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/test-zone-data/DNSSEC-TP/dnssec07/root-zone.zone

@@ -0,0 +1,32 @@
+$ORIGIN .
+$TTL 3600
+
+@                SOA     ns1. admin.xa. (
+                         2025100201      ; serial
+                         6h              ; refresh
+                         1h              ; retry
+                         1w              ; expire
+                         1d )            ; minimum
+
+                 NS     root-ns1.xa.
+                 NS     root-ns2.xa.
+                 TXT    "dnssec07"
+
+root-ns1.xa.     A      127.15.7.27
+root-ns1.xa.     AAAA   fda1:b2:c3::127:15:7:27
+
+root-ns2.xa.     A      127.15.7.28
+root-ns2.xa.     AAAA   fda1:b2:c3::127:15:7:28
+
+$ORIGIN dnssec07.xa.
+@                NS     ns1
+@                NS     ns2
+
+ns1              A      127.15.7.21
+ns1              AAAA   fda1:b2:c3::127:15:7:21
+ns2              A      127.15.7.22
+ns1              AAAA   fda1:b2:c3::127:15:7:22
+
+
+
+;EOF