Implement 40250 classic client port

CMakeLists.txt

@@ -21,6 +21,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 option(MTGODOT_BUILD_EXTENSION "Build the Godot GDExtension (pulls in godot-cpp)" ON)
 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)
 
 # --- shared, cross-platform core (no godot-cpp, no third-party) ---
 add_subdirectory(libgr2)
@@ -46,3 +47,27 @@ if(MTGODOT_BUILD_EXTENSION)
     endif()
     add_subdirectory(extension)
 endif()
+
+# FreeBSD is the native build target of the archived 40250 server, but it is
+# not a supported Godot extension target.  Keep the live classic probe
+# available as a small host-only build so a FreeBSD jail/VM can compile and run
+# it without pulling in godot-cpp or the Darwin/iOS/Android extension.
+if(MTGODOT_BUILD_NET_TOOLS AND NOT MTGODOT_BUILD_EXTENSION)
+    add_subdirectory(extension/third_party)
+    add_library(mtnet_host STATIC
+        extension/src/net/secure_cipher.cpp
+        extension/src/net/net_stream.cpp
+        extension/src/net/entity_store.cpp
+        extension/src/net/mark_image.cpp
+        extension/src/net/classic/classic_stream.cpp
+        extension/src/net/classic/classic_parser.cpp
+        extension/src/net/classic/classic_session.cpp
+        extension/src/net/classic/classic_cipher.cpp
+    )
+    target_include_directories(mtnet_host PUBLIC extension/src/net)
+    target_link_libraries(mtnet_host PUBLIC mt3p::sodium mt3p::minilzo mt3p::cryptopp)
+    target_compile_features(mtnet_host PUBLIC cxx_std_20)
+
+    add_executable(net_classic_e2e_host extension/tools/net_classic_e2e.cpp)
+    target_link_libraries(net_classic_e2e_host PRIVATE mtnet_host)
+endif()