relay_first::read_u64 and ListReposProducer::next_completion read the relay-first pass counters as big endian u64s, and cursor_display decodes the msgpack crawler cursor, all through codec functions passed as values that the representation audit couldn't see. the new tests store a known marker or cursor and check what each reader gets back, including the error or fallback for a malformed value. flipping the reads to from_le_bytes, or the cursor decode to json, fails them.