fix(article): remove duplicate excerpt rendering above the article body

Excerpt was rendered both as a standalone <p> at the top of the article
header AND as the first paragraph of the body content (because PR
submissions paste the lede into both fields). Drop the header copy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/articles/[slug]/ArticleDetailClient.tsx

@@ -258,8 +258,6 @@ export default function ArticleDetailClient({ article, relatedArticles, relatedF
               <div className="mb-4">
                 <StarRating seed={article.slug} publishedAt={article.publishedAt || article.date} size="md" />
               </div>
-              <p className="font-body text-lg text-[#999] mb-6 leading-relaxed">{article.excerpt}</p>
-
               {/* Article Meta */}
               <div className="flex items-center justify-between py-4 border-t border-b border-[#222]">
                 <div className="flex items-center gap-3">