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/test-zone-data/set-ip.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+
+set -u
+
+# This script will read address-plan.md and extract registered IPv4 addresses.
+# From the extracted IPv4 address the matching IPv6 address is created.
+#
+# Since loopback (lo) is already configured with 127.0.0.0/8 there is no need
+# to the configure the loopback interface with the IPv4 addresses for the test
+# zones (all are within 127.0.0.0/8).
+#
+# The IPv6 addresses are configured on the loopback interface (lo) with this
+# script. If the address is already configured, an error message is outputted by
+# ip(), but can be ignored.
+
+
+usage() { echo "Usage: sudo $0" 1>&2;
+          echo 1>&2;
+          exit 1; }
+
+while getopts "h" o; do
+    case "${o}" in
+        h)
+            usage
+            ;;
+        *)
+            usage
+            ;;
+    esac
+done
+shift $((OPTIND-1))
+
+# Make sure the script is run by  root
+if [ $(id -u) -ne 0 ] ; then
+    echo "You must be root." 1>&2
+    echo "Run 'sudo $0'" 1>&2
+    exit 1
+fi
+
+# Get path of this script
+path=$(dirname $0)
+
+
+# address-plan.md must be in the same folder as this script
+datafile="$path/address-plan.md"
+
+
+# Function to add IPv4 address
+add_ipv4_address() {
+  local ip=$1
+  cmd="ip addr add $ip/32 dev lo"
+  echo -n "Adding $ip : "
+  $cmd && echo "added"
+}
+
+
+# Function to add IPv6 address
+add_ipv6_address() {
+  local ip=$1
+  local ipv6=$(echo $ip | sed 's/\./:/g') # Convert colon to dot
+    cmd="ip addr add fda1:b2:c3::$ipv6/128 dev lo"
+    echo -n "Adding fda1:b2:c3::$ipv6 : "
+    $cmd && echo "added"
+}
+
+
+# Read every line in the data file (markdown)
+while IFS= read -r line; do
+  # Get IP addresses without prefix (e.g. /24)
+  if [[ $line =~ ^\|\ ([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)\ +\| ]]; then
+      ip_address=${BASH_REMATCH[1]}
+      # Add address for IPv4
+      add_ipv4_address $ip_address
+      # Add address for IPv6
+      add_ipv6_address $ip_address
+  fi
+done < $datafile
+
+
+# An alternative approach is to run the following two commands to make all IPv6
+# addresses in the /64 range be available.
+#
+# $ sudo ip -6 route add to local fda1:b2:c3::/64 dev lo
+# $ sudo sysctl -w net.ipv6.ip_nonlocal_bind=1
+#
+# Migration to that approach should be combined with an update of the  address
+# plan file (address-plan.md) and probably combined with specific address plans
+# with each test case.