:sig
String sha256_hex(String data)

:params
data : bytes to hash
return value : the SHA-256 digest as a 64-character lowercase hex string

:content
Returns the SHA-256 digest of `data` as hex text. Use it for checksums, cache keys, and content fingerprints where you want a printable digest. For the raw 32-byte digest use `sha256()`.

:example
print(sha256_hex("abc"), "\n");

:see
>sys
sha256
hmac_sha256_hex
gen_sha1
