dsh-firstrun: First-Run Health Check for DeepSeek Harness

dsh-firstrun is the first-run health check tool for DeepSeek Harness (DSH), designed to help new users overcome startup issues caused by environment configuration problems. Maintained by zoahdev under the MIT license, it verifies the toolchain (such as Node.js and pnpm), validates configuration settings (including Home directory, API Key, and workspace permissions), and provides recommended next steps. It supports both command-line and Agent use, runs in a read-only mode with zero runtime dependencies, and ensures that sensitive information is not leaked. Users can install it via `dsh plugin add dsh-firstrun` or run it directly with `npx dsh-firstrun`.