[feat] display video codecs and refine network statistics

docs/USER_GUIDE.md

@@ -95,13 +95,15 @@ sudo apt install "./crossdesk-virtual-desktop-xfce-linux-amd64-<version>.deb"
 | 扬声器 | 播放声音 / 静音 |
 | 文件夹 | 选择文件发送到远端，并查看传输进度 |
 | 画面设置 | 在当前会话中调整画面质量、采集帧率与画面偏好 |
-| 网络状态 | 查看流量、丢包率、帧率、分辨率、直连 / 中继及加密状态 |
+| 网络状态 | 查看流量、丢包率、帧率、分辨率、直连 / 中继、加密状态，以及被控端编码器和控制端解码器 |
 | 隐私屏 | 开启或关闭被控电脑的隐私屏；悬停查看当前状态与可用操作 |
 | 全屏 | 进入 / 退出全屏 |
 | 断开连接 | 结束当前远程会话 |
 
 桌面端可同步文本剪贴板。接收文件的位置可在“设置 → 常规 → 文件保存路径”调整。关闭主窗口会隐藏窗口并保持程序运行；需要完全退出时使用系统托盘或菜单栏中的退出入口。
 
+普通会话与桌面墙的网络状态均显示实际使用的视频编解码器名称，包括回退后的软件编解码器。名称统一采用“实现名称 (编码格式)”，名称首字母大写、技术缩写保留全大写，例如 `VideoToolbox (H.264)`、`NVENC (H.264)`、`NVDEC (H.264)`、`SVT-AV1 (AV1)`、`Dav1d (AV1)` 和 `LibAOM (AV1)`；Media Foundation 额外标注 `HW`（硬件）或 `SW`（软件）。被控端需要支持编码器状态上报；旧版本或尚未获取到的信息显示“—”。
+
 ### 在会话中调整画面
 
 连接成功后，点击工具栏中的 **画面设置**（滑杆图标），直接选择低 / 中 / 高画质、**30 / 60 fps**，以及帧率优先 / 画质优先 / 平衡。选项会发送给当前被控端，无需断开重连；实际画面效果取决于网络、设备与编码器能力。旧版被控端不支持时，菜单会提示并禁用选项。

docs/USER_GUIDE_EN.md

@@ -95,13 +95,15 @@ Switch devices using session tabs. Expand the control bar if it is collapsed, an
 | Speaker | Play / mute remote audio |
 | Folder | Select a file to send and view transfer progress |
 | Video settings | Adjust video quality, capture frame rate, and video preference during the current session |
-| Network statistics | Inspect traffic, packet loss, frame rate, resolution, direct / relay mode, and encryption status |
+| Network statistics | Inspect traffic, packet loss, frame rate, resolution, direct / relay mode, encryption status, the remote encoder, and the local decoder |
 | Privacy screen | Enable or disable the host's privacy screen; hover to see its status and available actions |
 | Fullscreen | Enter / exit fullscreen |
 | Disconnect | End the current remote session |
 
 Desktop clients synchronize text clipboard contents. Configure the receiving directory under **Settings → General → File Save Path**. Closing the main window hides it and keeps the app running; use the system tray or menu-bar exit command to quit completely.
 
+Network statistics in both ordinary sessions and DeskHub show the video codecs actually in use, including software fallback. Names use “Implementation (Format)” with an initial capital and uppercase technical abbreviations, such as `VideoToolbox (H.264)`, `NVENC (H.264)`, `NVDEC (H.264)`, `SVT-AV1 (AV1)`, `Dav1d (AV1)`, and `LibAOM (AV1)`; Media Foundation also includes `HW` (hardware) or `SW` (software). The host must support encoder status reporting; older versions and information not yet available display “—”.
+
 ### Adjust video during a session
 
 After connecting, open **Video settings** (the sliders icon) in the toolbar. Choose low / medium / high quality, **30 / 60 fps**, and frame-rate priority / quality priority / balanced adaptation. Changes are sent to the current host without reconnecting; actual results depend on the network, device, and encoder. For older hosts that do not support live video settings, the menu explains the limitation and disables the options.