dsh-session-settings: DeepSeek Harness Session Settings and MCP Tool Management Plugin

`dsh-session-settings` is a web interface plugin for DeepSeek Harness (DSH) that allows users to manage session-specific settings in real time via the web without restarting the service. Core features include managing MCP servers and skills in the sidebar, dedicated session tabs (supporting global defaults, parent session inheritance, or custom modes), and independent toggles for MCP tools and skills. Licensed under the MIT License, this plugin requires DSH version `>= 0.1.5-rc.1` and Node.js `^22.19 || >=24`, and provides fine-grained control over model routing, protocols, and skill scheduling.