refactor: Remove hardcoded values from codebase, converting to environment variables

server.js

@@ -5,13 +5,14 @@ const { Pool } = require('pg');
 const rateLimit = require('express-rate-limit');
 require('dotenv').config();
 const app = express();
-const port = 3000;
+const port = process.env.SERVER_PORT || 3000;
 
 // Middleware to parse incoming JSON data from the frontend
 app.use(express.json());
 
 // Middleware to serve static files (like index.html, styles.css, script.js)
-app.use(express.static(path.join(__dirname, 'public')));
+const STATIC_DIR = process.env.STATIC_DIR || 'public'
+app.use(express.static(path.join(__dirname, STATIC_DIR)));
 
 // Database connection pool setup using environment variables for security
 const pool = new Pool({
@@ -24,8 +25,8 @@ const pool = new Pool({
 
 // Nodemailer transporter setup for sending emails
 const transporter = nodemailer.createTransport({
-    host: 'smtp-relay.brevo.com',
-    port: 2525,
+    host: process.env.EMAIL_HOST,
+    port: process.env.EMAIL_PORT,
     secure: false,
     requireTLS: true,
     auth: {