The global 'dpy' variable was set to the XWayland Display*, causing
120+ direct Xlib calls in the WM core (XMapWindow, XClearWindow, etc.)
to pass synthetic frame buffer IDs to XWayland — hanging the startup.
Fix: wl_display_open returns NULL so global dpy=NULL. All existing
'if (dpy)' guards in the WM core now correctly skip Xlib calls.
The Wayland backend uses wl_state.x_display directly for the few
XWayland operations it needs (atom interning, screen info, GC alloc
for the no-focus window).
This unblocks startup — the event loop now runs successfully.
Levi Neely