GitHub Copilot sign-in for DeepSeek Harness

Key features

• Device-flow sign-in — no token to create or paste.
• Model selector shows no GitHub Copilot group after restart The plugin loaded in a previous process that didn't pick up the new package.
• the credential is stored automatically.
• Automatic refresh, handled downstream — the credential carries your long-lived GitHub token.
• The harness route exchanges it for a short-lived Copilot token, refreshes it, and derives your account's API endpoint (individual, business, or enterprise) on its own.