feat: Racing Cards landing page - Astro + Tailwind v4

- Mobile-first dark mode landing
- Lucide icons (zero emojis)
- Self-hostable (Dockerfile + nginx)
- 10 card images generated with Nano Banana 2
- Sections: Hero, How It Works, Card Gallery, Features, Early Access, Footer
- Simple HTML form (no Netlify dependency)
- Zero JS output, static HTML

nginx.conf

@@ -0,0 +1,27 @@
+server {
+    listen 80;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Security headers
+    add_header X-Frame-Options "DENY" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+
+    # Cache static assets
+    location /_astro/ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    # SPA fallback
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Gzip
+    gzip on;
+    gzip_types text/plain text/css application/javascript application/json image/svg+xml;
+    gzip_min_length 256;
+}