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/Delegation-TP/README.md

@@ -0,0 +1,21 @@
+# Delegation Test Plan
+
+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|
+|:---------|:--------------------|
+|[DELEGATION01](delegation01.md)|Minimum number of name servers   |
+|[DELEGATION02](delegation02.md)|Name servers must have distinct IP addresses|
+|[DELEGATION03](delegation03.md)|No truncation of referrals|
+|[DELEGATION04](delegation04.md)|Name server is authoritative|
+|[DELEGATION05](delegation05.md)|Name server must not point at CNAME alias|
+|[DELEGATION06](delegation06.md)|Existence of SOA|
+|[DELEGATION07](delegation07.md)|Parent glue name records present in child|