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/main.cfg

@@ -0,0 +1,90 @@
+# This is the main coredns configuration to be loaded
+
+# root-zone on two servers
+. {
+    bind 127.1.0.1
+    bind fda1:b2:c3::127:1:0:1
+    file COMMON/root-zone . 
+    file COMMON/arpa arpa
+}
+
+. {
+    bind 127.1.0.2
+    bind fda1:b2:c3::127:1:0:2
+    file COMMON/root-zone .
+    file COMMON/arpa arpa
+}
+
+# internal resolver on one server
+. {
+    bind 127.3.0.53
+    unbound {
+       option root-hints COMMON/hintfile
+    }
+    log
+}
+
+# .xa on two servers
+# ns1.xa:
+xa. {
+    bind 127.2.0.11
+    bind fda1:b2:c3::127:2:0:11
+    file COMMON/xa xa
+}
+# ns2.xa:
+xa. {
+    bind 127.2.0.12
+    bind fda1:b2:c3::127:2:0:12
+    file COMMON/xa xa
+}
+
+# .xb on two servers
+# ns1.xb:
+xb. {
+    bind 127.2.0.13
+    bind fda1:b2:c3::127:2:0:13
+    file COMMON/xb xb
+}
+# ns2.xb:
+xb. {
+    bind 127.2.0.14
+    bind fda1:b2:c3::127:2:0:14
+    file COMMON/xb xb
+}
+
+# Include test case specific configuration
+#
+# Address-TP
+import Address-TP/address01/address01.cfg
+import Address-TP/address03/address03.cfg
+# Basic-TP
+import Basic-TP/basic01/basic01.cfg
+import Basic-TP/basic02/basic02.cfg
+# Connectivity-TP
+import Connectivity-TP/connectivity04/connectivity04.cfg
+# Consistency-TP
+import Consistency-TP/consistency05/consistency05.cfg
+import Consistency-TP/consistency06/consistency06.cfg
+# Delegation-TP
+import Delegation-TP/delegation01/delegation01.cfg
+import Delegation-TP/delegation02/delegation02.cfg
+import Delegation-TP/delegation03/delegation03.cfg
+# DNSSEC-TP
+import DNSSEC-TP/dnssec01/dnssec01.cfg
+import DNSSEC-TP/dnssec03/dnssec03.cfg
+import DNSSEC-TP/dnssec05/dnssec05.cfg
+import DNSSEC-TP/dnssec07/dnssec07.cfg
+import DNSSEC-TP/dnssec10/dnssec10.cfg
+import DNSSEC-TP/dnssec16/dnssec16.cfg
+# Nameserver-TP
+import Nameserver-TP/nameserver15/nameserver15.cfg
+# Zone-TP
+import Zone-TP/zone09/zone09.cfg
+import Zone-TP/zone11/zone11.cfg
+
+# Other
+#
+# Methods
+import MethodsV2/methodsv2.cfg
+# Engine
+import Engine/Recursor-PM/recursor.cfg