fix: album download menu not updating in grid views

- Force Map reactivity by re-assigning after .set()
- Add missing downloadStateVersion effect in SearchView
- Ensures download menu updates across all grid views

cp

src/lib/components/views/ArtistDetailView.svelte

@@ -126,6 +126,7 @@
     try {
       const isDownloaded = await checkAlbumFullyDownloaded(albumId);
       albumDownloadStatuses.set(albumId, isDownloaded);
+      albumDownloadStatuses = albumDownloadStatuses;
       return isDownloaded;
     } catch {
       return false;