Add Spotify podcast embed to home page

src/App.tsx

@@ -1115,6 +1115,24 @@ function HomePage({
         </div>
       </section>
 
+      <section className="podcast home-block" aria-label="Podcast embed">
+        <h2>Podcast</h2>
+        <div className="embed-frame" style={{ margin: '0 auto', maxWidth: '760px' }}>
+          <iframe
+            data-testid="embed-iframe"
+            title="Titus Study Podcast"
+            style={{ borderRadius: '12px' }}
+            src="https://open.spotify.com/embed/show/0Gq1TzoJOdReSZ1gYQi8Xl?utm_source=generator"
+            width="100%"
+            height="352"
+            frameBorder="0"
+            allowFullScreen
+            allow="autoplay; clipboard-write; encrypted-media; fullscreen; picture-in-picture"
+            loading="lazy"
+          />
+        </div>
+      </section>
+
       {siteContent.showSidebar ? (
         <div className="home-layout">
           <div className="home-main">{mainSections.map((section) => renderHomeSection(section.id))}</div>