Replace Fabric.js Canvas dependency with SceneManager. UndoManager now serializes via sceneManager.serialize() and restores via loadScene() with diff-based reconciliation (no flicker, no CORS workarounds).
Replace Fabric.js Canvas dependency with SceneManager. UndoManager now serializes via sceneManager.serialize() and restores via loadScene() with diff-based reconciliation (no flicker, no CORS workarounds).