All external services (database, Discord/GitHub OAuth, S3) can now be individually disabled by omitting their environment variables. The server gracefully degrades functionality when services are unavailable. Partial configuration of any service group triggers a clear error at startup.
- Database: Falls back to dummy pool when DATABASE_URL is unset
- OAuth: Providers only registered when credentials are complete
- S3: Image storage disabled when credentials are missing
- Health checks reflect actual configuration state
