v1.2.1

Fixed

• An empty answer no longer ends a run silently (SPEC §10.1 rule 8). The v1.2.0 fallback
  covered only the max_steps / max_tool_calls final step: a model that went text-only
  after §6.7 disabled tools (a repeat, or two empty results) and then replied with nothing
  ended the run completed / end_turn with an empty answer. Now an empty step (no text, no
  tool calls) is dropped and re-asked once without tools, with an ephemeral engine note;
  if that is empty too, the run ends completed with a localized fallback and
  answer_source: "fallback". New journal event empty_answer, new step_start field
  empty_answer_reask. limits.final_answer: false keeps the old behavior.