v2.22.4

A patch release: nothing the model reads changes.

• The start-up prime warms the prompt the first turn actually sends. It ran
  before any turn had set the session config, so it built the default
  prompt (date and working directory in its second line), which shared 88
  characters with the first turn's stable prompt. The prime was discarded
  and the first turn rebuilt the dialog. Measured on a server that had
  already served a session, with the question typed 5 s after the prime
  (the owner's median over 85 REPL sessions): first model call 13.7–14.7 s
  with one Rewind failure every time, now 6.0–6.3 s with none (4 paired
  runs). On a freshly started server the first Rewind fails once whatever
  is cached (a runtime quirk, measured the same night), so the first turn
  after a server start still pays one rebuild.