google news phase 1

- Homepage / Industry News query filters wp_imported_posts to
  ai_rewritten_at IS NOT NULL so raw press releases never surface on
  the editorial feed (NewsArticle JSON-LD was already in place).
- New /news-sitemap.xml route emits a Google News sitemap covering
  rewritten editorial published in the last 48 hours, with
  news:publication + news:publication_date + news:title + keywords.
- robots.ts now points crawlers at both sitemap.xml and
  news-sitemap.xml.

After deploy, submit broadcastbeat.com to Google News Publisher Center
to start serving in News.

src/lib/articles/legacy-source.ts

@@ -281,6 +281,9 @@ export async function getLegacyArticlesBySection(
       .from("wp_imported_posts")
       .select(SELECT_COLS)
       .eq("status", "published")
+      // Google News-safe surface: only show articles that have been AI-rewritten
+      // into original editorial. Raw press-release imports are excluded.
+      .not("ai_rewritten_at", "is", null)
       .order("wp_published_at", { ascending: false })
       .limit(limit);
     const tags = SECTION_TAGS[section];