M35: harden the shared public demo

frontend/nginx.conf

@@ -1,3 +1,6 @@
+limit_req_zone $binary_remote_addr zone=demo_login:10m rate=10r/m;
+limit_req_zone $binary_remote_addr zone=demo_reset:10m rate=2r/m;
+
 server {
   listen 80;
   server_name _;
@@ -5,6 +8,28 @@ server {
   root /usr/share/nginx/html;
   index index.html;
 
+  add_header X-Content-Type-Options "nosniff" always;
+  add_header X-Frame-Options "DENY" always;
+  add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+  add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), payment=()" always;
+  add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; font-src 'self'; connect-src 'self'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'" always;
+
+  location = /api/v1/demo/login {
+    limit_req zone=demo_login burst=5 nodelay;
+    proxy_pass http://api:8000;
+    proxy_set_header Host $host;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Proto $scheme;
+  }
+
+  location = /api/v1/demo/reset {
+    limit_req zone=demo_reset burst=1 nodelay;
+    proxy_pass http://api:8000;
+    proxy_set_header Host $host;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Proto $scheme;
+  }
+
   location /api/ {
     proxy_pass http://api:8000;
     proxy_set_header Host $host;
@@ -17,6 +42,12 @@ server {
   }
 
   location / {
+    expires -1;
     try_files $uri /index.html;
   }
+
+  location ~* ^/assets/.+\.[a-fA-F0-9_-]+\.(css|js|woff2|png|svg)$ {
+    expires 1y;
+    try_files $uri =404;
+  }
 }