wjt0321/dsh-git-proxy: On-Demand GitHub Proxy Plugin for DeepSeek Harness

The DeepSeek Harness plugin `dsh-git-proxy` provides a Web UI toggle for configuring Git and SSH proxies on demand to access GitHub. It supports one-click proxy enable/disable, saving proxy addresses, testing connectivity, and automatically restoring direct connections after downloads are complete. The plugin relies on the `connect` tool from Git for Windows, does not support authenticated proxies or IPv6, and only affects GitHub-related operations.