Encode/decode Base58 locally (Bitcoin alphabet). Includes Base58Check (double-SHA256 checksum) builder/verifier.
Input can be UTF-8 text or hex bytes. Output is Base58.
Base58 alphabet (Bitcoin): 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz
This is the classic Bitcoin-style check encoding: Base58(version || payload || SHA256(SHA256(version||payload))[0..4]).