The GitHub App check was gated behind #[cfg(feature = "server")] so it
never ran in CLI-only builds. It also only checked whether env vars were
set, not whether the key could actually sign JWTs.
- Move GithubAppStatus and check_github_app out of the server feature gate
- Try sign_app_jwt to validate the private key, catching corrupt keys
- Show app_id and slug in doctor output
- Keep server-only fields (client_id, client_secret, webhook_secret)
behind #[cfg(feature = "server")]
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>