Feature: Add host management and connection management MCP tools

Expose the online-list TLS column through list_online_hosts, search_hosts
and get_host_detail. The value comes from the flag the client reports at
login, so old clients always read false.

Add list_network_connections and kill_network_connection on top of the
connection manager sub-connection protocol. The kill path matches the
original 110-byte record instead of rebuilding addresses, supports a dry
run, refuses UDP/IPv6 targets, and verifies that the quadruple really
disappeared instead of assuming success.

Add a host_* family backed by the machine manager protocol: ten read
tools covering every tab of the host management dialog, and four
recoverable write tools for process freeze/thaw, window restore/hide/
maximize/minimize, service start/stop/pause/continue/restart, and
scheduled task run/stop. Every write re-reads the snapshot before sending
and re-checks afterwards, reporting -32009 for stale targets rather than
acting blindly. The family is gated by McpMachine, the risky subset by
McpMachineDangerous, and writes additionally require read-only mode to
be off.

Route managed sub-connections from MessageHandle and OfflineProc, keep
the single-in-flight rule by sharing the pending table with a request
kind, and move the shared JSON/lock/encoding helpers into McpInternal so
both tool families use one implementation. Settings dialog, design docs
and en_US/zh_TW/de_DE translations are updated accordingly.

Co-Authored-By: deepseek-flash

server/2015Remote/McpSettingsDlg.h

@@ -32,6 +32,8 @@ private:
         IDC_MCP_REMOTECONTROL = 1008,  // 「启用远程控制」复选框（AI 操控桌面，要求只读关）
         IDC_MCP_FILETRANSFER = 1009,  // 「启用文件传输」复选框（download_file，不要求只读关）
         IDC_MCP_MANAGE      = 1010,  // 「启用管理操作」复选框（kill/窗口/服务/电源，要求只读关）
+        IDC_MCP_MACHINE     = 1011,  // 「启用主机管理」复选框（host_* 工具族）
+        IDC_MCP_MACHINE_DANGEROUS = 1012,  // 「启用危险主机操作」复选框（冻结/停止/重启）
     };
 
     CButton m_btnEnable;
@@ -42,6 +44,8 @@ private:
     CButton m_btnRemoteControl;
     CButton m_btnFileTransfer;
     CButton m_btnManage;
+    CButton m_btnMachine;
+    CButton m_btnMachineDangerous;
     CStatic m_lblWhitelist;
     CEdit   m_editWhitelist;
     CButton m_btnOK, m_btnCancel;