refactor: remove security headers from nginx configuration

nginx.conf

@@ -4,13 +4,6 @@ server {
     root /usr/share/nginx/html;
     index index.html;
 
-    # Security headers
-    add_header X-XSS-Protection "1; mode=block";
-    add_header X-Content-Type-Options "nosniff";
-    add_header X-Frame-Options "SAMEORIGIN";
-    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline';";
-    add_header Referrer-Policy "strict-origin-when-cross-origin";
-
     location / {
         try_files $uri $uri/ /index.html;
     }