refactor: 重构项目结构并更新命名规范

- 更新项目目录名为 app-desktop 以反映新的项目结构命名规范
- 添加应用桌面模块并移除已弃用的 tauri-shell 包依赖
- 更新项目名称和库名称以反映新的应用标识
- 将主函数中的启动逻辑从 tauri_shell_lib 改为 app_desktop_lib
- 更新应用名称和标识符以反映新的项目名称。

src-tauri/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "tauri-shell"
+name = "app-desktop"
 version = "0.1.0"
 description = "A Tauri App"
 authors = ["imbytecat"]
@@ -11,7 +11,7 @@ edition = "2021"
 # The `_lib` suffix may seem redundant but it is necessary
 # to make the lib name unique and wouldn't conflict with the bin name.
 # This seems to be only an issue on Windows, see https://github.com/rust-lang/cargo/issues/8519
-name = "tauri_shell_lib"
+name = "app_desktop_lib"
 crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]