- myconf_t gains peers_cfg (xce_cluster_config_t) populated from --peers
- controller/main.c: parse --peers host:port,... via argp; ca_cert_path
auto-derived from workdir/certs/xce.crt (no --ca-cert flag needed)
- cluster_init: derive my_priority from position in peers list (index 0 =
primary); fall back to 0 when --peers not given (single-node mode)
