Add banner, Apple Podcasts link, feed proxy, and fetch retry

- Add roostbanner.png hero banner image
- Add Apple Podcasts subscribe button
- Add Cloudflare Pages Function to proxy RSS feed (avoids CORS)
- Add fetch timeout and retry for episode loading
- Add contact email to footer
- Replace favicon with inline SVG rooster

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

website/css/style.css

@@ -33,6 +33,18 @@ a:hover {
   color: var(--accent-hover);
 }
 
+/* Banner */
+.banner {
+  width: 100%;
+  overflow: hidden;
+}
+
+.banner-img {
+  width: 100%;
+  height: auto;
+  display: block;
+}
+
 /* Hero */
 .hero {
   padding: 3rem 1.5rem 2rem;
@@ -356,6 +368,18 @@ a:hover {
   color: var(--text);
 }
 
+.footer-contact {
+  margin-bottom: 0.75rem;
+}
+
+.footer-contact a {
+  color: var(--accent);
+}
+
+.footer-contact a:hover {
+  color: var(--accent-hover);
+}
+
 /* Desktop */
 @media (min-width: 768px) {
   .hero {