Enhance security and localization features across the application

- Added rehype-sanitize plugin to the markdown configuration for improved security against XSS attacks.
- Updated environment variables in the codebase to include new configurations for SMTP and monitoring.
- Implemented secure headers in server and Nginx configurations to bolster security.
- Refactored email handling to prevent spoofing by ensuring safe sender addresses.
- Improved localization by updating language persistence and button components for better user experience.
- Enhanced the uptime API and contact form with better error handling and logging practices.
- Updated dependencies in package.json and package-lock.json for better performance and security.

src/middleware.ts

@@ -3,7 +3,8 @@ import { defineMiddleware } from 'astro:middleware';
 export const onRequest = defineMiddleware(async (context, next) => {
   // Only redirect if we're at the root path
   if (context.url.pathname === '/') {
-    return context.redirect('/en', 301);
+    // Use 302 to avoid permanent redirect caching during content negotiation
+    return context.redirect('/en', 302);
   }
   
   return next();