The state-migration chown invoked ${pkgs.coreutils}/bin/sh, which does not
exist (coreutils ships chown, not sh), so ExecStartPre exited 203/EXEC on
every boot. hive-c0re hit its start limit and never came up, so the gateway
returned 502 Bad Gateway. Call chown directly with the +- prefix (run as
root, tolerate failure) instead of going through a shell for '|| true'.