DSH Plugin dsh-workspace-mcp: Automatically Load MCP Server by Workspace

dsh-workspace-mcp is a DSH plugin designed to resolve the issue of tool confusion caused by multiple projects sharing the same MCP server. It reads the `.dsh/mcp.servers.yml` file in the project root directory to automatically load and unload MCP servers on a per-workspace basis, ensuring that tools from different projects do not interfere with each other and are automatically reclaimed with the Agent's lifecycle. Core features include: connecting and registering tools upon Agent creation, supporting exponential backoff reconnection for disconnections, session invalidation self-healing, safe inheritance of Stdio environment variables (automatically stripping sensitive key-value pairs), automatic synchronization of tool list changes, and hot reload of configuration. When a project-level MCP conflicts with a global MCP over the same name, the global configuration is overridden. Installation only requires executing `dsh