Add auto-generated RSS feed with scheduled publishing support

- Created /rss.xml API route that generates valid RSS 2.0 XML
- RSS feed integrates with scheduled publishing system automatically
- Includes full post content, proper metadata, and CDATA encoding
- Added RSS feed link to HTML metadata for auto-discovery
- RSS link already exists in blog footer navigation
- 1-hour caching with error handling and fallback RSS
- Feed updates automatically when new posts go live

Features:
✅ Works with scheduled posts (future posts excluded)
✅ Proper XML escaping and CDATA content encoding
✅ Rich metadata including author, categories, publish dates
✅ Auto-discovery via HTML <link> tags
✅ Graceful error handling with fallback feed

🤖 Generated with [Claude Code](https://claude.ai/code)

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

app/layout.tsx

@@ -25,6 +25,11 @@ export const metadata: Metadata = {
   metadataBase: new URL('https://blog.chorus.services'),
   alternates: {
     canonical: 'https://blog.chorus.services',
+    types: {
+      'application/rss+xml': [
+        { url: '/rss.xml', title: 'CHORUS PING! RSS Feed' }
+      ]
+    }
   },
   openGraph: {
     type: 'website',