bing-web-search: DeepSeek Harness Web Search Plugin

bing-web-search is a zero-configuration web search plugin for DeepSeek Harness. It automatically falls back to free Bing search when no API key is provided, and uses Tavily for higher-quality results when an API key is available. To install it, place the directory in `node_modules`, register the plugin in `cordis.patch.yml`, and specify the search provider. The API key can be configured via environment variables or a credentials file, and the plugin also supports setting a timeout and result count. Developers can use it as-is without any configuration, or use Tavily to get more accurate search results and summaries.