dsh-tool-encoding: DSH UTF-8 Text Encoding, Hash, and UUID Tool Plugin

dsh-tool-encoding is an encoding and hashing tool plugin for DSH agent workflows, providing base64/base64url/url/hex encoding and decoding for UTF-8 text, hashing (md5/sha1/sha256/sha512), and UUID v4 generation. It is designed as a zero-dependency, zero-process, pure function, aiming to replace shell external commands and reduce process scheduling and concatenation costs. All operations are processed as UTF-8 text, with an input limit of 1 MB and an output limit of 4 MB. The tool features strict validation mechanisms, including RFC 4648 canonical validation, fatal mode UTF-8 decoding, rejection of isolated surrogates, and hex decoding validity checks. This plugin is suitable for web and high-performance applications.