Feature: Linux/macOS server-identity gate via libsign.a

fix remote-cursor flicker on Windows controller

linux/CMakeLists.txt

@@ -28,6 +28,7 @@ set(SOURCES
     main.cpp
     ../client/Buffer.cpp
     ../client/IOCPClient.cpp
+    ../client/sign_shim_unix.cpp
 )
 add_executable(ghost ${SOURCES})
 
@@ -40,6 +41,14 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g")
 message(STATUS "链接库文件: ${CMAKE_SOURCE_DIR}/lib/libzstd.a")
 target_link_libraries(ghost PRIVATE "${CMAKE_SOURCE_DIR}/lib/libzstd.a")
 
+# 链接私有签名库（提供 signMessage / verifyMessage，源码不开源）
+# 该库由 SimplePlugins 仓库本地构建后放置于 lib/，构建机需先准备好
+target_link_libraries(ghost PRIVATE "${CMAKE_SOURCE_DIR}/lib/libsign.a")
+
+# libsign.a 内部使用 OpenSSL HMAC，需要在最终可执行链接 libcrypto
+find_package(OpenSSL REQUIRED)
+target_link_libraries(ghost PRIVATE OpenSSL::Crypto)
+
 # 链接 dl 库（dlopen/dlsym 用于运行时加载 X11）
 target_link_libraries(ghost PRIVATE dl)