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/utils/generateTestMessages.pl

@@ -0,0 +1,36 @@
+#!/usr/bin/env perl
+
+use 5.16.0;
+use warnings;
+use Zonemaster::Engine;
+use File::Basename;
+
+# page header
+print '<!-- File generated by ', basename ($0), ", script in zonemaster/zonemaster util directory.\n";
+print "Use that script to generate a new file for each release of Zonemaster when \n";
+print "Zonemaster-Engine also has been updated.-->\n\n";
+print "# Mapping test messages to Test Cases\n\n";
+print "Index of Text Cases are found in [README](README.md).\n\n";
+
+# table header
+print "| Message tag from [Zonemaster-Engine] | Module | Method (implemented test case) |\n";
+print "|:-------------------------------------|:-------|:-------------------------------|\n";
+
+# table content
+foreach my $module ( sort { fc $a cmp fc $b } Zonemaster::Engine::Test->modules ) {
+    my $full = "Zonemaster::Engine::Test::$module";
+    my $ref  = $full->metadata;
+    for my $key (sort keys %$ref) {
+        my $list = $ref->{$key};
+        for my $tag (sort { $a cmp $b } @$list) {
+            my $testlevel = "${module}-TP";
+	    my $testlevellink = "$module-TP/README.md";
+            my $testcasefile = "$key.md";
+            my $testcaselink = "$testlevel/$testcasefile";
+            printf "| %-40s | [%s](%s) | [%s](%s) |\n", $tag, $module, $testlevellink, $key, $testcaselink;
+        }
+    }
+}
+
+print "\n[Zonemaster-Engine]: https://github.com/zonemaster/zonemaster-engine\n";
+