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/EffectShowManagement/handler_ppm_data.h

@@ -43,7 +43,7 @@ public:
     Participant_t() = default;
     explicit Participant_t(const ParticipantManagement::Participant &data)
       : id(data.id)
-      , equipmentNumber(data.equipmentNumber.is_set() ? data.equipmentNumber.get() : 0)
+      , equipmentNumber(data.equipmentNumber.has_value() ? data.equipmentNumber.get() : 0)
       , name(QString::fromStdString(data.name))
     {}