start method
Binds the TLS endpoint and starts the liveness watchdog.
Implementation
Future<void> start() async {
if (_endpoint != null) return;
await _resolveUid();
broker.start();
_endpoint = await WsServerEndpoint.bind(
host: config.host,
port: config.port,
securityContext: config.securityContext,
onConnection: broker.accept,
);
}