Add i18n, branding, user management, health checks, and cleanup for deployment

- Multi-language support (EN/DE) with i18n engine and language files
- Configurable branding (name, subtitle, logo) in Settings
- Global default language and per-user language preference
- User management router with CRUD endpoints
- Customer status sync on start/stop/restart
- Health check fixes: derive status from container state, remove broken wget healthcheck
- Caddy reverse proxy and dashboard env templates for customer stacks
- Updated README with real hardware specs, prerequisites, and new features
- Removed .claude settings (JWT tokens) and build artifacts from tracking
- Updated .gitignore for .claude/ and Windows artifacts

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

app/routers/monitoring.py

@@ -71,6 +71,7 @@ async def all_customers_status(
             entry["deployment_status"] = c.deployment.deployment_status
             entry["containers"] = containers
             entry["relay_udp_port"] = c.deployment.relay_udp_port
+            entry["dashboard_port"] = c.deployment.dashboard_port
             entry["setup_url"] = c.deployment.setup_url
         else:
             entry["deployment_status"] = None