open method
Opens the assistant: starts a session (if none / if the prior one ended or failed) and expands the panel.
Implementation
Future<void> open() async {
final terminal =
_status == SessionStatus.ended || _status == SessionStatus.failed;
if (_session != null && terminal) {
await _disposeSession();
}
if (_session == null) _startSession();
_setPanelOpen(true);
}