Add TetraIF targets to GROUP6 and create compilation tests

- Add CoPrtCnv, PrtCnvLib, PrtCnv to GROUP6_TARGETS in new_docker_build.sh
- Clean up redundant find_package(Qt6) in CoPrtCnv/CMakeLists.txt
- Add CTest compilation tests for CoPrtCnv, LogView, and PrtCnv headers
- Tests verify Qt6/C++17 compatibility of TetraIF module headers

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

qt6-after/qt6-migrated-legatus/tests/test_tetraif_prtcnv.cpp

@@ -0,0 +1,33 @@
+/**
+ * @file test_tetraif_prtcnv.cpp
+ * @brief Compilation test for TetraIF/PrtCnv headers
+ *
+ * This test verifies that the migrated PrtCnv headers compile correctly with Qt6/C++17.
+ */
+
+#include "TetraIF/PrtCnv/PrtCnvStoredTelegram.hpp"
+#include "TetraIF/PrtCnv/PrtCnvInjectionSocket.hpp"
+#include "TetraIF/PrtCnv/PrtCnvMember.hpp"
+#include "TetraIF/PrtCnv/PrtCnvThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvBroadcastMgr.hpp"
+#include "TetraIF/PrtCnv/PrtCnvApplication.hpp"
+#include "TetraIF/PrtCnv/PrtCnvRadioTrafficThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvInjectionThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvSocketThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvThreadStarter.hpp"
+#include "TetraIF/PrtCnv/IAppComponent.hpp"
+#include "TetraIF/PrtCnv/PrtCnvDbThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvTelegramLogThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvRadioThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvCentralThread.hpp"
+#include "TetraIF/PrtCnv/PrtCnvStoredRadioTelegram.hpp"
+#include "TetraIF/PrtCnv/PrtCnvStoredCentralTelegram.hpp"
+#include "TetraIF/PrtCnv/AppComponent.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(TetraIF_PrtCnv, HeadersCompile)
+{
+    // This test verifies that the PrtCnv headers compile without errors
+    EXPECT_TRUE(true);
+}