feat: production-ready TLS with self-signed cert init container

Standard OIDC architecture: subdomain routing (auth.HOST, server.HOST),
TLS via Traefik, self-signed cert auto-generated on first boot.

- Add traefik-certs init container (generates wildcard self-signed cert)
- Enable TLS on all Traefik routers (websecure entrypoint)
- HTTP→HTTPS redirect in traefik.yml
- Host-based routing for all services (no more path conflicts)
- PUBLIC_PROTOCOL env var (https default, configurable)
- Protocol-aware redirect URIs in bootstrap
- Protocol-aware UI fallbacks

Customer bootstrap: set PUBLIC_HOST + DNS records + docker compose up.
For production TLS, configure Traefik ACME (Let's Encrypt).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/Layout.tsx

@@ -162,7 +162,7 @@ export function Layout() {
         <Sidebar.FooterLink
           icon={<ObsIcon />}
           label="View Dashboard"
-          onClick={() => window.open(`http://server.${window.location.hostname}`, '_blank', 'noopener')}
+          onClick={() => window.open(`${window.location.protocol}//server.${window.location.hostname}`, '_blank', 'noopener')}
         />
 
         {/* User info + logout */}