StreamManager.Capture now accounts for full message size (subject +
payload + 16-byte overhead) when checking MaxBytes, matching Go's
memStoreMsgSize. PullConsumerEngine uses stream FirstSeq instead of
hardcoded 1 for DeliverAll after purge. Fix 6 tests with Go parity
assertions and updated MaxBytes values.
Reconcile close reason tracking: feature branch's MarkClosed() and
ShouldSkipFlush/FlushAndCloseAsync now use main's ClientClosedReason
enum. ClosedState enum retained for forward compatibility.
Replace empty catch blocks with meaningful log statements in NatsServer,
NatsClient, and Program. Add WaitForReadyAsync() to NatsServer for
deterministic server startup. Replace Task.Delay/Thread.Sleep in tests
with PING/PONG protocol flush and SubscribeCoreAsync for reliable
subscription synchronization.