Qt6 Migration: Complete migration with DDS/RTI support and build validation

Major Changes:
- Merged latest Qt5 devel content from dlbo (292 files changed, 7 new dirs)
- Consolidated forward-declarations and include folders
- Removed unneeded modules per Niklas' repo check list

Build System Fixes:
- Fixed CMake VERSION_GREATER syntax in ParticipantManagement/CMakeLists.txt
- Added VLC packages (libvlc-dev, vlc-plugin-base) to docker_build.sh
- Added PostgreSQL dev packages (libpq-dev, postgresql-server-dev-all) to Dockerfile
- Fixed locale warnings (ANSI_X3.4-1968 → C.UTF-8)
- Fixed ArcGIS SDK path warnings when BUILD_ARCGIS=OFF

Code Generation Fixes:
- Fixed IDL enum collisions (PortType→CorePortType/DdsutPortType, PdmEventType)
- Fixed Grantlee template svc_translation.cpp.grantlee:
  - Changed {{ idl_enum.name }}_def:: to {{ idl_enum.name }}::
  - Fixed .underlying() calls for C++11 scoped enums (enum class)
- Removed generated files from repo (moc_*, *_dtc.h, *_ftc.h)

Validation:
- BUILD_RTI=ON: SUCCESS
- BUILD_RTI=OFF: SUCCESS
- C++17 standard maintained for RTI 7.7 compatibility
- Ubuntu 26.04 Docker environment verified

Remaining Warnings (expected):
- BgViewer, KDChart, KDReports, Poppler-Qt6 not found (optional features)

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

qt5-before/dlbo/Lts/Common/LtsAppManager/AppChooser/app_chooser.cpp

@@ -0,0 +1,93 @@
+// TODO: hdr
+
+#include "AppChooser/app_chooser.h"
+#include "ui_app_chooser.h"
+#include "AppChooser/app_chooser_model.h"
+#include "lts_app_manager.h"
+#include "AppChooser/CustomViews/app.h"
+
+#include <QCloseEvent>
+
+#include <QDebug>
+
+
+namespace LtsAppManager
+{
+
+AppChooser::AppChooser()
+  : QWidget(nullptr)
+  , m_ui(new Ui::AppChooser)
+  , m_model()
+  , m_madeSelection(false)
+{
+  m_ui->setupUi(this);
+  setAttribute(Qt::WA_DeleteOnClose); // delete when closed
+
+  connect(m_ui->widget, &LtsDataView::LtsDataView::LtsDataView::signalDoubleClicked,
+          this, &AppChooser::slotAppSelected);
+  connect(m_ui->widget, &LtsDataView::LtsDataView::LtsDataView::signalEnterPressed,
+          this, &AppChooser::slotAppSelected);
+  connect(m_ui->widget, &LtsDataView::LtsDataView::LtsDataView::signalSelectionChanged,
+          this, &AppChooser::enaDisa);
+  connect(m_ui->pbQuit, &QPushButton::clicked,
+          this, &QWidget::close); // calls closeEvent
+  connect(m_ui->pbSelect, &QPushButton::clicked,
+          this, &AppChooser::slotAppSelected);
+
+  m_model = new AppChooserModel(this);
+  m_model->initModel(LtsAppManager::getInstance()->getAvailableApps()); // TODO: test return val?
+
+  m_ui->widget->seamless();
+  //m_ui->widget->selectCustomView();
+  m_ui->widget->setModel(m_model);//, [&]() { return new CustomViewApp(this); });
+  m_ui->widget->hideColumn(AppChooserModel::Columns::Visible);
+}
+
+
+AppChooser::~AppChooser()
+{
+//  qCritical() << "~AppChooser";
+  delete m_ui;
+}
+
+
+void AppChooser::slotQuit()
+{
+  if (m_alreadyCloseEmitted)
+    return;
+  m_alreadyCloseEmitted = true;
+  emit signalLogout(); // if this window closes and no selection was made, then logout! (no apps, no login)
+}
+
+
+void AppChooser::closeEvent(QCloseEvent */*event*/)
+{
+  if (!m_madeSelection)
+    slotQuit();
+}
+
+
+void AppChooser::slotAppSelected()
+{
+  const QModelIndex idx = m_ui->widget->currentIndex();
+  const LtsAppDescriptor::AppDescription app = m_model->getRowData(idx.row());
+
+  if (!app.active)
+    return;
+
+  hide();
+  m_madeSelection = true;
+  emit signalAppSelected(app.id);
+  close();
+}
+
+
+void AppChooser::enaDisa()
+{
+  const QModelIndexList selectedRows = m_ui->widget->selectedRows();
+  const int cntSelectedRows = selectedRows.size();
+
+  m_ui->pbSelect->setEnabled(cntSelectedRows == 1);
+}
+
+} // namespace LtsAppManager