Add logo image and update branding across header, footer, and emails

- Replace text logo with logo-spanglish.png in Header and Footer
- Update email templates to use logo image instead of styled text
- Add new HeroSection and EventHighlight components
- Update homepage layout and event detail pages
- Adjust Tailwind config and global styles

frontend/src/app/(public)/components/NewsletterSection.tsx

@@ -0,0 +1,26 @@
+'use client';
+
+import { useLanguage } from '@/context/LanguageContext';
+import { SparklesIcon } from '@heroicons/react/24/outline';
+import NewsletterForm from './NewsletterForm';
+
+export default function NewsletterSection() {
+  const { t } = useLanguage();
+
+  return (
+    <section className="section-padding bg-primary-dark text-white">
+      <div className="container-page">
+        <div className="max-w-2xl mx-auto text-center">
+          <SparklesIcon className="w-12 h-12 mx-auto text-primary-yellow" />
+          <h2 className="mt-6 text-3xl md:text-4xl font-bold">
+            {t('home.newsletter.title')}
+          </h2>
+          <p className="mt-4 text-gray-300">
+            {t('home.newsletter.description')}
+          </p>
+          <NewsletterForm />
+        </div>
+      </div>
+    </section>
+  );
+}