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/Makefile.PL

@@ -0,0 +1,84 @@
+use inc::Module::Install;
+use Module::Install::Share;
+
+name 'Zonemaster-Engine';
+# "name" must be the same as the equivalent string in the following files:
+# lib/Zonemaster/Engine/Constants.pm
+# lib/Zonemaster/Engine/Config.pm
+# lib/Zonemaster/Engine/Translator.pm
+# share/Makefile
+
+
+repository 'https://github.com/zonemaster/zonemaster-engine';
+bugtracker 'https://github.com/zonemaster/zonemaster-engine/issues';
+
+all_from 'lib/Zonemaster/Engine.pm';
+
+# "2.1.0" could be declared as "2.001" but not as "2.1"
+# (see Zonemaster::LDNS below)
+
+requires 'Class::Accessor'    => 0;
+requires 'Clone'              => 0;
+requires 'Email::Valid'       => 0;
+requires 'File::ShareDir'     => 1.00;
+requires 'File::Slurp'        => 0;
+requires 'IO::Socket::INET6'  => 2.69;
+requires 'List::Compare'      => 0;
+requires 'List::MoreUtils'    => 0;
+requires 'Locale::TextDomain' => 1.20;
+requires 'Log::Any'           => 0;
+requires 'Mail::SPF'          => 0;
+requires 'Module::Find'       => 0.10;
+requires 'Net::DNS'           => 0;
+requires 'Net::IP::XS'        => 0.21;
+requires 'Readonly'           => 0;
+requires 'Text::CSV'          => 0;
+requires 'YAML::XS'           => 0;
+requires 'Zonemaster::LDNS'   => 5.000002; # For v5.0.2
+
+test_requires 'Locale::PO'        => 0;
+test_requires 'Pod::Coverage'     => 0;
+test_requires 'Sub::Override'     => 0;
+test_requires 'Test::Differences' => 0;
+test_requires 'Test::Exception'   => 0;
+test_requires 'Test::Fatal'       => 0;
+test_requires 'Test::NoWarnings'  => 0;
+test_requires 'Test::Pod'         => 1.22;
+
+# Make all platforms include inc/Module/Install/External.pm
+requires_external_bin 'find';
+if ($^O eq "freebsd") {
+    requires_external_bin 'gmake';
+};
+
+sub MY::postamble {
+    my $pure_all;
+    if ($^O eq "freebsd") {
+        # Make FreeBSD use gmake for share/Makefile
+        $pure_all = 'GMAKE ?= "gmake"' . "\n"
+            . 'pure_all :: share/Makefile' . "\n"
+            . "\t" . 'cd share && $(GMAKE) all' . "\n";
+    } else {
+        $pure_all = 'pure_all :: share/Makefile' . "\n"
+            . "\t" . 'cd share && $(MAKE) all' . "\n";
+    }
+
+    my $docker = <<'END_DOCKER';
+
+docker-build:
+	docker build --tag zonemaster/engine:local --build-arg version=$(VERSION) .
+
+docker-tag-version:
+	docker tag zonemaster/engine:local zonemaster/engine:$(VERSION)
+
+docker-tag-latest:
+	docker tag zonemaster/engine:local zonemaster/engine:latest
+
+END_DOCKER
+
+    return $pure_all . $docker;
+};
+
+install_share;
+
+WriteAll;