// NOTE: We only unpack `either` errors that occurred *at the same level* as this error, ie. where there's directly a case of `either(either(...), ...)`, without any kind of data nesting (like `arrayOf` or `hasShape`) inbetween. Nested-data failures should still be shown separately, as their resolution strategy is actually different; unlike same-level nested `either` errors, where the nesting is purely an implementation detail that allows composing sets of alternatives together.