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-ldns/Dockerfile

@@ -0,0 +1,39 @@
+FROM alpine:3.22 as build
+
+RUN apk add --no-cache \
+    # Compile-time dependencies
+    build-base \
+    libidn2-dev \
+    make \
+    openssl-dev \
+    perl-app-cpanminus \
+    perl-dev \
+    perl-devel-checklib \
+    perl-extutils-depends \
+    perl-extutils-pkgconfig \
+    perl-lwp-protocol-https \
+    perl-mime-base32 \
+    perl-module-install \
+    perl-test-differences \
+    perl-test-fatal \
+    perl-test-nowarnings \
+ && cpanm --notest --no-wget --from=https://cpan.metacpan.org/ \
+    Module::Install::XSUtil
+
+ARG version
+
+COPY ./Zonemaster-LDNS-${version}.tar.gz ./Zonemaster-LDNS-${version}.tar.gz
+
+RUN cpanm --notest --no-wget \
+    ./Zonemaster-LDNS-${version}.tar.gz
+
+FROM alpine:3.22
+
+# Include only Zonemaster LDNS modules
+COPY --from=build /usr/local/lib/perl5/site_perl/auto/Zonemaster /usr/local/lib/perl5/site_perl/auto/Zonemaster
+COPY --from=build /usr/local/lib/perl5/site_perl/Zonemaster /usr/local/lib/perl5/site_perl/Zonemaster
+
+RUN apk add --no-cache \
+    # Run-time dependencies
+    libidn2 \
+    perl