:sig
String base64_encode(String raw)

:params
raw : binary-safe source bytes
return value : the Base64-encoded text

:content
Encodes bytes as Base64 text. UCE strings are binary-safe, so `raw` may contain NUL and other non-text bytes — handy for embedding `random_bytes()` or a `sha256()` digest in headers, cookies, or JSON.

:example
print(base64_encode("hello"), "\n");

:see
>uri
base64_decode
random_bytes
