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-engine/t/Test-address03.t

@@ -0,0 +1,58 @@
+use strict;
+use warnings;
+
+use File::Basename;
+use File::Spec::Functions qw( rel2abs );
+use lib dirname( rel2abs( $0 ) );
+use TestUtil::DSL;
+
+testing_test_case 'Address', 'address03';
+
+all_tags qw(NAMESERVER_IP_PTR_MATCH
+            NAMESERVER_IP_PTR_MISMATCH
+            NAMESERVER_IP_WITHOUT_REVERSE
+            NO_RESPONSE_PTR_QUERY);
+
+# Common hint file (test-zone-data/COMMON/hintfile)
+root_hints 'ns1' => [ qw(127.1.0.1 fda1:b2:c3::127:1:0:1) ],
+           'ns2' => [ qw(127.1.0.2 fda1:b2:c3::127:1:0:2) ];
+
+zone_name_template '{SCENARIO}.{TESTCASE}.xa';
+
+# Test zone scenarios
+scenario 'ALL-NS-HAVE-PTR-{1..2}' => sub {
+    expect 'NAMESERVER_IP_PTR_MATCH';
+    forbid_others;
+};
+
+scenario 'NO-NS-HAVE-PTR' => sub {
+    expect 'NAMESERVER_IP_WITHOUT_REVERSE';
+    forbid_others;
+};
+
+scenario 'INCOMPLETE-PTR-{1..2}' => sub {
+    expect 'NAMESERVER_IP_WITHOUT_REVERSE';
+    forbid_others;
+};
+
+scenario 'NON-MATCHING-NAMES' => sub {
+    expect 'NAMESERVER_IP_PTR_MISMATCH';
+    forbid_others;
+};
+
+scenario 'PTR-IS-GOOD-CNAME-{1..2}' => sub {
+    expect 'NAMESERVER_IP_PTR_MATCH';
+    forbid_others;
+};
+
+scenario 'PTR-IS-DANGLING-CNAME' => sub {
+    expect 'NAMESERVER_IP_WITHOUT_REVERSE';
+    forbid_others;
+};
+
+scenario 'PTR-IS-ILLEGAL-CNAME' => sub {
+    expect 'NAMESERVER_IP_WITHOUT_REVERSE';
+    forbid 'NAMESERVER_IP_PTR_MATCH';
+};
+
+no_more_scenarios;