Covers all 3 priority tiers from e2e_gaps.md: monitoring, headers, shutdown/drain, clustering, leaf nodes, gateways, MQTT, WebSocket, JetStream extensions, and advanced features.
Covers all 3 priority tiers from e2e_gaps.md: monitoring, headers, shutdown/drain, clustering, leaf nodes, gateways, MQTT, WebSocket, JetStream extensions, and advanced features.