feat(onboarding): remove dead ends for new users (#55)

Registration shows the address used and can start over.
Confirm page says an admin approves; no login link.
Welcome puts next steps first; Steam link returns to the dashboard.
Dashboard and library explain an empty or private library.
First sync shows queued, polls slower up to 10 min, then a calm text.
Login: simple checks, resend offer after 401, password toggles.
Only a real expired link counts as invalid; typed passwords stay.
Default language follows the browser; texts are platform-neutral.

src/components/SteamGameCount.jsx

@@ -43,7 +43,7 @@ const SteamGameCount = ({targetCount}) => {
                 {targetCount > 0
                     ? <Link to="/library" className={`${COUNT_CLASS} hover:text-primary`}>{count}</Link>
                     : <span className={COUNT_CLASS}>{count}</span>}
-                <div className="mt-1 text-sm text-muted-foreground">{t('DASHBOARD.STEAM_GAMES')}</div>
+                <div className="mt-1 text-sm text-muted-foreground">{t('DASHBOARD.GAMES')}</div>
             </div>
             <Link to="/library" className="inline-flex items-center gap-1 text-sm font-medium text-primary hover:underline">
                 {t('DASHBOARD.TO_LIBRARY')} <ArrowRight className="size-4"/>