Fix #881: discography sort button regression on Artist page (#882)

The early return added in 13cb672 did not account for the reSort flag,
causing the sort button to have no effect when already viewing the
discography tab. Also extend the early-return guard to cover the
groupedReleases case for consistency.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/browsing/artistpage.go

@@ -342,7 +342,7 @@ func (a *ArtistPage) load() {
 }
 
 func (a *ArtistPage) showAlbumGrid(reSort bool) {
-	if a.activeView == 0 && a.albumGrid != nil {
+	if a.activeView == 0 && (a.albumGrid != nil || a.groupedReleases != nil) && !reSort {
 		return // already showing album grid
 	}
 	a.activeView = 0