runBackCli function
CLI adapter for fdb back. Accepts no flags; emits one of:
POPPED (success)
ERROR: fdb_helper not detected in running app. ... (no helper)
ERROR: Navigator could not pop — already at root (at root)
ERROR: <message> (VM error / generic)
(AppDiedException rethrown for dispatcher's _formatAppDied) (app died)
Implementation
Future<int> runBackCli(List<String> args) => runCliAdapter(ArgParser(), args, _execute);