showEditor method
Shows the native contact editor for contactId. Returns the saved
contact's ID, or null if the user cancelled or deleted the contact.
Deletion is offered by the system editor itself (on iOS, from iOS 26 onwards), and is not distinguishable from cancelling: both return null. Re-reading the contact by ID tells the two apart.
Same permissions as showViewer.
Implementation
Future<String?> showEditor(String contactId) =>
_invoke<String>('native.showEditor', {'contactId': contactId});