feat(welcome): add welcome page for new users after first login

Shows six feature cards and two next steps (Steam, import). The dashboard
redirects to it while Auth settings.welcomeSeenAt is null; "Let's go" and
"Skip" set the stamp. Settings links to it to reopen later.

src/components/AccountInfoCard.jsx

@@ -1,6 +1,8 @@
+import {Link} from 'react-router-dom';
 import {useTranslation} from 'react-i18next';
-import {UserRound} from 'lucide-react';
+import {Rocket, UserRound} from 'lucide-react';
 
+import {Button} from '@/components/ui/button';
 import {Card, CardContent, CardHeader, CardTitle} from '@/components/ui/card';
 import {useCurrentUserContext} from '../context/CurrentUserContext.jsx';
 import {formatDateTime} from '../utils/format.js';
@@ -38,6 +40,9 @@ export default function AccountInfoCard() {
                         </div>
                     ))}
                 </dl>
+                <Button asChild variant="link" className="mt-3 h-auto p-0">
+                    <Link to="/welcome"><Rocket/>{t('SETTINGS.OPEN_WELCOME')}</Link>
+                </Button>
             </CardContent>
         </Card>
     );