Replace Task.Delay polling with PeriodicTimer in NatsServerProcess readiness checks and extend StartAsync to also TCP-poll the monitor port when enabled, so MonitorServerFixture is guaranteed ready before tests run.
- Fix pull consumer fetch: send original stream subject in HMSG (not inbox) so NATS client distinguishes data messages from control messages - Fix MaxAge expiry: add background timer in StreamManager for periodic pruning - Fix JetStream wire format: Go-compatible anonymous objects with string enums, proper offset-based pagination for stream/consumer list APIs - Add 42 E2E black-box tests (core messaging, auth, TLS, accounts, JetStream) - Add ~1000 parity tests across all subsystems (gaps closure) - Update gap inventory docs to reflect implementation status
