dsh-firstrun v0.1.0

First-run health check for DeepSeek Harness.

• 8 checks: node/pnpm/dsh toolchain, home, profile, API key (names only), workspace, registry
• Actionable next steps; values never printed
• CLI + agent-callable quickstart tool, dsh-firstrun/v1 reports
• Windows shim-safe exec; 7 unit tests, packed integration, dsh web boot smoke