`Result.Err` recovering

Currently there's only

Result.withDefault :
    a -> Result x a -> a

which the issue suggests to replace with

• Result.valueElseOnError/recover :
      (x -> a) -> Result x a -> a
  

  which is lazy by default and makes it nearly impossible to forget error values.

• additionally, an andThen but for the error case would be a common helpful operation

  Result.onErrorTry/recoverTry :
      (x -> Result a y) -> Result x a -> Result y a
  

Start by locating the existing Result.withDefault implementation and the surrounding Result API in the core package. Review how error-handling helpers are named and tested, then determine whether the proposed recovery and error-retry operations fit the package's conventions; done means the agreed API is implemented with coverage for its lazy recovery and error-case behavior.