runStatusCli function
CLI adapter for fdb status. Accepts no flags; emits:
RUNNING=true|false (always)
PID=<pid> (only if PID file present and process alive)
VM_SERVICE_URI=<uri> (only if running and VM URI is known)
Implementation
Future<int> runStatusCli(List<String> args) => runCliAdapter(ArgParser(), args, _execute);