dsh-plus-plus: Local Control Plane for DeepSeek Harness

DSH++ is a local-first DSH control plane plugin designed to address challenges developers face in understanding plugin permissions and the lack of operational tooling. It provides three core capabilities: plugin security auditing and risk classification via `audit`; workflow regression testing via `test` with CI integration support; and lifecycle management via `doctor` and snapshot functionality. The plugin requires no third-party dependencies and, after installation, can be managed through a CLI or a local web console (http://127.0.0.1:4848) to control configurations, credentials, and backups. Note that credentials are stored in a local `.env` file, and the plugin runs with the same privileges as the DSH process.