feat: port sessions 12 & 13 — Events/Monitoring/MsgTrace + Config Reload
Session 12 (218 features, IDs 854-950, 2166-2251, 2405-2439):
- EventTypes: system subjects, event message types, InternalState, ConnectEventMsg,
DisconnectEventMsg, AccountNumConns, ServerIdentity, DataStats
- MonitorTypes: Connz, ConnInfo, ConnzOptions, ConnState, ProxyInfo, TlsPeerCert
- MonitorSortOptions: SortOpt, ConnInfos, all 13 sort comparers
- MsgTraceTypes: IMsgTrace, MsgTraceBase + 6 concrete types, custom JSON converter
Session 13 (89 features, IDs 2800-2888):
- ReloadOptions: IReloadOption interface, NoopReloadOption base, 50 option classes
covering logging, TLS, auth, cluster, JetStream, MQTT, OCSP, misc
ce45dff994