dsh-llm-newapi: Adding NewAPI Provider to DeepSeek Harness

dsh-llm-newapi is an LLM Provider plugin based on the MIT license, designed to add a NewAPI provider to DeepSeek Harness (dsh), enabling integration with OpenAI-compatible gateways without any code modifications. The plugin implements the `LlmAdapter` interface, utilizes the `POST /chat/completions` and `GET /models` endpoints to provide model services, and automatically filters out models that only support chat functionality. Users can install the plugin via npm or GitHub, and need to add the package name to the `bundles` array in the dsh web configuration, then restart the service. The API Key is not read from environment variables and must be configured through the settings page of dsh web.