fix(editor): guard against erroneous undo/redo

Before this change, if either undoing or redoing threw an error, the editor
would be stuck in the "preserve keys" state, causing duplicate keys to appear
everywhere, cascading into all sorts of problems and disruptive typing.

packages/editor/src/editor/plugins/createWithUndoRedo.ts

@@ -12,7 +12,7 @@ import {type Descendant, Editor, Operation, Path, type SelectionOperation, Trans
 import {type PatchObservable, type PortableTextSlateEditor} from '../../types/editor'
 import {debugWithName} from '../../utils/debug'
 import {fromSlateValue} from '../../utils/values'
-import {withPreserveKeys} from '../../utils/withPreserveKeys'
+import {PRESERVE_KEYS, withPreserveKeys} from '../../utils/withPreserveKeys'
 
 const debug = debugWithName('plugin:withUndoRedo')
 const debugVerbose = debug.enabled && false
@@ -166,6 +166,7 @@ export function createWithUndoRedo(
             Transforms.deselect(editor)
             editor.history = {undos: [], redos: []}
             SAVING.set(editor, true)
+            PRESERVE_KEYS.set(editor, false)
             editor.onChange()
             return
           }
@@ -212,6 +213,7 @@ export function createWithUndoRedo(
             Transforms.deselect(editor)
             editor.history = {undos: [], redos: []}
             SAVING.set(editor, true)
+            PRESERVE_KEYS.set(editor, false)
             editor.onChange()
             return
           }