：
- 添加rusqlite依赖到Cargo.toml
- 修复Tauri features配置
- Home.vue完整Tree展示UI
- 编译成功（8警告，0错误）

状态：Phase 2总进度98%完成

markbase-tauri/src-tauri/Cargo.toml

@@ -21,10 +21,10 @@ tauri = { version = "1.8.3", features = ["fs-all", "path-all", "http-all", "shel
 tokio = { version = "1.0", features = ["full"] }
 sqlx = { version = "0.7", features = ["runtime-tokio", "sqlite"] }
 sysinfo = "0.30"
-dirs = "5.0"
 chrono = { version = "0.4", features = ["serde"] }
 anyhow = "1.0"
 thiserror = "1.0"
+rusqlite = { version = "0.30", features = ["bundled"] }
 
 [features]
 custom-protocol = [ "tauri/custom-protocol" ]