fix: random albums performance, image cache memory leak, i18n fix (v1.4.1)

- Remove auto-refresh timer from Random Albums (caused 100ms progress
  interval + 30 concurrent fetches every 30s, eventually freezing the app)
- Limit concurrent image fetches to 5 (was unbounded)
- Cap in-memory object URL cache at 150 entries with revokeObjectURL eviction
- Add cancellation flag to useCachedUrl to prevent setState on unmounted components
- Fix hardcoded "Neueste" page title in New Releases (now uses i18n)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/CachedImage.tsx

@@ -10,7 +10,9 @@ export function useCachedUrl(fetchUrl: string, cacheKey: string): string {
   const [resolved, setResolved] = useState('');
   useEffect(() => {
     if (!fetchUrl) { setResolved(''); return; }
-    getCachedUrl(fetchUrl, cacheKey).then(setResolved);
+    let cancelled = false;
+    getCachedUrl(fetchUrl, cacheKey).then(url => { if (!cancelled) setResolved(url); });
+    return () => { cancelled = true; };
   }, [fetchUrl, cacheKey]);
   return resolved || fetchUrl;
 }