nx_consul_registry.nx

nx_consul_registry.nx -- sovereign SERVICE REGISTRY + HEALTH-GATED DISCOVERY (HashiCorp Consul-class; the first rung of the sovereign-Consul arc). Register service instances (name, addr, port, health); discover(name) returns ONLY routable instances (health != CRITICAL) that are still registered -- so traffic NEVER routes to a down or deregistered instance. The health gate is the core safety property Consul exists to provide. Composes toward nx_dns_authoritative (service DNS), nx_reach_probe (the live health source), nx_vault (service-mesh mTLS, later). Pure logic over the registry arrays. license_tier: ORIGINAL