websearch-plugins: No-API-Key Aggregated Search and Scraping Plugin for DeepSeek Harness

The websearch-plugins plugin for DeepSeek Harness (DSH) is packaged as a standard plugin featuring 16 built-in domestic and international search engines and SSRF-protected fetching, and supports the `web_search` and `web_fetch` tools. It offers aggregated search and result filtering, browser emulation via dependency-free Node.js fetch, and automatic parsing of JavaScript-rendered pages. It can be invoked directly after installation, but note that SSRF protection blocks private network addresses.