Healthcheck Prometheus compatibility

The package consumes current core HealthReport values and publishes ESM, CommonJS, and declarations. It has no Prometheus SDK dependency.

Repository tests cover serializer behavior. This documentation does not claim compatibility with every Prometheus server release. Validate scrape content and content type in your deployed monitoring stack.

The serializer has no Node engine or Prometheus peer range. Its current repository verification target is Node 22 and the HealthReport from Core 4.1.0. Prometheus server versions remain application-verified because the package only emits text.