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/public/specifications/tests/Nameserver-TP/nameserver08.md

@@ -0,0 +1,44 @@
+## NAMESERVER08: Testing QNAME case insensitivity  
+
+### Test case identifier
+NAMESERVER08 Verify whether the authoritative nameserver response match the 
+case of every letter in the query name
+
+
+### Objective
+The DNS standards require that nameservers treat names with case insensitivity.
+That is, the names example.com and EXAMPLE.COM should resolve to the same IP
+address. However, in the response, most nameservers echo back the name as it
+appeared in the request, preserving the original case.
+
+Therefore, another way to add entropy to requests is to randomly vary the case
+of letters in domain names queried. This technique, also known as "0x20" because
+bit 0x20 is used to set the case of of US-ASCII letters, was first proposed in
+the [IETF internet draft](https://datatracker.ietf.org/doc/html/draft-vixie-dnsext-dns0x20-00) Use of Bit 0x20 in DNS Labels to Improve Transaction
+Identity. With this technique, the nameserver response must match not only the
+query name, but the case of every letter in the name string; for example,
+wWw.eXaMpLe.CoM or WwW.ExamPLe.COm. This may add little or no entropy to queries
+for the top-level and root domains, but it's effective for most hostnames.
+
+### Inputs
+The domain name to be tested.
+
+### Ordered description of steps to be taken to execute the test case
+1. Retrieve all address records for all the name servers using [Method 
+   4](../Methods.md) and [Method 5](../Methods.md).
+2. A random query with mixed case (e.G Www.iETf.Org) is sent to each unique name
+   server IP address found in step 1.
+3. Remember the case of the QNAME in the query sent.
+4. Compare the QNAME in the question section of the response with the string in    step3. 
+5. If the string in step3 and step4 are not equal with respect to case in
+   sensitivity, the test fails.
+
+
+### Outcome(s)
+The test case is Ok only if there are no responses in the authority section 
+
+### Special procedural requirements
+None.
+
+### Intercase dependencies
+None.