Improve server startup logging and update script fetching (#443)

Adds success and error logging to the Next.js app preparation process in server.js, including guidance for missing production builds. In versionRouter, always fetches the latest update.sh from GitHub before running updates, logging the outcome and falling back to the local script if fetching fails.

server.js

@@ -1610,6 +1610,7 @@ class ScriptExecutionHandler {
 // TerminalHandler removed - not used by current application
 
 app.prepare().then(() => {
+  console.log('> Next.js app prepared successfully');
   const httpServer = createServer(async (req, res) => {
     try {
       // Be sure to pass `true` as the second argument to `url.parse`.
@@ -1715,4 +1716,9 @@ app.prepare().then(() => {
         autoSyncModule.setupGracefulShutdown();
       }
     });
+}).catch((err) => {
+  console.error('> Failed to start server:', err.message);
+  console.error('> If you see "Could not find a production build", run: npm run build');
+  console.error('> Full error:', err);
+  process.exit(1);
 });