xrxs-dsh-harmony-publish: Safely hand over the HarmonyOS release pipeline to DSH Agent

This DSH plugin exposes the HarmonyOS release pipeline of the `harmony-agc-publish` Codex skill to the Agent, wrapping it with credential database parsing, precise substring masking, and manual approval. It supports three release modes: `buildOnly`, `upload`, and `submit`. Configuration uses whole-object overrides based on profiles, and keys can only be processed via `credentialRefs`. It includes DSH Web client cards, audit logs, and fixed exit codes. Installation methods, configuration items, typical call sequences, and the security model are all compiled from the GitHub README.