Homepage: show only the latest news announcement

[devin-ai-integration]

Summary

The homepage announcement stack rendered three cards (two newest news posts + newest blog post), so stale posts sat above the current one. Now it renders only the newest news post:

- news_section.pages | slice(end=2)
+ news_section.pages | slice(end=1)
- {# blog card block #}

Once the BMT 2026 / BMT 2026 Online registration post is published it will be the sole card.

Link to Devin session: https://app.devin.ai/sessions/b2cad97fe85e4ad7aa2ed105e43fc39b
Requested by: @alphdelta

---

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[devin-ai-integration]

Tested locally (Zola dev server on the PR branch) — all checks passed.

Homepage announcement stack now renders a single "News" card; the "Blog" card and second news card are gone.

• Exactly one announcement card, label "News", title "BMT 2026 will be held on November 14, 2026"
• No blog card / no second news card anywhere on the homepage
• Card links to /news/bmt-2026-date-set/, post page renders correctly
• Banner, event cards, newsletter form, sponsors, footer unchanged — no layout or template errors

Regression: listings unaffected

/news/ still lists all posts (2026 → 2023):

/resources/blog/ still lists all 5 blog posts:

Note on permalink

The newest news post's URL is /news/bmt-2026-date-set/ — Zola strips the 2026-05-27_ filename date prefix. Pre-existing behavior, unrelated to this PR.