dsh-side-chat: Read-only Side Chat Plugin for DeepSeek Harness

dsh-side-chat is a read-only plugin for DeepSeek Harness (DSH) designed to address the issue where temporary queries interfere with the main workflow during long-running tasks. It achieves this by creating a side session alongside the main session that inherits the completed context, allowing the main Agent to continue running independently without interference while users perform side queries. At its core, the plugin enforces mandatory read-only constraints with a sandbox approval policy set to "never". It exposes only read-only tools available within the parent context and rejects non-read-only operations as well as nested code patterns. The interface supports the Better Sidebar or adaptive floating windows. It retains drafts and logs when hidden or minimized, entering a parked state only after confirmation of termination or 30 minutes of inactivity from both parties. It is designed for the DSH Web environment (Node.js ^22.19.0+) and is installable via npm.