MessageDispatcher.cpp

- Added MsgProtoUtils_h.jinja and MsgProtoUtils_cpp.jinja templates generating struct <-> protobuf conversion utilities (LeahiMsgProtoUtils.h/.cpp).

- Added write_msg_proto_utils_header/source to MsgCpp.py and a --proto flag path in GenerateMsgDefsCpp.py to produce the new files.

- Removed the proto flag from write_msg_defs_header/source and the MsgDefs templates so MsgDefs no longer embeds protobuf utilities.

- Updated MsgUtils.cmake to declare the MsgProtoUtils outputs and template dependencies, and CMakeLists.txt to list the generated files.

- Removed the obsolete ProtoInterface.h/cpp.

- Updated LeahiRtController to include LeahiMsgProtoUtils.h.

- Added MessageDispatcher to MsgUtils.

- Updated LeahiRt main.cpp signal handling to use signalfd + QSocketNotifier for graceful shutdown inside the event loop.

- Updated tools/CMakeLists.txt to build AgentSim.

- Updated AgentSimController::handleMessage to output received message protobuf to console.