Currently, we have some freaky behaviours in that value is repurposed through the lifetime of a prompt.

Let's take autocomplete multi for example. It goes like this:

• value is empty
• user types in foo
• value is now "foo"
• user selects the "foo" option with <TAB>
• user presses <RETURN>
• value is now [ 'foo' ]

so the type is basically string | undefined | string[]

this is pretty confusing and means functions which deal with value (like validate) have no clue what type the value will be

could be a string, an array, an object, whatever. its basically unknown

i think we should mutate some internal value which represents user input (when they type something in), and mutate value for the prompt's strongly typed value