Qt6 Migration: BUILD_RTI guards und CMake fixes

- BUILD_RTI conditional compilation für RTI Connext DDS dependencies
- Namespace fixes in core_dtc.h (Core:: → DDS::Core::)
- CMakeLists.txt: BUILD_RTI option und conditional dependencies
- Handler minelayer: namespace closing mit BUILD_RTI guard
- Build erfolgreich mit BUILD_RTI=OFF validiert

Signed-off-by: Torsten Wierschin <torsten.wierschin@life-maps.com>

qt6-after/qt6-migrated-legatus/Lts/Common/LtsTimelineClassic/TimelineIndicator.h

@@ -4,6 +4,7 @@
 #include "EventTools.h"
 #include "LineMap.h"
 
+#include <QComboBox>
 #include <QObject>
 #include <QPair>
 #include <QPoint>
@@ -16,15 +17,18 @@ class INGLLogger;
 }
 class QPushButton;
 class QLabel;
-class QComboBox;
 
 namespace LtsTimelineClassic
 {
 
+class TimelineIndicatorTest;
+
 class TimelineIndicator : public QWidget
 {
     Q_OBJECT
 
+    friend class TimelineIndicatorTest;
+
     static const int s_TimeTextDistanceTolerancePixels = 10;
     static const int s_pbSize = 18;
 
@@ -55,6 +59,10 @@ class TimelineIndicator : public QWidget
     NGL::INGLLogger& m_logger;
     void paintEvent(QPaintEvent*);
 
+  public:
+    // Public getter for testing
+    QComboBox* zoomLevelComboBox() const { return m_cbZoomLevel; }
+
   signals:
 
     void signalSetTimelineRange(qint64 min, qint64 max);