refactor: replace keybind toggle with config checkbox for skeleton visibility

Removes the pynput/curl-based shortcut approach in favour of a plain
Plasma wallpaper config checkbox (ShowSkeleton). QML reads the setting
on page load and on change, calling setShowSkeleton() in JS directly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugin/contents/ui/config.qml

@@ -0,0 +1,22 @@
+import QtQuick 2.15
+import QtQuick.Controls 2.15
+import QtQuick.Layouts 1.15
+import org.kde.kirigami 2.20 as Kirigami
+
+ColumnLayout {
+    id: root
+
+    property alias cfg_ShowSkeleton: skeletonCheck.checked
+
+    spacing: Kirigami.Units.largeSpacing
+
+    Kirigami.FormLayout {
+        Layout.fillWidth: true
+
+        CheckBox {
+            id: skeletonCheck
+            Kirigami.FormData.label: i18n("Esqueleto:")
+            text: i18n("Mostrar o robô dançando")
+        }
+    }
+}