fix: update deployment scripts to use dynamic DEPLOY_PATH for backend and frontend

frontend/ecosystem.config.js

@@ -3,6 +3,7 @@ module.exports = {
     name: 'portfolio-frontend',  // A name for your application in PM2
     script: 'npm',               // Tell PM2 to run an npm command
     args: 'start',               // The argument to pass to npm, which runs 'next start'
+    cwd: `${process.env.DEPLOY_PATH}/frontend`, // Current working directory for the script
     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