Qt6 migration: Fix BUILD_RTI=OFF build errors in TrainingAreaBase

- training_area_telegrams.cpp: Fixed QJsonObject initializer syntax (Qt6 requires {{}} not ({}))
- training_area_telegrams.cpp: Fixed fromJson() methods to access m_* members directly
- training_area_telegrams.cpp: Fixed brace mismatches in multiple toJson() methods
- training_area_telegrams.h: Changed Header struct to public members for consistency
- tx_mixin.cpp: Fixed getEquipmentNumber() template for direct member access
- lts_coordinate.cpp: Added missing #include <iomanip>
- MIGRATION_STATUS.md: Added migration progress tracking document

C++17 constraint enforced due to RTI Connext DDS 7.7.0 incompatibility with C++20+

Build status: BUILD_RTI=OFF successful (0 errors, warnings only)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

qt6-after/qt6-migrated-legatus/Lts/Services/AreaEffectSimulation/EffectorFiringStrategy/abstract_firing_strategy.cpp

@@ -18,7 +18,7 @@
 #include <LtsCoordTrans/lts_coord_trans.h>
 #include <LtsUtils/LtsUtilsCore/qpoint3d.h>
 
-#include <QJsonDocument>
+#include <QtCore/QJsonDocument>
 #include <QRandomGenerator>
 
 namespace AreaEffectSimulation

qt6-after/qt6-migrated-legatus/Lts/Services/AreaEffectSimulation/EffectorFiringStrategy/abstract_firing_strategy.h

@@ -21,9 +21,9 @@
 #pragma once
 
 #include <AreaEffectSimulation/logger.h>
-#include <QObject>
+#include <QtCore/QObject>
 #include <Core/core.hpp>
-#include <QJsonObject>
+#include <QtCore/QJsonObject>
 
 namespace Core
 {

qt6-after/qt6-migrated-legatus/Lts/Services/AreaEffectSimulation/EffectorFiringStrategy/dm72_firing_strategy.cpp

@@ -16,10 +16,10 @@
 #include <TrainingAreaBase/Plugins/AdlerJson/telegrams.h>
 #include <Trajectory/trajectory_transform.h>
 
-#include <QJsonArray>
-#include <QJsonDocument>
-#include <QJsonObject>
-#include <QJsonValue>
+#include <QtCore/QJsonArray>
+#include <QtCore/QJsonDocument>
+#include <QtCore/QJsonObject>
+#include <QtCore/QJsonValue>
 #include <QTransform>
 
 namespace AreaEffectSimulation

qt6-after/qt6-migrated-legatus/Lts/Services/AreaEffectSimulation/EffectorFiringStrategy/gmlrs_firing_strategy.cpp

@@ -14,8 +14,8 @@
 #include <Trajectory/trajectory_transform.h>
 #include <LtsCoordTrans/lts_coord_trans.h>
 
-#include <QJsonDocument>
-#include <QJsonObject>
+#include <QtCore/QJsonDocument>
+#include <QtCore/QJsonObject>
 
 namespace AreaEffectSimulation
 {

qt6-after/qt6-migrated-legatus/Lts/Services/AreaEffectSimulation/EffectorFiringStrategy/smart_firing_strategy.cpp

@@ -13,8 +13,8 @@
 #include <TrainingAreaBase/Plugins/AdlerJson/telegrams.h>
 #include <TrajectorySplitter/trajectory_splitter.h>
 
-#include <QJsonDocument>
-#include <QJsonObject>
+#include <QtCore/QJsonDocument>
+#include <QtCore/QJsonObject>
 
 namespace AreaEffectSimulation
 {