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/SteamGameCount.jsx

@@ -4,15 +4,21 @@ import {useTranslation} from 'react-i18next';
 import {ArrowRight, Gamepad2} from 'lucide-react';
 
 import {Card} from '@/components/ui/card';
+import useReducedMotion from '../hooks/useReducedMotion.js';
 
 const DURATION_MS = 1000;
 const COUNT_CLASS = 'block text-5xl font-bold tracking-tight tabular-nums';
 
 const SteamGameCount = ({targetCount}) => {
     const {t} = useTranslation();
+    const reduce = useReducedMotion();
     const [count, setCount] = useState(0);
 
     useEffect(() => {
+        if (reduce) {
+            setCount(targetCount);
+            return undefined;
+        }
         let frame;
         let startTime;
         const animate = (timestamp) => {
@@ -25,7 +31,7 @@ const SteamGameCount = ({targetCount}) => {
         };
         frame = requestAnimationFrame(animate);
         return () => cancelAnimationFrame(frame);
-    }, [targetCount]);
+    }, [targetCount, reduce]);
 
     return (
         <Card className="relative justify-between overflow-hidden p-6">