notifitem: handle notification closed by app to prevent dismiss-on-destroyed error

modules/NotifItem.qml

@@ -42,6 +42,14 @@ QtObject {
         return d > 0 ? d + "d" : h + "h";
     }
 
+    // App closed the notification from its side — remove from our list while the object is still alive
+    readonly property Connections _notifConn: Connections {
+        target: root.notification
+        function onClosed() {
+            M.NotifService.dismiss(root.id);
+        }
+    }
+
     function beginDismiss() {
         if (state === "visible")
             state = "dismissing";