feat: lightweight static PCA Lab site with domain groups

Replace Next.js scanner deploy with static React CDN pages: student
VPN cabinet, regional setup, curated blocked-domain lists, and nginx
one-line install on port 80 without touching Amnezia/Docker services.

Co-authored-by: Cursor <cursoragent@cursor.com>

nginx/domain-web.conf

@@ -0,0 +1,24 @@
+# PCA Lab / Domain Web — static site on port 80
+# Installed to /etc/nginx/sites-available/domain-web
+
+server {
+    listen 80 default_server;
+    listen [::]:80 default_server;
+    server_name _;
+
+    root /var/www/domain-web;
+    index index.html;
+
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    location ~* \.(json|jsx|html|css|js|png|jpg|svg|ico|woff2?)$ {
+        expires 1h;
+        add_header Cache-Control "public";
+    }
+
+    # Do not proxy — Amnezia and other services stay on 443 separately
+    access_log /var/log/nginx/domain-web-access.log;
+    error_log /var/log/nginx/domain-web-error.log;
+}