feat(rdp): enhance RDP client selection and connection handling

- Added options for selecting between built-in RDP and Windows Remote Desktop in the settings and connection menus.
- Updated connection handling to respect user preferences for RDP client mode during connection attempts.
- Introduced context menu actions for opening RDP connections with specified client modes.
- Enhanced documentation for RDP session types to clarify client selection behavior.
- Added tests to ensure correct behavior of RDP client mode selection and connection handling across different platforms.

docs-site/docs/guide/session-types.md

@@ -107,6 +107,12 @@ Telnet 会话适合：
 
 ## RDP
 
+Windows 桌面端可以在 **设置 → 连接 → 远程桌面** 中选择默认 RDP 客户端，初始为 NyaTerm 内置 RDP。在新建或编辑 RDP 连接时，“打开方式”可以跟随默认设置，也可以单独选择内置 RDP 或 Windows 远程桌面。已有连接会继续跟随原来的全局偏好。
+
+已保存的 RDP 连接右键菜单还提供“使用内置 RDP 打开”和“使用 Windows 远程桌面打开”，仅影响当前连接的本次打开，不修改默认设置或保存的连接。批量连接按每个连接的偏好打开。
+
+Windows 远程桌面使用系统独立窗口，仅接收地址和端口；用户名、密码、域、代理、SSH 跳板机及其他参数由系统客户端管理。NyaTerm 中保存的参数仍可用于内置 RDP。已存在的内置会话重连、分屏和启动恢复继续使用内置客户端；非 Windows 桌面端使用内置 RDP，Web 不提供 RDP。
+
 RDP 会话适合连接 Windows 主机或提供 RDP 服务的远程桌面环境。它和终端会话共享同一套标签页、分屏和保存连接体系，但底层是图形远程桌面，而不是文本终端。
 
 创建 RDP 会话时可以配置：

docs-site/i18n/en/docusaurus-plugin-content-docs/current/guide/session-types.md

@@ -105,6 +105,12 @@ Serial sessions still live inside NyaTerm's tabbed and split workspace, so you c
 
 ## RDP
 
+On Windows desktop, choose the default RDP client in **Settings → Connections → Remote Desktop**. The initial default is NyaTerm built-in RDP. When creating or editing an RDP connection, **Open with** can follow the default or select either built-in RDP or Windows Remote Desktop. Existing connections continue to follow your previous global preference.
+
+The saved RDP connection context menu also offers **Open with built-in RDP** and **Open with Windows Remote Desktop**. These actions apply only to that connection's current launch and do not change saved preferences, even with multiple connections selected. Batch launches use each connection's preference.
+
+Windows Remote Desktop opens in a separate system window and receives only the address and port. Credentials, domain, proxies, SSH jump hosts, and other options are managed by the system client. Parameters saved in NyaTerm remain available for built-in RDP. Existing built-in sessions keep using built-in RDP for reconnects, splits, and startup restoration. Other desktop platforms use built-in RDP; Web does not offer RDP.
+
 RDP sessions are for Windows hosts or other environments that expose a Remote Desktop endpoint. They share NyaTerm's saved-connection, tab, and split-pane workspace model, but the underlying session is a graphical desktop instead of a text terminal.
 
 When creating an RDP session, you can configure: