Feature: Add MCP (Model Context Protocol) server integration

Add an optional MCP server (JSON-RPC 2.0 over Streamable HTTP) exposing
an online-host listing tool, protected by a Bearer token. Disabled by
default; configured via a new "Extensions > MCP Settings" dialog.

- McpServer: httplib + JSON-RPC 2.0 dispatch (initialize/ping/tools/list/tools/call)
- McpSettingsDlg: runtime-created dialog for enable/port/bind/token
- HostJson: extract single-host JSON serialization shared with WebService
- FRP: expose MCP port (union with listening/Web ports) when bound to 0.0.0.0
- i18n: en_US / zh_TW translations

Co-Authored-By: deepseek-v4-pro

server/2015Remote/UIBranding.h

@@ -171,6 +171,7 @@
 #define HIDE_MENU_RELOAD_PLUGINS        0   // 重新加载插件
 #define HIDE_MENU_PLUGIN_REQUEST        0   // 插件请求
 #define HIDE_MENU_FRPS_FOR_SUB          0   // 下级FRP
+#define HIDE_MENU_MCP_SETTINGS          0   // MCP设置
 
 // --- 扩展菜单 - 语言子菜单 ---
 #define HIDE_MENU_CHANGE_LANG           0   // 更改语言
@@ -298,6 +299,8 @@
 // 用的 master password 解耦——后者一旦泄漏影响面更大，应避免在公网登录
 // 时复用。与 Go 服务端的 YAMA_WEB_ADMIN_PASS 语义一致。
 #define BRAND_WEB_ENV_VAR       "YAMA_WEB_ADMIN_PASS"
+// MCP 服务端静态 token 环境变量（优先级高于 settings/McpToken）
+#define BRAND_MCP_ENV_VAR       "YAMA_MCP_TOKEN"
 
 // --- 宽字符版本（自动生成）---
 #define BRAND_APP_NAME_W        _T(BRAND_APP_NAME)