// ByteCursorBox (MVP): byte-based helpers (placeholder on top of String)
// Note: MVP assumes input as String; true byte buffer support to be added.
static box ByteCursorBox {
  len_bytes(s) { return s.length() }  // MVP: not true bytes yet
  slice_bytes(s, i, j) { return s.substring(i, j) }
  find_bytes(s, pat, from) {
    if from { return s.indexOf(pat, from) }
    return s.indexOf(pat)
  }
  to_string_utf8(s, strict) { return s } // MVP: identity
}