feat: implement deployment workflow and configure PM2 for backend and frontend applications

backend/ecosystem.config.js

@@ -0,0 +1,13 @@
+module.exports = {
+  apps: [{
+    name: 'portfolio-backend', // A name for your application in PM2
+    script: 'server.js',      // The path to the script PM2 will run
+    instances: 1,             // Run a single instance of the application
+    autorestart: true,        // Automatically restart if the app crashes
+    watch: false,             // Do NOT watch for file changes in production
+    max_memory_restart: '256M', // Restart if it uses more than 256MB of RAM
+    env: {
+      NODE_ENV: 'production', // Set the environment to production
+    }
+  }]
+};