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-backend/docs/Architecture.md

@@ -0,0 +1,99 @@
+# Architecture
+
+The Zonemaster *Backend* is a system for performing domain health checks and
+keeping records of performed domain health checks.
+
+A Zonemaster *Backend* system consists of at least three components: a
+single *Database*, a single *Test Agent* and one or more *RPC API daemons*.
+
+
+## Components
+
+### Database
+
+The *Database* stores health check requests and results. The *Backend*
+architecture is oriented around a single central *Database*.
+
+All times in the database are stored in UTC.
+
+
+### Test Agent
+
+A Zonemaster *Test Agent* is a daemon that picks up *test* requests from the
+*Database*, runs them using the *Zonemaster Engine* library, and records the results back
+to the *Database*. A single *Test Agent* may handle several requests concurrently.
+The *Backend* architecture supports a single *Test Agent* daemon interacting with a single *Database*.
+
+>
+> TODO: List all files these processes read and write.
+>
+> TODO: List everything these processes open network connections to.
+>
+> TODO: Describe in which order *test* are processed.
+>
+> TODO: Describe how concurrency, parallelism and synchronization works within a single *Test Agent*.
+>
+> TODO: Describe how synchronization works among parallel *Test Agents*.
+>
+
+
+### Web backend
+
+A Zonemaster *Web backend* is a daemon providing a JSON-RPC interface for
+recording *test* requests in the *Database* and fetching *test* results from the
+*Database*. The *Backend* architecture supports multiple *RPC API daemons*
+interacting with the same *Database*.
+
+This only needs to be run as root in order to make sure the log file
+can be opened. The `starman` process will change to the `www-data` user as
+soon as it can, and all of the real work will be done as that user.
+
+>
+> TODO: List all ports these processes listen to.
+>
+> TODO: List all files these processes read and write.
+>
+> TODO: List everything these processes open network connections to.
+>
+
+
+## Glossary
+
+### Test
+
+### Batch
+
+### Test result
+
+### Test module
+
+### Message
+
+### Profile
+
+A profile is a configuration for Zonemaster Engine; see the [profiles
+overview] for context.
+Zonemaster Backend allows administrators to [configure the set of
+available profiles].
+
+Each available profile has a [profile name].
+A profile named `default` is always available.
+Each available profile is based on the [Zonemaster Engine default profile].
+Each one (with the possible exception of `default`) has a [profile file]
+with profile data overriding the Zonemaster Engine default profile.
+
+The [RPC-API] contains several methods that accept profile name arguments.
+
+
+### Engine
+
+The Zonemaster *Engine* is a library for performing *tests*. It's hosted in [its
+own repository](https://github.com/zonemaster/zonemaster-engine/).
+
+--------
+[Configure the set of available profiles]: https://github.com/zonemaster/zonemaster/blob/develop/docs/public/configuration/backend.md#profiles-section
+[Profile file]: https://metacpan.org/pod/Zonemaster::Engine::Config#PROFILE-DATA
+[Profile name]: https://github.com/zonemaster/zonemaster/blob/master/docs/public/using/backend/rpcapi-reference.md#profile-name
+[Profiles overview]: https://github.com/zonemaster/zonemaster/blob/master/docs/internal/design/Profiles.md
+[RPC-API]: https://github.com/zonemaster/zonemaster/blob/master/docs/public/using/backend/rpcapi-reference.md
+[Zonemaster Engine default profile]: https://metacpan.org/pod/Zonemaster::Engine::Config#DESCRIPTION