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/docs/internal/functional-tests/Behavior-TP/behavior02.md

@@ -0,0 +1,39 @@
+## BEHAVIOR02: NODATA returned in response in the event of querying a domain name that exists but no relevant answers in the answer section
+
+### Test case identifier
+
+**BEHAVIOR02:** NODATA returned in response in the event of querying a 
+domain name that exist but no relevant answers in the answer section
+
+### Objective 
+Section 1 of [RFC 2308](https://datatracker.ietf.org/doc/html/rfc2308) mentions that
+"NODATA" is a pseudo RCODE. "NODATA" indicates that there are RRs for the requested
+domain name, but none of them match the record type queried.
+
+"NODATA" is indicated by an answer with RCODE set to "NOERROR" (defined in RFC
+[RFC 1035](https://datatracker.ietf.org/doc/html/rfc1035)) and no relevant answers in the
+answer section.
+
+This test is to verify whether the engine responds with NODATA when
+querying a domain name that exists, but the queried record type does not exist.
+
+### Inputs
+
+The domain to be tested. The domain should be already delegated in the DNS, but
+should not contain delegation RRs or the queried RRs
+
+### Results
+Verifying a domain such as "gouv.fr" which does not have delegation RRs results
+in expected results as you can see from the appendix.
+
+
+### Appendix
+```
+zonemaster-cli gouv.fr
+Seconds Level     Message
+======= ========= =======
+   1.16 CRITICAL  Nameservers for "fr" provided no NS records for tested zone.
+RCODE given was NOERROR.
+   1.16 CRITICAL  Not enough data about gouv.fr was found to be able to run
+tests.
+```