Request: Automatic timeout

Would it be possible to have something like an `automatic_timeout` parameter after which the prompt automatically returns the `default` value?
This would be useful to show a prompt but proceed automatically if there were no user interaction.

Start by reviewing the prompt/input API and how the `default` value is currently handled. Define the expected `automatic_timeout` behavior, including what happens when there is no user interaction, and verify that the prompt returns the default value after the timeout.

Written by the indexing model from the issue text.