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>

docker-compose.yml

@@ -0,0 +1,23 @@
+services:
+  backend:
+    build:
+      context: .
+      dockerfile: Dockerfile.backend
+    restart: unless-stopped
+    volumes:
+      - zonemaster-data:/var/lib/zonemaster
+      - zonemaster-logs:/var/log/zonemaster
+
+  frontend:
+    build:
+      context: .
+      dockerfile: Dockerfile.gui
+    ports:
+      - "5353:80"
+    depends_on:
+      - backend
+    restart: unless-stopped
+
+volumes:
+  zonemaster-data:
+  zonemaster-logs: