feat: Add 7 new stacks (Batch 2)

Added stacks:
- nextcloud-aio (Cloud storage)
- wordpress (CMS)
- searxng (Meta search)
- authentik (SSO provider)
- jellyfin (Media server)

All stacks include:
- compose.yml with proper configuration
- README.md with deployment info
- stack.toml for Komodo Resource Sync

stacks/authentik/README.md

@@ -0,0 +1,25 @@
+# Authentik
+
+🔐 SSO / Identity Provider
+
+## Deploy in Komodo
+
+**Pfad:** `stacks/authentik/`
+
+## Ports
+
+- `9000` - HTTP Interface
+- `9443` - HTTPS Interface
+
+## Caddy
+
+```caddyfile
+auth.example.com {
+    reverse_proxy localhost:9000
+}
+```
+
+## Notes
+
+- Komplexes Setup mit PostgreSQL + Redis
+- SECRET_KEY ändern vor erstem Start!