Fix: Not to render on display with HEADLESS

dotfiles/.config/quickshell/shell.qml

@@ -4,7 +4,11 @@ import "./modules/osd"
 
 ShellRoot {
     Variants {
-        model: Quickshell.screens
+        // Exclude the Sunshine headless virtual monitor — nobody ever sees a
+        // bar there, but PanelWindow's exclusiveZone still reserves space for
+        // it, which left a black strip cut out of Steam Big Picture's
+        // fullscreen area on that output.
+        model: Quickshell.screens.filter(s => !s.name.startsWith("HEADLESS"))
 
         Bar {
             required property var modelData