This site describes solve-engine as it is on main: 2.43.0, which npm does not have yet. npm installs 2.40.0, so a page may show an answer that version does not give yet.
RANDOM_PACKAGE
const RANDOM_PACKAGE: IEnginePackage;Defined in: packages/engine/src/packages/random/RandomPackage.ts:15
Everyday randomness and identifiers (issue #241): uuid, coin,
random hex N, pick(a, b, c) and shuffle [a, b, c].
A companion to the dice package, which owns dice-notation rolls; this is the
general pickers. On by default and removable. Randomness comes from the same
source the engine’s random() and roll already use, so nothing here is any
more or less reproducible than the rest of the engine, which is why the docs
page for it carries no proven example values.