BUILD_RTI conditional fixes and Qt6 API updates

- cmake/FindRTI.cmake: Add INTERFACE placeholder targets when RTI not found
- cmake/FindRTI.cmake: Force BUILD_RTI=OFF when RTI not installed
- Lts/Common/LtsSession/CMakeLists.txt: Make LtsSessionDataDds conditional on BUILD_RTI
- Lts/Viewer/CMakeLists.txt: Make LtsDataView conditional on BUILD_RTI
- Lts/Plugins/*/CMakeLists.txt: 97 plugin files wrapped in BUILD_RTI conditionals
- cmake/NGLMacros.cmake: Fix NGL_ADD_BIG_RESOURCES macro (removed premature return())
- Multiple Qt6 API fixes: QLinkedList→std::list, QStringRef→QStringView, etc.
- BUILD_RTI_FIXES_SUMMARY.md: Comprehensive documentation of all fixes

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

qt6-after/qt6-migrated-legatus/include/DDS/Core/core.hpp

@@ -0,0 +1,12 @@
+/**
+ * @file core.hpp
+ * @brief Core DDS Sammel-Header
+ * 
+ * Beinhaltet alle Core-Typen für DDS-Integration.
+ */
+
+#pragma once
+
+#include <Core/core_types.h>
+#include <Core/core_enums.hpp>
+#include <Core/core_dtc.h>

qt6-after/qt6-migrated-legatus/include/DDS/Core/core_dtc_types.h

@@ -0,0 +1,51 @@
+/**
+ * @file core_dtc_types.h
+ * @brief DDS-Stub für Core-Typen (DTC = Data Transfer Component)
+ * 
+ * Dieser Header enthält Stub-Definitionen für DDS-Core-Typen, die von RTI DDS generiert werden würden.
+ */
+
+#pragma once
+
+#include <QString>
+
+namespace IDL
+{
+
+enum class PartitionType
+{
+  Any = 0,
+  Live = 1,
+  Replay = 2,
+  Record = 3,
+  Gateway = 4
+};
+
+} // namespace IDL
+
+namespace Core
+{
+
+class ReplayPartition
+{
+public:
+  ReplayPartition() = default;
+  
+  int domainId() const { return m_domainId; }
+  int id() const { return m_id; }
+  int exerciseId() const { return m_exerciseId; }
+  QString tcpConnectionUrl() const { return m_tcpConnectionUrl; }
+  
+  void setDomainId(int id) { m_domainId = id; }
+  void setId(int id) { m_id = id; }
+  void setExerciseId(int id) { m_exerciseId = id; }
+  void setTcpConnectionUrl(const QString &url) { m_tcpConnectionUrl = url; }
+  
+private:
+  int m_domainId = -1;
+  int m_id = 0;
+  int m_exerciseId = 0;
+  QString m_tcpConnectionUrl;
+};
+
+} // namespace Core