Windows support

Filetree.py

@@ -9,7 +9,7 @@ from typing import Callable, Optional
 
 import flet as ft
 
-from Core import AppConfig, DragGroup, MoveIntoDirectory, NotificationStyle, Palette
+from Core import AppConfig, DefaultFiletreeRoot, DragGroup, MoveIntoDirectory, NotificationStyle, Palette
 
 
 class _FiletreeNode:
@@ -119,7 +119,7 @@ class Filetree(ft.Container):
     ):
         self.OnNavigate = OnNavigate
         self.Config = Config
-        self.RootPath = RootPath or Path("/")
+        self.RootPath = RootPath or Path(DefaultFiletreeRoot)
         self.OnFilesMoved = OnFilesMoved
         self.SelectedNode: Optional[_FiletreeNode] = None