Qt6 migration, custom icons, UI enhancements, and simulation improvements

- Migrate entire codebase from Qt5 to Qt6 (Core5Compat for QTextCodec)
- Add Material Symbols icon provider with dark mode auto-detection
- Add custom SVG app icons for client and server
- Set default tabbed view mode, update about page credits
- Add dark-mode-aware status column colors in client dataview
- Add drag-and-drop from dataview/device view to simulation actions
- Add right-click context menu to add simulation actions from dataview
- Fix simulation action enable/disable and runtime editing
- Fix simulation value updates in UI during runtime
- Update .gitignore for build artifacts and packaging output
- Update documentation logos to SVG format

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: QuakeString

.gitignore

@@ -13,3 +13,14 @@ TODO
 __pycache__/
 *.py[cod]
 *$py.class
+
+# Build directories
+build/
+build-*/
+CMakeFiles/
+
+# Packaging artifacts
+packaging/arch/*.pkg.tar.zst
+packaging/arch/pkg/
+packaging/arch/src/
+dist/

CMakeLists.txt

@@ -1,8 +1,11 @@
-cmake_minimum_required(VERSION 3.13) # 2.2 - case insensitive syntax
+cmake_minimum_required(VERSION 3.16) # Qt6 requires 3.16+
                                      # 3.13 included policy CMP0077
 
 project(ModbusTools VERSION 0.4.9 LANGUAGES CXX)
 
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 set(MBTOOLS_VERSION ${PROJECT_VERSION})
 set(MBTOOLS_ROOT_DIR ${CMAKE_SOURCE_DIR})