feat: Astro Starlight Docs-Site für BTC MAIN AI Application Layer

Vollständige Dokumentations-Site mit:
- Einstieg: Einführung, Schnellstart, Kernkonzepte
- Guides: Deployment, CI/CD, Env-Vars, Domains, Logs
- API-Referenz: Überblick, Auth, Applications, Deployments
- Referenz: Tech Stack, FAQ
- Dockerfile + nginx für containerisiertes Deployment

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

astro.config.mjs

@@ -0,0 +1,66 @@
+import { defineConfig } from 'astro/config';
+import starlight from '@astrojs/starlight';
+
+export default defineConfig({
+  integrations: [
+    starlight({
+      title: 'BTC MAIN · Managed AI Now',
+      description: 'Dokumentation des AI Application Layer — Deployment, Betrieb und API-Referenz',
+      defaultLocale: 'de',
+      logo: {
+        src: './src/assets/logo.svg',
+        replacesTitle: false,
+      },
+      social: [
+        { icon: 'external', label: 'BTC AG', href: 'https://www.btc-ag.com' },
+      ],
+      editLink: {
+        baseUrl: 'https://git.coolai.btc-ag.cloud/thsoring/docs/edit/main/',
+      },
+      sidebar: [
+        {
+          label: 'Einstieg',
+          items: [
+            { label: 'Einführung', slug: 'einstieg/einfuehrung' },
+            { label: 'Schnellstart', slug: 'einstieg/schnellstart' },
+            { label: 'Kernkonzepte', slug: 'einstieg/konzepte' },
+          ],
+        },
+        {
+          label: 'Anleitungen',
+          items: [
+            { label: 'App deployen', slug: 'guides/app-deployen' },
+            { label: 'CI/CD Pipelines', slug: 'guides/cicd-pipelines' },
+            { label: 'Umgebungsvariablen', slug: 'guides/umgebungsvariablen' },
+            { label: 'Custom Domains', slug: 'guides/custom-domains' },
+            { label: 'Logs & Monitoring', slug: 'guides/logs-monitoring' },
+          ],
+        },
+        {
+          label: 'API-Referenz',
+          items: [
+            { label: 'Überblick', slug: 'api/uebersicht' },
+            { label: 'Authentifizierung', slug: 'api/authentifizierung' },
+            { label: 'Applications', slug: 'api/applications' },
+            { label: 'Deployments', slug: 'api/deployments' },
+          ],
+        },
+        {
+          label: 'Referenz',
+          items: [
+            { label: 'Tech Stack', slug: 'referenz/tech-stack' },
+            { label: 'FAQ', slug: 'referenz/faq' },
+          ],
+        },
+      ],
+      customCss: ['./src/styles/custom.css'],
+      head: [
+        {
+          tag: 'meta',
+          attrs: { property: 'og:image', content: '/og-image.png' },
+        },
+      ],
+      components: {},
+    }),
+  ],
+});