//! Interactive prompt helpers for the CLI.
//!
//! The `prompt`/`prompt_optional`/`prompt_secret` family reads from stdin /
//! the TTY; the `prompt_keep`/`prompt_keep_opt`/`prompt_yesno` variants are
//! used by the edit handlers to keep current values when the user hits enter
//! at a blank prompt. `prompt_secret` honours `RELICARIO_TEST_ITEM_SECRET`
//! so integration tests (which don't have a TTY) can inject secrets.