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-nameserver01-C.t

@@ -0,0 +1,37 @@
+use Test::More;
+
+BEGIN {
+    use_ok( q{Zonemaster::Engine} );
+    use_ok( q{Zonemaster::Engine::Test::Nameserver} );
+    use_ok( q{Zonemaster::Engine::Util} );
+}
+
+my $datafile = q{t/Test-nameserver01-C.data};
+
+if ( not $ENV{ZONEMASTER_RECORD} ) {
+    die q{Stored data file missing} if not -r $datafile;
+    Zonemaster::Engine::Nameserver->restore( $datafile );
+    Zonemaster::Engine->profile->set( q{no_network}, 1 );
+}
+
+Zonemaster::Engine->add_fake_delegation(
+    'c.nameserver01.exempelvis.se' => {
+        'ns1.c.nameserver01.exempelvis.se' => [ '46.21.97.97',    '2a02:750:12:77::97' ],
+        'ns2.c.nameserver01.exempelvis.se' => [ '194.18.226.122', '2001:2040:2b:1c13::53' ],
+    },
+    fill_in_empty_oob_glue => 0,
+);
+
+my $zone = Zonemaster::Engine->zone( q{c.nameserver01.exempelvis.se} );
+
+my %res = map { $_->tag => $_ } Zonemaster::Engine::Test::Nameserver->nameserver01( $zone );
+
+ok( !$res{NO_RESPONSE},   q{should not emit NO_RESPONSE} );
+ok( !$res{IS_A_RECURSOR}, q{should not emit IS_A_RECURSOR} );
+ok( $res{NO_RECURSOR},    q{should emit NO_RECURSOR} );
+
+if ( $ENV{ZONEMASTER_RECORD} ) {
+    Zonemaster::Engine::Nameserver->save( $datafile );
+}
+
+done_testing;