Fix Qt compatibility and VM script docs

Updates desktop shell and application code for cross-Qt compatibility: uses begin/endFilterChange for Qt 6.10+, gates LayerShell usage to Qt < 6.5, and adds include handling for generated QML type registration files so nebula-shell builds reliably. Also fixes qInfo size formatting casts and updates README commands to invoke run-sway-vm.sh via `sh` for more portable execution.

shells/desktop/shell/src/main.cpp

@@ -1,7 +1,5 @@
 #include "DesktopIconProvider.hpp"
 
-#include <LayerShellQt/Shell>
-
 #include <QCoreApplication>
 #include <QDir>
 #include <QGuiApplication>
@@ -11,6 +9,10 @@
 #include <QUrl>
 #include <QtGlobal>
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 5, 0)
+#include <LayerShellQt/Shell>
+#endif
+
 namespace {
 
 void initializeIconTheme()
@@ -45,7 +47,9 @@ void initializeIconTheme()
 
 int main(int argc, char *argv[])
 {
+#if QT_VERSION < QT_VERSION_CHECK(6, 5, 0)
     LayerShellQt::Shell::useLayerShell();
+#endif
 
     QGuiApplication app(argc, argv);
     app.setApplicationName(QStringLiteral("nebula-shell"));