- Fix assign_tag sending Content-Type header with no body - Mark collectives_update_collective as idempotent (no ETag involved) - Raise OCSError when 'data' key missing instead of silent fallback - Tighten color validator to 3 or 6 hex chars only - Add comment explaining null emoji semantics in set_page_emoji Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>