Add root status route

app/src/server.js

@@ -95,6 +95,10 @@ app.get('/health', (req, res) => {
   res.json({ status: 'ok', plan: PLAN });
 });
 
+app.get('/', (req, res) => {
+  res.status(200).send('Capay API online. Use /health for status.');
+});
+
 app.post('/merchants', async (req, res) => {
   const { name, email, webhookUrl } = req.body || {};
   if (!name || !email) {