feat(auth): keep remember tokens on session timeout

- add timeout-specific logout path without remember-token revocation

- reset session timers after remember-me auto login

- compact session policy wording in admin settings (DE/EN)

- extend auth tests for timeout/manual logout behavior

lib/Service/Auth/RememberMeService.php

@@ -92,6 +92,9 @@ class RememberMeService
 
         Session::regenerate();
         $this->sessionStore->set('user', $user);
+        $now = time();
+        $this->sessionStore->set('session_started_at', $now);
+        $this->sessionStore->set('session_last_activity', $now);
         if (!empty($user['locale'])) {
             I18n::$locale = (string) $user['locale'];
         }