feat(quickshell): add ScreenCorners widget modified from end-4

modules/quickshell/config/Widgets/ScreenCorners/ScreenCorners.qml

@@ -0,0 +1,49 @@
+import QtQuick
+import QtQuick.Controls
+import Quickshell
+import Quickshell.Wayland
+
+import "../../Components/RoundCorner"
+
+Scope {
+    id: screenCorners
+
+    readonly property Toplevel activeWindow: ToplevelManager.activeToplevel
+
+    Variants {
+        model: Quickshell.screens
+
+        PanelWindow {
+            property var modelData
+
+            WlrLayershell.layer: WlrLayer.Overlay
+            WlrLayershell.namespace: "quickshell:screenCorners"
+            color: "transparent"
+            exclusionMode: ExclusionMode.Normal
+            margins.bottom: -1
+            screen: modelData
+
+            mask: Region {
+                item: null
+            }
+
+            anchors {
+                bottom: true
+                left: true
+                right: true
+            }
+
+            RoundCorner {
+                anchors.bottom: parent.bottom
+                anchors.left: parent.left
+                corner: RoundCorner.Corner.BottomLeft
+            }
+
+            RoundCorner {
+                anchors.bottom: parent.bottom
+                anchors.right: parent.right
+                corner: RoundCorner.Corner.BottomRight
+            }
+        }
+    }
+}