deepseek-harness-gui: Running the dsh Web GUI in a Native Glimpse Window

The `deepseek-harness-gui` plugin of DeepSeek Harness (DSH) embeds the DSH Web GUI into a native Glimpse window, eliminating the fragmented experience of manually switching between the application and a browser. This plugin functions solely as a navigator and can be started using parameters such as `--gui`. During installation, `--allow-build=glimpseui` must be explicitly declared. It supports Windows, macOS, and Linux, providing a more seamless local interactive experience.