Add public/private news system with homepage display

server/utils/news.js

@@ -69,6 +69,7 @@ export async function saveNews(newsData) {
     const newItem = {
       ...newsData,
       id: randomUUID(), // Cryptographically secure unique ID
+      isPublic: newsData.isPublic || false, // Default to internal
       created: new Date().toISOString(),
       updated: new Date().toISOString()
     }