[feat] add HarmonyOS desktop and mobile clients，issue #117

docs/BUILD.md

@@ -9,6 +9,8 @@
 - Git、[Xmake](https://xmake.io/guide/quick-start.html)（桌面端和移动端均要求 3.1.1 或更新版本）及下文对应平台的编译工具链。
 - 构建脚本通过 Xmake 管理 **CMake 3.x（≥ 3.21、< 4.0）**、**Rust 1.92.0** 等依赖；首次构建需要下载工具与源码。具体约束见 [Slint 包配置](../deps/thirdparty/slint/xmake.lua)。
 
+鸿蒙 PC 的 Slint 移植直接编译桌面公共界面和业务代码，见 [Slint 桌面构建与一致性验收](../apps/harmony/desktop-port/README.md)（API 26）。独立 ArkUI 手机 / 平板工程见 [HarmonyOS 构建与真机验证](../apps/harmony/README.md)。请使用各自说明中的脚本，不要通过桌面根工程切换鸿蒙配置。
+
 ## Windows
 
 安装 Visual Studio 2022 的“使用 C++ 的桌面开发”工作负载、Windows SDK 和“适用于 Windows 的 C++ Clang 编译器”组件，并安装 Xmake。Windows x64 的 libyuv 使用 clang-cl 编译，以启用 SIMD 图像转换和缩放；主程序仍使用 MSVC。在开发者 PowerShell 中执行：

docs/BUILD_EN.md

@@ -9,6 +9,8 @@ After cloning, run build and packaging commands from the repository root. The [X
 - Git, [Xmake](https://xmake.io/guide/quick-start.html) (3.1.1 or newer for both desktop and mobile), and the platform toolchain listed below.
 - The build scripts use Xmake to manage **CMake 3.x (≥ 3.21, < 4.0)**, **Rust 1.92.0**, and other dependencies. The first build downloads tools and source archives. See the [Slint package configuration](../deps/thirdparty/slint/xmake.lua) for the constraints.
 
+The HarmonyOS Slint desktop port compiles the shared desktop UI and application logic; see its [build and parity validation guide (Chinese)](../apps/harmony/desktop-port/README.md) (API 26). The separate ArkUI phone / tablet project is documented in the [HarmonyOS guide (Chinese)](../apps/harmony/README.md). Use the respective scripts instead of reconfiguring the desktop root project.
+
 ## Windows
 
 Install Visual Studio 2022 with the **Desktop development with C++** workload, Windows SDK, and **C++ Clang Compiler for Windows** component, plus Xmake. Windows x64 builds use clang-cl for libyuv to enable SIMD conversion and scaling; the application still uses MSVC. In a developer PowerShell, run: