v2.1.1

Changed

• The server instructions put wording the Lens inside the session flow: checkpoint, end_session, then get_lens and
  write_lens_words. Asked for a normal two-file task without a word about the Lens, Claude Code wrote the Lens's words
  in 5 of 5 runs, against 3 of 5 when it was a separate line (npm run eval:lens).