ULID generation, parsing, and utilities.

Implements the ULID spec:
- 26-char Crockford Base32 encoded string
- 48-bit timestamp (millisecond Unix epoch) + 80-bit random component
- Lexicographically sortable
- Monotonic generation within same millisecond

UUID v4 generation, parsing, and validation.

Implements RFC 4122 UUID v4 (random):
- 36-char hex-hyphenated string (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
- 122 bits of randomness, version 4 (0100), variant 1 (10xx)
- Pure Clojure, zero dependencies beyond java.security.SecureRandom

UUID v7 generation, parsing, and validation.

Implements RFC 9562 UUID v7 (time-ordered):
- 36-char hex-hyphenated string (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
- 48 bits of big-endian Unix timestamp in milliseconds (bytes 0-5)
- 12 bits of randomness (rand_a, bytes 6-7) with version 7 (0111) in byte 6
- 62 bits of randomness (rand_b, bytes 8-15) with variant 10 in byte 8
- Lexicographically sortable by creation time
- Pure Clojure, zero dependencies beyond java.security.SecureRandom