fix: address review feedback on warning infrastructure

- Separate ParameterErrorCode::NONE from error cases in
  classify_error_code with comment explaining it is unreachable
- Add comment to ros2_medkit_msgs explaining why ROS2MedkitWarnings
  is not included (rosidl-generated code)
- Simplify format specifier in fault_manager_node: use %ld directly
  instead of PRId64 + static_cast (declare_parameter<int> returns long)

Author: bburda

src/ros2_medkit_fault_manager/src/fault_manager_node.cpp

@@ -17,7 +17,6 @@
 #include <yaml-cpp/yaml.h>
 
 #include <cctype>
-#include <cinttypes>
 #include <filesystem>
 #include <fstream>
 #include <nlohmann/json.hpp>
@@ -111,8 +110,7 @@ FaultManagerNode::FaultManagerNode(const rclcpp::NodeOptions & options) : Node("
   }
   auto max_snapshots = declare_parameter<int>("snapshots.max_per_fault", 10);
   if (max_snapshots < 0) {
-    RCLCPP_WARN(get_logger(), "snapshots.max_per_fault should be >= 0, got %" PRId64 ". Disabling limit.",
-                static_cast<int64_t>(max_snapshots));
+    RCLCPP_WARN(get_logger(), "snapshots.max_per_fault should be >= 0, got %ld. Disabling limit.", max_snapshots);
     max_snapshots = 0;
   }
 

src/ros2_medkit_gateway/src/http/handlers/config_handlers.cpp

@@ -134,6 +134,11 @@ static ErrorClassification classify_error_code(ParameterErrorCode error_code) {
       result.error_code = ERR_INVALID_PARAMETER;
       break;
     case ParameterErrorCode::NONE:
+      // NONE means "no error" - caller (classify_parameter_error) pre-filters
+      // this case, so reaching here indicates a programming error.
+      result.status_code = 500;
+      result.error_code = ERR_INTERNAL_ERROR;
+      break;
     case ParameterErrorCode::SHUT_DOWN:
     case ParameterErrorCode::INTERNAL_ERROR:
     default:

src/ros2_medkit_msgs/CMakeLists.txt

@@ -15,6 +15,8 @@
 cmake_minimum_required(VERSION 3.8)
 project(ros2_medkit_msgs)
 
+# Note: ROS2MedkitWarnings is intentionally NOT included here.
+# rosidl-generated code triggers strict warnings we cannot fix.
 find_package(ament_cmake REQUIRED)
 find_package(rosidl_default_generators REQUIRED)
 find_package(builtin_interfaces REQUIRED)