feat: Astro Starlight Docs-Site für BTC MAIN AI Application Layer

Vollständige Dokumentations-Site mit:
- Einstieg: Einführung, Schnellstart, Kernkonzepte
- Guides: Deployment, CI/CD, Env-Vars, Domains, Logs
- API-Referenz: Überblick, Auth, Applications, Deployments
- Referenz: Tech Stack, FAQ
- Dockerfile + nginx für containerisiertes Deployment

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nginx.conf

@@ -0,0 +1,32 @@
+server {
+    listen 80;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    location / {
+        try_files $uri $uri/ $uri.html $uri/index.html =404;
+    }
+
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot|webp|avif)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    location ~* \.html$ {
+        add_header Cache-Control "no-cache, must-revalidate";
+    }
+
+    gzip on;
+    gzip_vary on;
+    gzip_types
+        text/plain
+        text/css
+        text/javascript
+        application/javascript
+        application/json
+        image/svg+xml;
+
+    add_header X-Frame-Options "SAMEORIGIN";
+    add_header X-Content-Type-Options "nosniff";
+    add_header Referrer-Policy "strict-origin-when-cross-origin";
+}