Advance Wayland and KDE package bring-up

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

local/recipes/kde/kf6-kwidgetsaddons/source/src/ksplittercollapserbutton.h

@@ -0,0 +1,78 @@
+/*
+    SPDX-FileCopyrightText: 2014 Montel Laurent <montel@kde.org>
+    based on code:
+    SPDX-FileCopyrightText: 2009 Aurélien Gâteau <agateau@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
+*/
+#ifndef KSPLITTERCOLLAPSERBUTTON_H
+#define KSPLITTERCOLLAPSERBUTTON_H
+
+// Qt
+#include <QToolButton>
+#include <kwidgetsaddons_export.h>
+#include <memory>
+
+class QSplitter;
+
+/**
+ * @class KSplitterCollapserButton ksplittercollapserbutton.h KSplitterCollapserButton
+ *
+ * A button which appears on the side of a splitter handle and allows easy
+ * collapsing of the widget on the opposite side
+ * @since 5.5
+ */
+class KWIDGETSADDONS_EXPORT KSplitterCollapserButton : public QToolButton
+{
+    Q_OBJECT
+public:
+    /**
+     * @brief KSplitterCollapserButton create a splitter collapser
+     * @param childWidget the widget, child of the splitter, whose size is controlled by this collapser
+     * @param splitter the splitter which this collapser should be associated with.
+     */
+    explicit KSplitterCollapserButton(QWidget *childWidget, QSplitter *splitter);
+
+    /**
+     * Destructor
+     */
+    ~KSplitterCollapserButton() override;
+
+    /**
+     * @brief isWidgetCollapsed
+     * @return true if splitter is collapsed.
+     */
+    bool isWidgetCollapsed() const;
+
+    QSize sizeHint() const override;
+
+public Q_SLOTS:
+    /**
+     * @brief collapse, this function collapses the splitter if splitter is not collapsed.
+     */
+    void collapse();
+    /**
+     * @brief restore, call this function to restore previous splitter position.
+     */
+    void restore();
+    /**
+     * @brief setCollapsed, this function allows to collapse or not the splitter.
+     * @param collapsed if the splitter should be collapsed
+     */
+    void setCollapsed(bool collapsed);
+
+private Q_SLOTS:
+    KWIDGETSADDONS_NO_EXPORT void slotClicked();
+
+protected:
+    bool eventFilter(QObject *, QEvent *) override;
+    void paintEvent(QPaintEvent *) override;
+    void enterEvent(QEnterEvent *event) override;
+    void leaveEvent(QEvent *event) override;
+    void showEvent(QShowEvent *event) override;
+
+private:
+    std::unique_ptr<class KSplitterCollapserButtonPrivate> const d;
+};
+
+#endif /* KSPLITTERCOLLAPSERBUTTON_H */