feat(config, layout, components): enhance security headers, improve SEO, and update project descriptions

- Added security headers in the Next.js configuration to enhance application security.
- Updated metadata in the layout component for improved SEO, including new titles, descriptions, and keywords.
- Introduced JSON-LD schema for projects to enhance search engine visibility.
- Enhanced project descriptions in the portfolio data for clarity and detail.
- Improved header component with logo integration and refined social media links for better accessibility.

app/robots.ts

@@ -0,0 +1,14 @@
+import { MetadataRoute } from 'next'
+
+export default function robots(): MetadataRoute.Robots {
+  return {
+    rules: [
+      {
+        userAgent: '*',
+        allow: '/',
+        disallow: ['/api/', '/_next/', '/admin/'],
+      },
+    ],
+    sitemap: 'https://evandro.dev.br/sitemap.xml',
+  }
+}