Fix CMake build configuration for Windows64 platform

- Add #include <windows.h> to extraX64.h for Windows type definitions
- Remove duplicate byte typedef and suppress std::byte via _HAS_STD_BYTE=0
- Define _WINDOWS64 for correct platform header selection
- Set IGGY_LIBS to iggy_w64.lib for proper Iggy UI library linking

CMakeLists.txt

@@ -68,9 +68,14 @@ set(MINECRAFT_SHARED_DEFINES
   $<$<CONFIG:Debug>:_DEBUG>
   _CRT_NON_CONFORMING_SWPRINTFS
   _CRT_SECURE_NO_WARNINGS
+  _HAS_STD_BYTE=0
 )
 
 # Add platform-specific defines
+if(PLATFORM_NAME STREQUAL "Windows64")
+  list(APPEND MINECRAFT_SHARED_DEFINES _WINDOWS64)
+  set(IGGY_LIBS iggy_w64.lib)
+endif()
 list(APPEND MINECRAFT_SHARED_DEFINES ${PLATFORM_DEFINES})
 
 # ---

Minecraft.World/x64headers/extraX64.h

@@ -3,6 +3,7 @@
 #include <stdarg.h>
 #include <string>
 #include <functional>
+#include <windows.h>
 
 #include "..\..\Minecraft.Client\SkinBox.h"
 
@@ -11,7 +12,8 @@
 
 #define MULTITHREAD_ENABLE
 
-typedef unsigned char byte;
+// byte is already defined by rpcndr.h (via windows.h)
+// std::byte is suppressed via _HAS_STD_BYTE=0 in CMakeLists.txt
 
 const int XUSER_INDEX_ANY = 255;
 const int XUSER_INDEX_FOCUS = 254;