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/components/FeaturedBentoFromDb.tsx

@@ -66,7 +66,7 @@ export default async function FeaturedBento() {
       <div className="flex items-center gap-3 mb-4 md:mb-5 flex-wrap">
         <span className="section-label">Staff Editorial</span>
         <div className="flex-1 h-px bg-[#2a2a2a]" />
-        <Link href="/news?category=Featured" className="text-[11px] font-mono text-[var(--color-text-info,#60a5fa)] hover:underline whitespace-nowrap">
+        <Link href="/news/featured" className="text-[11px] font-mono text-[var(--color-text-info,#60a5fa)] hover:underline whitespace-nowrap">
           All featured →
         </Link>
       </div>