auth: sessões mais longas com silent renew automático

Adiciona offline_access ao scope e automaticSilentRenew para renovar
tokens silenciosamente sem forçar re-login. Requer Access Token validity
aumentado no provider Authentik (de 5min para 8h).

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

src/auth/config.ts

@@ -5,8 +5,9 @@ export const oidcConfig = {
   client_id: 'OKRSM2FZeSxJDhoV9e17dGRU1L1NEE1JBdnPVWTO',
   redirect_uri: window.location.origin + '/callback',
   post_logout_redirect_uri: window.location.origin,
-  scope: 'openid profile email',
+  scope: 'openid profile email offline_access',
   userStore: new WebStorageStateStore({ store: window.localStorage }),
+  automaticSilentRenew: true,
   onSigninCallback: () => {
     window.history.replaceState({}, document.title, window.location.pathname);
   },