feat: add full Zonemaster stack with Docker and Spanish UI

- Clone all 5 Zonemaster component repos (LDNS, Engine, CLI, Backend, GUI)
- Dockerfile.backend: 8-stage multi-stage build LDNS→Engine→CLI→Backend
- Dockerfile.gui: Astro static build served via nginx
- docker-compose.yml: backend (internal) + frontend (port 5353)
- nginx.conf: root redirects to /es/, /api/ proxied to backend
- zonemaster-gui/config.ts: defaultLanguage set to 'es' (Spanish)

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

zonemaster-gui/zonemaster.conf-example

@@ -0,0 +1,57 @@
+<VirtualHost *:80>
+
+    # BASE_URL can be set and DEFAULT_LANGUAGE can be updated.
+
+    # Uncomment the following line *only* if the GUI is served from a
+    # subdirectory. The setting here must match the setting in config.ts.
+    # Must start with a slash, but not end with a slash.
+    # Define BASE_URL "/subdirectory" # Undefined by default
+
+    # Default language must be updated if "defaultLanguage" in config.ts is
+    # changed. Both must match.
+    Define DEFAULT_LANGUAGE "en"
+
+
+    # Nothing to set or update below. #
+
+    DirectoryIndex index.html
+
+    <IfDefine BASE_URL>
+        Alias ${BASE_URL} /var/www/html/zonemaster-web-gui/dist
+        Define API_BASE_URL "${BASE_URL}/api"
+    </IfDefine>
+
+    <IfDefine !BASE_URL>
+        DocumentRoot /var/www/html/zonemaster-web-gui/dist
+        Define API_BASE_URL "/api"
+    </IfDefine>
+
+    <Directory /var/www/html/zonemaster-web-gui/dist>
+        Options Indexes FollowSymLinks
+        AllowOverride None
+        Require all granted
+
+        RewriteEngine On
+        <IfDefine BASE_URL>
+            RewriteBase ${BASE_URL}/
+        </IfDefine>
+
+        RewriteRule ^$ /${DEFAULT_LANGUAGE} [R]
+
+        # Rewrite /result/{anything} to {default_language}/result/id/index.html
+        RewriteCond %{REQUEST_FILENAME} !-f
+        RewriteCond %{REQUEST_FILENAME} !-d
+        RewriteRule ^result/[^/]+/?$ ${DEFAULT_LANGUAGE}/result/id/index.html [L]
+
+        # Rewrite /{lang}/result/{anything} to /{lang}/result/id/index.html
+        RewriteCond %{REQUEST_FILENAME} !-f
+        RewriteCond %{REQUEST_FILENAME} !-d
+        RewriteRule ^([^/]+)/result/[^/]+/?$ $1/result/id/index.html [L]
+    </Directory>
+
+    <Location "${API_BASE_URL}">
+        ProxyPass http://localhost:5000/
+        ProxyPassReverse http://localhost:5000/
+        ProxyPreserveHost On
+    </Location>
+</VirtualHost>