feat: save stroke as soon as it is created at the beginning of touch

Memola/Canvas/View/Bridge/ViewController/CanvasViewController.swift

@@ -62,9 +62,6 @@ class CanvasViewController: UIViewController {
     override func viewDidDisappear(_ animated: Bool) {
         super.viewDidDisappear(animated)
         history.resetRedo()
-        withPersistence(\.backgroundContext) { context in
-            context.refreshAllObjects()
-        }
     }
 }