dsh-armor-switch: Reversible Delivery Contract Plugin

`dsh-armor-switch` is a reversible delivery contract plugin for DeepSeek Harness. It registers rules through system prompts and runtime context, provides host and Profile cleaning capabilities, and uses `original-fs` to process Electron files, achieving fine-grained control over model behavior. The plugin has zero external dependencies, supports hot switching and graphical management, but it does not take effect under the Minimal preset, and host cleaning changes require a process restart before they can be read by the model.