Put the first click after crossing onto a screen where the pointer is

KWin's nested backend ignores the position in wl_pointer.enter, and
wlroots drops a motion to the position it entered at, so KWin kept its old
pointer until the next move.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

screens/compositor.c

@@ -272,7 +272,12 @@ static void handle_vr_event(const struct ft_event *e, void *data) {
         case FT_MOTION:
         case FT_BUTTON:
             if (s->pointer_focus != sc) {
-                wlr_seat_pointer_notify_enter(s->seat, surface, x, y);
+                // KWin's nested backend ignores the position in wl_pointer.enter, and wlroots
+                // drops a motion to the position it entered at, so KWin would keep its old
+                // pointer until the next move: a press right after crossing onto another
+                // screen landed where the pointer had been. Entering one unit off makes the
+                // motion below go through.
+                wlr_seat_pointer_notify_enter(s->seat, surface, x + 1, y);
                 s->pointer_focus = sc;
             }
             wlr_seat_pointer_notify_motion(s->seat, t, x, y);