feat: сборка в nginx и режим превью (noindex, без контактов)

refs breazu/breazu#2

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,4 @@
+FROM nginx:1.30-alpine
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY index.html report.html robots.txt /usr/share/nginx/html/
+COPY assets /usr/share/nginx/html/assets