Fix Keycloak logout confirmation and stale logged-in avatar after token refresh fails

[UdayRajSahai2]

Summary

1. Hitting Log Out with no usable session was sending users to Keycloak /logout without a valid id_token_hint, which showed the “Do you want to log out?” page. Logout now goes to Keycloak only when a session, id_token, and successful refresh exist; otherwise it goes to /login, which already calls signIn('keycloak').So it was suggested don't show logout page instead redirect to login
   Issue : This logout page does not make sense as we are not giving any option other than logging out

On Logout:
Still logged in: tell Keycloak to log out in the background, then go to login. Do not show the logout page.
Already expired: skip Keycloak. Go straight to login.
Users should never see the Keycloak logout page.

2.After RefreshAccessTokenError, NextAuth still kept session.user, so the homepage avatar sometimes looked logged in. SessionGuard now signOuts to clear that dead session. Dashboard still redirects to Keycloak login, same as before.