DeepSeek Harness Plugin: dsh-harness-updater

`dsh-harness-updater` is a plugin for DeepSeek Harness (DSH) designed to automate the update process for Claude Code and Codex CLI. It automatically detects the difference between the local version and the latest version, identifies the installation channel (such as npm or Homebrew), and provides interactive update cards. By using a mandatory user trigger, a request lock, and secure timeout mechanisms, it ensures the update process is safe and reliable. After installation, users can click the update button in the settings, after which the plugin automatically runs the corresponding upgrade command and verifies the result, significantly improving developer efficiency in maintaining their toolchain.