Homepage: show two current series side by side as compact cards; v2.9.4

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/App.tsx

@@ -1341,7 +1341,7 @@ function LandingPage({ content }: { content: SiteContent }) {
             <span className="ornament">✦</span> Current Series{' '}
             <span className="ornament">✦</span>
           </h2>
-          <div className="series-grid">
+          <div className={`series-grid${content.secondSeries?.title?.trim() ? ' series-grid--two' : ''}`}>
             {[
               {
                 key: 'primary',