Remove every is_wayland / !is_wayland guard from WM policy files.
All backend-specific logic now lives exclusively in the backends:
- main.c: display_post_open vtable slot handles fatal check, visual ID,
display name, and multiHead parsing (X11) or no-ops (Wayland)
- event.c: EventLoop() unconditionally calls event_loop_run(); the X11
backend's implementation contains the WMNextEvent+inotify loop
- screen.c: screen_init_display vtable slot handles RContext/WMScreen/
color creation (each backend owns its full init path)
- monitor.c: show_crash_dialog vtable slot (X11 shows panel, Wayland
returns abort)
- startup.c: InitializeSwitchMenu called unconditionally (it's
backend-agnostic); defaults polling timer no longer guarded
- shutdown.c: wScreenSaveState called unconditionally
- window.c: client_reparent called unconditionally (Wayland no-ops);
dead frameless-window code removed
Policy code is now completely backend-agnostic. The only references to
is_wayland are the vtable field definitions in the two backend files.