Integrate Paho MQTT C library into project. Updated CMakeLists.txt to find PahoMqttC package and added fallback for manual linking. Refactored mqtt.hpp and mqtt.cpp to utilize Paho MQTT C API, replacing previous async client implementation. Added Windows setup guide for MQTT library installation.

CMakeLists.txt

@@ -9,13 +9,21 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 find_package(PkgConfig REQUIRED)
 find_package(Threads REQUIRED)
 
-# Find installed unitree_sdk2
+# Try to find PahoMqttC, fallback to manual linking if not found
+find_package(PahoMqttC QUIET)
+if(NOT PahoMqttC_FOUND)
+    message(STATUS "PahoMqttC package not found, using manual library linking")
+    find_library(PAHO_MQTT_C_LIBRARY NAMES paho-mqtt3c REQUIRED)
+    find_path(PAHO_MQTT_C_INCLUDE_DIR NAMES MQTTClient.h REQUIRED)
+endif()
+
 find_package(unitree_sdk2 REQUIRED)
 
 # Include directories
 include_directories(
     ${CMAKE_CURRENT_SOURCE_DIR}/include
     ${CMAKE_CURRENT_SOURCE_DIR}/include/nlohmann
+    $<$<NOT:$<BOOL:${PahoMqttC_FOUND}>>:${PAHO_MQTT_C_INCLUDE_DIR}>
 )
 
 # Source files
@@ -25,7 +33,7 @@ set(SOURCES
     src/custom_robot.cpp
     src/config.cpp
     src/logger.cpp
-    # src/mqtt.cpp  # Disabled MQTT for now
+    src/mqtt.cpp
 )
 
 # Create executable with simple name
@@ -35,6 +43,8 @@ add_executable(main ${SOURCES})
 target_link_libraries(main
     unitree_sdk2
     Threads::Threads
+    $<$<BOOL:${PahoMqttC_FOUND}>:PahoMqttC::PahoMqttC>
+    $<$<NOT:$<BOOL:${PahoMqttC_FOUND}>>:${PAHO_MQTT_C_LIBRARY}>
 )
 
 # Set output directory