dsh-http-debug: DeepSeek Harness HTTP Network Debugging Toolkit

`dsh-http-debug` is a zero-dependency HTTP client plugin designed for the DeepSeek Harness (DSH) ecosystem. It focuses on raw HTTP protocol debugging, providing general-purpose request construction, SSRF and private network protection, request history logging, HAR export, and WAF-friendly features. The tool includes three commands: `http_request`, `http_history`, and `http_rules`, supporting request execution, replay, and SSRF whitelist management. With hard size limits and built-in safety checks, it effectively prevents context overflow and security risks, making it a practical utility for fine-grained network debugging.