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/WISHLIST.md

@@ -0,0 +1,11 @@
+# WishList for future version
+
+1.  Multiple points of checking - Should be able to run tests from different end points and get the results and fusion together into one result
+2.  Structured output of the result and/or a library to run the tool
+    from another program (the library may be useful even if the tool has a
+    structured output).
+3.  Developing a Mobile app
+4.  Parallel tests
+5.  It would be nice to test if unknown RR types can be queried (Ref :
+    https://savannah.nongnu.org/bugs/?36909)
+