fix(ux): apply UX quick wins (#54)

Get started links to registration and says an admin approves accounts.
Back navigation restores the library scroll; search no longer fills history.
Steam and PSN unlink ask first. Any close marks news as seen.
Confetti plays only when the level rises on the page.
Count-ups respect reduced motion. Html lang follows the UI language.
Add a 404 page, translated role and dialog close label.

src/components/AccountInfoCard.jsx

@@ -21,7 +21,7 @@ export default function AccountInfoCard() {
     const {user: profile} = useCurrentUserContext();
     const accountRows = [
         [t('SETTINGS.EMAIL'), profile?.email],
-        [t('SETTINGS.ROLE'), profile?.role],
+        [t('SETTINGS.ROLE'), profile?.role && t(`ROLES.${profile.role}`)],
         [t('SETTINGS.CREATED_DATE'), formatDate(profile?.createdDate, i18n.language)],
         [t('SETTINGS.LAST_LOGIN'), formatDate(profile?.lastLogin, i18n.language)],
     ];