Add watcher for .show file in config directory

Draw attention when the .show file is created.
It is created when attempting to open another
instance of Mirage with the same configuration.

src/gui/Window.qml

@@ -3,6 +3,7 @@
 import QtQuick 2.12
 import QtQuick.Controls 2.12
 import Qt.labs.platform 1.1
+import Qt.labs.folderlistmodel 2.12
 import "Base"
 import "PythonBridge"
 
@@ -23,7 +24,7 @@ ApplicationWindow {
     property var uiState: ({})
     property var history: ({})
     property var theme: null
-    property bool closing: false
+    property string configDir
 
     readonly property var visibleMenus: ({})
     readonly property var visiblePopups: ({})
@@ -142,4 +143,21 @@ ApplicationWindow {
             }
         }
     }
+
+    FolderListModel {
+        id: showUpWatcher
+        folder: window.configDir
+        showDirs: false
+        showHidden: true
+        nameFilters: [".show"]
+
+        onCountChanged: {
+            if (count) {
+                window.drawAttention()
+                py.importModule("os", () => {
+                    py.call("os.remove", [get(0, "filePath")])
+                })
+            }
+        }
+    }
 }