docs: public List<String> commands(boolean sys, boolean app) {
          C.List<String> list = C.newList();
          Act.Mode mode = Act.mode();
          boolean all = !sys && !app;
          for (String s : registry.keySet()) {
              boolean isSysCmd = s.startsWith("act.");
              if (isSysCmd && !sys && !all) {
                  continue;
              }
              if (!isSysCmd && !app && !all) {
                  continue;
              }
              CliHandler h = registry.get(s);
              if (h.appliedIn(mode)) {
                  list.add(s);
              }
          }
          return list.sorted(new $.Comparator<String>() {
              @Override
              public int compare(String o1, String o2) {
                  boolean b1 = (o1.startsWith("act."));
                  boolean b2 = (o2.startsWith("act."));
                  if (b1 & !b2) {
                      return -1;
                  }
                  if (!b1 & b2) {
                      return 1;
                  }
                  return o1.compareTo(o2);
              }
          });
      }