feat: complete native client rendering parity updates

CMakeLists.txt

@@ -23,6 +23,7 @@ option(MTGODOT_BUILD_EXTENSION "Build the Godot GDExtension (pulls in godot-cpp)
 option(MTGODOT_BUILD_TOOLS     "Build libgr2 validation tools (gr2dump/gr2fuzz/oracle_diff)" OFF)
 option(MTGODOT_BUILD_NET_TOOLS "Build host-only protocol probes without Godot" OFF)
 option(MTGODOT_BUILD_PORT      "Build only port_logic (with MTGODOT_BUILD_EXTENSION=OFF), e.g. for Linux/Windows" OFF)
+option(MT_BUILD_NATIVE_RENDER_PROTOTYPE "Build the standalone Vulkan draw-command prototype" OFF)
 
 # --- shared, cross-platform core (no godot-cpp, no third-party) ---
 add_subdirectory(libgr2)
@@ -81,3 +82,7 @@ if(MTGODOT_BUILD_PORT AND NOT MTGODOT_BUILD_EXTENSION)
     endif()
     add_subdirectory(extension/src/port)
 endif()
+
+if(MT_BUILD_NATIVE_RENDER_PROTOTYPE)
+    add_subdirectory(native_render)
+endif()