Update environment variables and add flatpickr dependency

app.js

@@ -103,14 +103,19 @@ app.get('/', (req, res) => {
 });
 
 const isPassengerRuntime = typeof global.PhusionPassenger !== 'undefined';
+const logStartup = (runtime, host) => {
+    const startedAt = new Date().toISOString();
+    const user = process.env.USER || process.env.LOGNAME || 'unknown';
+    console.log(`[${startedAt}] Servidor corriendo en ${host} runtime=${runtime} pid=${process.pid} user=${user}`);
+};
 
 if (isPassengerRuntime) {
     app.listen('passenger', () => {
-        console.log('Servidor corriendo bajo Passenger');
+        logStartup('passenger', 'passenger');
     });
 } else if (require.main === module) {
     app.listen(PORT, "127.0.0.1", () => {
-        console.log(`Servidor corriendo en puerto ${PORT}`);
+        logStartup('node', `127.0.0.1:${PORT}`);
     });
 }