feat(docker): containerize sag24.ru — multi-stage Next.js build + nginx/php-fpm runtime

Single-container approach (nginx + php-fpm 8.3 + supervisord) to match web.hhivp.com
deployment paradigm (host nginx → docker по порту).

- Dockerfile: builder (node:22-alpine npm ci+next build) → runtime (php:8.3-fpm-alpine)
- docker/nginx.conf: serves static from /var/www/sag24.ru/public_html, fastcgi_pass на 127.0.0.1:9000
- docker/supervisord.conf: запускает php-fpm + nginx
- docker-compose.yml: для деплоя на web в /opt/docker/sites/sag24-ru/, mount contact-config.php read-only
- .dockerignore: исключает node_modules/.git/out из контекста

Container exposes :8080 (бесроутовый bind), маппится на host :4070 на web.
Watchtower label включён (auto-deploy на изменения образа в registry).

docker/nginx.conf

@@ -0,0 +1,62 @@
+worker_processes auto;
+error_log /dev/stderr warn;
+pid /run/nginx/nginx.pid;
+
+events {
+    worker_connections 1024;
+}
+
+http {
+    include /etc/nginx/mime.types;
+    default_type application/octet-stream;
+
+    sendfile on;
+    tcp_nopush on;
+    keepalive_timeout 30;
+    server_tokens off;
+
+    # Доверять X-Forwarded-For от host nginx на web (loopback proxy).
+    set_real_ip_from 127.0.0.1/32;
+    set_real_ip_from 172.16.0.0/12;
+    real_ip_header X-Forwarded-For;
+    real_ip_recursive on;
+
+    log_format main '$remote_addr - $remote_user [$time_local] '
+                    '"$request" $status $body_bytes_sent '
+                    '"$http_referer" "$http_user_agent"';
+    access_log /dev/stdout main;
+
+    gzip on;
+    gzip_types text/plain text/css application/javascript application/json image/svg+xml;
+    gzip_min_length 1024;
+    gzip_vary on;
+
+    server {
+        listen 8080 default_server;
+        server_name _;
+
+        root /var/www/sag24.ru/public_html;
+        index index.html;
+
+        # Старые URL без локали → /ru/
+        rewrite ^/uslugi(/.*)?$ /ru/uslugi$1 redirect;
+
+        location ~ ^/api/.*\.php$ {
+            try_files $uri =404;
+            fastcgi_pass 127.0.0.1:9000;
+            fastcgi_index contact.php;
+            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
+            include fastcgi_params;
+        }
+
+        location = /robots.txt {
+            log_not_found off;
+            access_log off;
+        }
+
+        error_page 404 /404.html;
+        location / {
+            try_files $uri $uri/ $uri/index.html =404;
+        }
+    }
+}