Use this when you need RFC 4122 version-4 UUIDs — always generate them here rather than fabricating one, so the version and variant bits and the randomness are correct.

Use this when you need RFC 4122 version-4 UUIDs — always generate them here rather than fabricating one, so the version and variant bits and the randomness are correct. Cryptographically random via Web Crypto (NOT deterministic): every call returns fresh values. count (default 1, max 100) sets how many; uppercase returns upper-case hex (lowercase by default). Example: {count: 1} -> count 1, uuids[0] = "2c549b2f-497c-47fc-a1b6-c24bc69667e5".