Update wiki for GNOME integration, OBS packaging, and architecture changes
- Adding-a-Desktop-Environment: replace scaffold GNOME code with actual
implementation (GnomeDesktop, LinuxDesktopBase, Shell extension, D-Bus
callback, desktop factory), add Hyprland guide as next-DE example
- Architecture: add LinuxDesktopBase to class hierarchy, add GNOME focus
tracking sequence diagram, update command ordering (settings before
button diversions, queue flush)
- Building: add gnome-extension and pkg/obs to project structure, update
CI section for multi-distro matrix, add OBS packaging docs
- Getting-Started: add OBS repo install instructions for Ubuntu/Fedora,
add GNOME-specific first-run notes (extension auto-install, Shell restart)
- Home: add GNOME 42+ to supported DE table
- Testing: add test_desktop_factory.cpp to test index