homepage: All featured → goes to dedicated /news/featured page

Was linking to /news?category=Featured which silently fell back to the
unfiltered /news listing because "Featured" isn't in CATEGORIES and the
filter is tag-based, not category-column-based.

Adds getLegacyFeaturedArticles() that mirrors FeaturedBento's query
(category ILIKE 'featured', featured-flag-first sort) at limit 200, and
a thin /news/featured route that reuses NewsPageClient.

src/lib/articles/legacy-source.ts

@@ -317,6 +317,23 @@ export async function getLegacyArticlesBySection(
   return merged.slice(0, limit).map((m) => m.article);
 }
 
+export async function getLegacyFeaturedArticles(limit = 200): Promise<Article[]> {
+  try {
+    const { data, error } = await client()
+      .from("wp_imported_posts")
+      .select(SELECT_COLS + ",featured")
+      .eq("status", "published")
+      .ilike("category", "featured")
+      .order("featured", { ascending: false })
+      .order("wp_published_at", { ascending: false, nullsFirst: false })
+      .limit(limit);
+    if (error || !data) return [];
+    return (data as ImportedPostRow[]).map((r) => rowToArticle(r));
+  } catch {
+    return [];
+  }
+}
+
 // Default raised from 50 → 5000 because users expect search to return
 // every match. The 29k-article archive is small enough that title/excerpt
 // ilike filters stay fast even without an explicit cap. Pass a smaller