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/.gitignore

@@ -0,0 +1,20 @@
+# Backup files from editor
+*.bak
+*~
+.*.swp
+
+# macOS attribute file
+.DS_Store
+
+# Ignore output by mdbook
+docs/public/book
+
+# Files generated by Bind (named)
+**/Bind/managed-keys.bind*
+**/Bind/named.pid
+**/Bind/*.mkeys*
+**/Bind/*/*.zone.signed
+**/Bind/*/*.jbk
+**/Bind/*/*.jnl
+**/Bind/key-dir/*
+**/Bind/key-dir-var1/*