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/COMMON/root-zone

@@ -0,0 +1,83 @@
+$ORIGIN .
+$TTL 3600
+
+@       SOA     ns1. admin.xb. (
+                2022112300      ; serial
+                6h              ; refresh
+                1h              ; retry
+                1w              ; expire
+                1d )            ; minimum
+
+          NS     ns1.
+          NS     ns2.
+
+ns1.      A      127.1.0.1
+ns1.      AAAA   fda1:b2:c3::127:1:0:1
+
+ns2.      A       127.1.0.2
+ns2.      AAAA    fda1:b2:c3::127:1:0:2
+
+arpa.     NS      ns1.
+arpa.     NS      ns2.
+
+xa.       NS      ns1.xa.
+ns1.xa.   A       127.2.0.11
+ns1.xa.   AAAA    fda1:b2:c3::127:2:0:11
+
+xa.       NS      ns2.xa.
+ns2.xa.   A       127.2.0.12
+ns2.xa.   AAAA    fda1:b2:c3::127:2:0:12
+
+$ORIGIN xb.       
+@         NS      ns1
+@         NS      ns2
+ns1       A       127.2.0.13
+ns1       AAAA    fda1:b2:c3::127:2:0:13
+ns2       A       127.2.0.14
+ns2       AAAA    fda1:b2:c3::127:2:0:14
+
+$ORIGIN tld-email-domain-zone09.
+@         NS     ns1
+@         NS     ns2
+ns1       A      127.19.9.41
+ns1       AAAA   fda1:b2:c3::127:19:9:41
+ns2       A      127.19.9.42
+ns2       AAAA   fda1:b2:c3::127:19:9:42
+
+asnlookup.zonemaster.net.       NS     ns2.asnlookup.zonemaster.net.
+asnlookup.zonemaster.net.       NS     ns1.asnlookup.zonemaster.net.
+ns1.asnlookup.zonemaster.net.   A      127.3.0.1
+ns2.asnlookup.zonemaster.net.   A      127.3.0.2
+
+; ZONE09
+$ORIGIN tld-email-domain-zone09.
+@                               NS     ns1
+@                               NS     ns2
+ns1                             A      127.19.9.41
+ns1                             AAAA   fda1:b2:c3::127:19:9:41
+ns2                             A      127.19.9.42
+ns2                             AAAA   fda1:b2:c3::127:19:9:42
+
+; ZONE11
+$ORIGIN no-spf-zone11.
+@                               NS     ns1.zone11.xa.
+@                               NS     ns2.zone11.xa.
+
+$ORIGIN null-spf-zone11.
+@                               NS     ns1.zone11.xa.
+@                               NS     ns2.zone11.xa.
+
+$ORIGIN non-null-spf-zone11.
+@                               NS     ns1.zone11.xa.
+@                               NS     ns2.zone11.xa.
+
+; DNSSEC03
+$ORIGIN nsec3-opt-out-enabled-tld-dnssec03.
+@                               NS     ns1
+@                               NS     ns2
+ns1                             A      127.15.3.31
+ns1                             AAAA   fda1:b2:c3:0:127:15:3:31
+ns2                             A      127.15.3.32
+ns2                             AAAA   fda1:b2:c3:0:127:15:3:32
+
+;EOF