Optional randomness source for GUID generation: a Math.random-style
function returning floats in [0, 1). Pass a seeded generator to make GUID
generation reproducible (e.g. for byte-deterministic file output); omit it
to use Web Crypto when the runtime provides it, falling back to
Math.random when it does not. A seeded source trades global uniqueness
for reproducibility - only use one where that is the point.
Optional randomness source for GUID generation: a
Math.random-style function returning floats in[0, 1). Pass a seeded generator to make GUID generation reproducible (e.g. for byte-deterministic file output); omit it to use Web Crypto when the runtime provides it, falling back toMath.randomwhen it does not. A seeded source trades global uniqueness for reproducibility - only use one where that is the point.