Fix homescreen includes, accessibility, and popup clamp

Remove duplicate KService include in favouritesmodel.cpp. Add
keyboard navigation and accessibility role to CategoryPanel
tiles. Clamp the FavouritesBar thumbnail popup position to
screen bounds so it does not overflow offscreen on edge items.

containments/homescreens/folio/favouritesmodel.cpp

@@ -4,7 +4,6 @@
 #include "favouritesmodel.h"
 #include "homescreenstate.h"
 
-#include <KService>
 #include <QByteArray>
 #include <QDebug>
 #include <QJsonArray>

containments/homescreens/folio/qml/CategoryPanel.qml

@@ -179,7 +179,26 @@ Rectangle {
                         anchors.fill: parent
                         hoverEnabled: true
                         cursorShape: Qt.PointingHandCursor
+                        activeFocusOnTab: true
                         onClicked: root.categorySelected(tile.catId)
+
+                        Keys.onPressed: (event) => {
+                            if (event.key === Qt.Key_Return || event.key === Qt.Key_Enter || event.key === Qt.Key_Space) {
+                                root.categorySelected(tile.catId);
+                                event.accepted = true;
+                            }
+                        }
+
+                        Accessible.role: Accessible.Button
+                        Accessible.name: tile.catName
+
+                        Rectangle {
+                            anchors.fill: parent
+                            color: "transparent"
+                            border.color: Kirigami.Theme.highlightColor
+                            border.width: tileArea.activeFocus ? 2 : 0
+                            radius: parent.parent.radius
+                        }
                     }
                 }
             }

containments/homescreens/folio/qml/FavouritesBar.qml

@@ -642,12 +642,12 @@ MouseArea {
         x: {
             if (!targetDelegate) return 0
             var delegateGlobal = targetDelegate.mapToGlobal(0, 0)
-            return Math.max(0, delegateGlobal.x + (targetDelegate.width - width) / 2)
+            return Math.max(0, Math.min(Screen.width - width, delegateGlobal.x + (targetDelegate.width - width) / 2))
         }
         y: {
             if (!targetDelegate) return 0
             var delegateGlobal = targetDelegate.mapToGlobal(0, 0)
-            return delegateGlobal.y - height - Kirigami.Units.smallSpacing
+            return Math.max(0, Math.min(Screen.height - height, delegateGlobal.y - height - Kirigami.Units.smallSpacing))
         }
 
         onVisibleChanged: {