The holiday-week stage ranked every placement as a donor once per
public-holiday week, although the ranking depends only on the plan. The
weeks of one plan now share each placement's released objectives; each
week still skips its own dates and walks the placements in the same
order with the same yields.
Part of #302.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
