fix: Восстановлена генерация sitemap.xml

- Добавлен плагин автогенерации sitemap при сборке frontend
- Обновлен nginx.conf для fallback на backend sitemap
- Sitemap включает русские и английские версии всех страниц
- Поддержка hreflang для SEO

ospabhost/nginx.conf

@@ -168,13 +168,34 @@ server {
     # Robots.txt
     location = /robots.txt {
         access_log off;
-        try_files $uri =404;
+        try_files $uri @backend_robots;
     }
     
-    # Sitemap
+    # Sitemap - try static first, then backend
     location = /sitemap.xml {
         access_log off;
-        try_files $uri =404;
+        add_header Content-Type application/xml;
+        try_files $uri @backend_sitemap;
+    }
+    
+    # Fallback to backend for robots.txt
+    location @backend_robots {
+        proxy_pass https://backend_api/robots.txt;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+    
+    # Fallback to backend for sitemap
+    location @backend_sitemap {
+        proxy_pass https://backend_api/sitemap.xml;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
     }
     
     # Custom error page handler