The "Sign in with Google" button renders only when /auth/config returns a
google_client_id. Prod's Dokploy env never had GOOGLE_CLIENT_ID set, so the
button was hidden on sapl.ai-automation-hub.tech (visible locally via .env).
Add it to the compose environment block. The client ID is a public identifier
(already exposed to the browser), so it's safe to commit; the client secret is
not needed by the ID-token verification flow and stays out of the repo.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>