Linux X11

X11 is the supported moving-window platform. The adapter connects through DISPLAY, reads EWMH properties, enumerates client windows, filters ineligible windows, reads frame extents, restores minimized windows, and sends move/resize requests.

The screen work area comes from _NET_WORKAREA when available. The current implementation reports XRandR as unavailable and does not implement native multi-monitor XRandR arrangement. Window-manager support and EWMH capability are visible in System Status.

If an X11 display is unavailable, Grid Screen falls back to a mock adapter with an error rather than silently claiming that arrangement works.