refactor: Convert monolithic app to modular architecture

This commit refactors the entire codebase from a monolithic structure to a
modular one. Key changes include:

-   Extracting core components (e.g., user authentication, data processing,
    API handlers) into their own distinct modules.
-   Implementing a new directory structure to support a modular design.
-   Updating all internal references and import paths to reflect the new
    architecture.

The new structure improves maintainability, scalability, and allows for
easier independent development of each module in the future.

routes/contactRoutes.js

@@ -0,0 +1,42 @@
+const express = require('express');
+const router = express.Router();
+const rateLimit = require('express-rate-limit');
+const { body, validationResult } = require('express-validator');
+const contactController = require('../controllers/contactController');
+const { formSecurityCheck } = require('../middleware/securityMw');
+
+// 🛡️ Configure rate limiting to prevent DDoS and spamming
+const apiLimiter = rateLimit({
+    windowMs: 15 * 60 * 1000, // 15 minutes
+    max: 5,
+    message: "Too many requests from this IP, please try again after 15 minutes."
+});
+
+// Define the route for form submissions
+router.post('/submit-form',
+    apiLimiter,
+    [
+        // express-validator: sanitation and validation
+        body('firstName').trim().escape(),
+        body('lastName').trim().escape(),
+        body('email').isEmail().normalizeEmail(),
+        body('organization').trim().escape(),
+        body('phone').trim(),
+        body('message').trim().escape(),
+    ],
+    // Middleware to handle the express-validator results
+    (req, res, next) => {
+        const errors = validationResult(req);
+        if (!errors.isEmpty()) {
+            console.error('Validation failed:', errors.array());
+            return res.status(400).json({ success: false, message: 'Invalid form data.' });
+        }
+        next();
+    },
+    // The security middleware
+    formSecurityCheck,
+    // The controller, which is the final step
+    contactController.submitForm
+);
+
+module.exports = router;