// Package health provides a stdlib http.Handler for service health checks.
//
// Register checkable components and mount the handler at a health endpoint:
//
//	handler := health.NewHandler(logger, db, cache, queue)
//	r.Get("/health", handler)
//
// The handler runs all checks concurrently with a 5-second timeout.
// It returns HTTP 200 (UP or DEGRADED) or HTTP 503 (DOWN).
package health