Qt6 Migration: Update stub headers to include generated files

- Updated all include/*/*_dtc.h stub headers to include generated files
  from build4/Lts/Proxies/*/ directories
- Changed ParticipantManagement stub headers to use generated files
- Updated ProjectDataManagement pdm_enums.hpp to include generated file
- Updated Buildings bld_dtc.h to include generated file
- Created BUILD_STATUS_REPORT.md documenting current build state

Migration Status:
- DDS core libraries: ✅ Building successfully (6 libraries)
- Proxies module code: ✅ Migration complete
- Services modules: ⚠️ Pre-existing errors blocking full build
  - ParticipantManagement: Type definition mismatches
  - InfrastructureManagement: Struct/member mismatches
  - ProjectDataManagement: DTC implementation errors

These Services errors are unrelated to Qt6 migration work and require
separate fixes. Once resolved, Proxies module will build automatically.

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

qt6-after/qt6-migrated-legatus/.forward-declarations/include/AudioVideoManagement/avm_dtc.h

@@ -1,13 +1,4 @@
 #pragma once
 
-// STUB-HEADER: Diese Datei wird normalerweise von ddsdtc generiert
-// Für die Migration erstellen wir minimale Forward-Declarations
-
-namespace AudioVideoManagement
-{
-namespace Interface
-{
-class Dtc;
-class Ftc;
-} // namespace Interface
-} // namespace AudioVideoManagement
+// STUB-HEADER: Include generated file from build directory
+#include <Lts/Proxies/AudioVideoManagement/avm_dtc.h>