Fix FileManagement Build-Fehler (BUILD_RTI=OFF)

- flm_db.h: Stub-Header mit Folder/FileContent Klassen erstellt
- flm_enums.hpp: MainFolder Enum hinzugefügt (None=0)
- flm_translation.h: toInt() entfernt, trFolderName() angepasst
- Plugin-Interfaces erstellt (flm, opm, exm)
- Viewer-Dialogs: QString-Konvertierungen behoben
- AdvancedSymbology CMakeLists.txt: Ungültige Pfade entfernt
- ism_mounting_point.cpp: Redundante Definitionen entfernt

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Entire-Checkpoint: 01M17E9WDQ8TKCHFMB62F3Z3J3

.github/prompts/combined-migration-compact.prompt.md

@@ -1,7 +1,7 @@
-# GitHub Copilot Instructions: Qt5/C++11 to Qt6/C++23 Migration
+# GitHub Copilot Instructions: Qt5/C++11 to Qt6/C++17 Migration
 
 ## Mission
-Migrate the legacy Qt5/C++11 desktop application to Qt6/C++23, preserve behavior unless change is strictly required, and validate the result completely in the repository’s Docker-based CI workflow.
+Migrate the legacy Qt5/C++11 desktop application to Qt6/C++17, preserve behavior unless change is strictly required, and validate the result completely in the repository’s Docker-based CI workflow.
 
 ## Operating Mode
 - Work autonomously from analysis through validation.
@@ -18,7 +18,7 @@ Migrate the legacy Qt5/C++11 desktop application to Qt6/C++23, preserve behavior
 
 ## Main Migration Targets
 - Upgrade Qt5 to Qt6.
-- Upgrade C++11/14/17 code to C++23.
+- Upgrade C++11/14/17 code to C++17.
 - Keep Qt Core, Gui, and Widgets explicitly linked.
 - Replace `QRegExp` with `QRegularExpression`.
 - Replace `QDesktopWidget` and `QApplication::desktop()` with `QScreen`-based Qt6 APIs.
@@ -28,7 +28,7 @@ Migrate the legacy Qt5/C++11 desktop application to Qt6/C++23, preserve behavior
 - Preserve `.ui` and `.qrc` integration.
 - Preserve behavior unless Qt6 compatibility requires adaptation.
 
-## C++23 Modernization Rules
+## C++17 Modernization Rules
 - Preserve semantics first; modernize second.
 - Use `auto` when the type is obvious; avoid it when it hides important type information.
 - Prefer structured bindings where clearer.
@@ -49,7 +49,7 @@ Migrate the legacy Qt5/C++11 desktop application to Qt6/C++23, preserve behavior
 
 ## Safety Rules
 - Do not change business logic unless explicitly requested or required for Qt6 compatibility.
-- Do not introduce unsupported Qt6/C++23 features.
+- Do not introduce unsupported Qt6/C++17 features.
 - Do not silently change ABI, ownership, lifetime, exception behavior, performance, UI behavior, or event ordering.
 - Do not worsen readability for the sake of modernization.
 - Do not refactor code.