Add Authorization Code + PKCE login/logout against Zitadel, handled entirely
server-side with an httpOnly signed session cookie:
- $lib/server/auth: openid-client discovery (config cached), jose-signed
session encode/decode, cookie/name constants
- routes: /login (builds the authorize URL with PKCE/state/nonce, ?mode=register
-> prompt=create), /auth/callback (code exchange + session cookie),
/logout (clears session + Zitadel end_session)
- hooks.server populates locals.user/accessToken from the session
- +layout.server exposes the user; Navbar shows the signed-in user + Salir,
or Iniciar sesión / Registrarse
- switch to adapter-node; env-driven config (.env gitignored, .env.example
committed) with issuer http://host.docker.internal:8080
Verified: svelte-check + build clean; dev smoke test shows the landing in the
logged-out state and /login issuing a 302 to Zitadel's authorize endpoint with
PKCE/state/nonce (discovery reachable). Real client id/secret still needed to
complete the token exchange.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>