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-gui/e2e/global-setup.ts

@@ -0,0 +1,19 @@
+import { test as base } from '@playwright/test';
+import { setupApiMocks } from './utils/app.utils';
+
+/**
+ * Global test setup that runs before each test
+ * - Sets up API mocking to avoid needing a real backend
+ * - Waits for network to be idle before proceeding
+ */
+export const test = base.extend({
+    page: async ({ page }, use) => {
+        // Setup API mocks for all tests
+        await setupApiMocks(page);
+
+        // Use the page in the test
+        await use(page);
+    },
+});
+
+export { expect } from '@playwright/test';