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/public/specifications/tests/Address-TP/README.md

@@ -0,0 +1,19 @@
+# Address Test Plan
+
+These tests focus on the Address specific test cases of the DNS tests.
+
+This document uses the terminology defined in the [Master Test Plan].
+
+
+[Master Test Plan]:             ../MasterTestPlan.md
+[Test Case README]:             ../README.md
+
+<!-- Content until EOF generated by script updateTestPlanReadme.pl from Zonemaster/Zonemaster utils directory -->
+
+## Test cases list
+
+|Test Case |Test Case Description|
+|:---------|:--------------------|
+|[ADDRESS01](address01.md)|Name server address must be globally reachable|
+|[ADDRESS02](address02.md)|Reverse DNS entry exists for name server IP address|
+|[ADDRESS03](address03.md)|Reverse DNS entry matches name server name|