Complete Qt6 migration: full clean build green across groups G1-G12 incl. runtime plugin set

new_docker_build.sh gains Group 12 (212 GUI/Data plugins); fixes LtsUtilsGuiDds visibility (LTO-stripped exports), LtsProjectionWorkstation unity name shadow, 6 unity-off dirs (dup file-scope statics, ddsftc INTERFACE sources) and reconfigures BUILD_FILTERMANAGEMENT/BUILD_PLUGINS_SERVICEMONITOR=ON

qt6-after/qt6-migrated-legatus/Lts/Services/EffectShowClient/handler_firing_explosion.cpp

@@ -59,7 +59,7 @@ bool HandlerFiringExplosion::init()
 //=============================================================================
 void HandlerFiringExplosion::setFiringClearanceDuration()
 {
-  if (m_firingExplosionEntity.firingClearanceTime.is_set())
+  if (m_firingExplosionEntity.firingClearanceTime.has_value())
   {
     qint64 pre = m_firingExplosionEntity.firingClearanceTime.get();
     qint64 post = pre;