Integrate dotenv for environment variable management and enhance form error handling

- Added dotenv to load environment variables from a .env file in server.js for better configuration management.
- Improved the Form component by refining error handling during form submission, including specific messages for different error scenarios.
- Updated the CSRF token handling and ensured proper validation of response types from the contact API.
- Enhanced user feedback by providing clearer messages for success and error states in the form submission process.

server.js

@@ -1,3 +1,7 @@
+// Load environment variables from .env file first
+import dotenv from 'dotenv';
+dotenv.config();
+
 import express from 'express';
 import compression from 'compression';
 import { handler } from './dist/server/entry.mjs';