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/docs/internal/design/README.md

@@ -0,0 +1,28 @@
+# README
+
+## Overview
+
+This directory contains documentation relating to the architecture of the
+Zonemaster components and how they interact to achieve the desired result.
+
+
+## Contents
+
+ * [Architecture Notes.md]  
+   TBD
+
+ * [Implementation Guidelines.md]  
+   TBD
+
+ * [Profiles.md]  
+   Profiles is a configuration format and feature of Zonemaster Engine.
+   Each of Zonemaster CLI, Backend and GUI allow users and administrators to configure Zonemaster Engine with different profiles.
+
+ * [Versions and Releases.md]  
+   TBD
+
+
+[Architecture Notes.md]: Architecture%20Notes.md
+[Implementation Guidelines.md]: Implementation%20Guidelines.md
+[Profiles.md]: Profiles.md
+[Versions and Releases.md]: Versions%20and%20Releases.md