fix: bump SW cache to v39, split multi-artists by ' / ', name-search fallback for artist nav

- sw.js: ns-v38 → ns-v39 forces PWA cache clear so previous fixes take effect
- components: split s.artist by ' / ' in makeSongItem — each part becomes its
  own clickable link; noArtistLink turns all parts into plain text
- views: s_goArtist searches Navidrome by name when no artistId is available
  (needed for secondary artists that only have the primary artistId in the song)

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

src/views.js

@@ -840,9 +840,16 @@ export async function searchAndPreview(trackName, artistName) {
   } catch { toast('Suche fehlgeschlagen'); }
 }
 
-export function s_goArtist(e, name, id) {
+export async function s_goArtist(e, name, id) {
   if(!name) return;
-  navigate('artist-detail', {id: id||name, name});
+  if(id) { navigate('artist-detail', {id, name}); return; }
+  try {
+    const r = await api('search3', `&query=${encodeURIComponent(name)}&artistCount=5&albumCount=0&songCount=0`);
+    const artists = r.searchResult3?.artist || [];
+    const match = artists.find(a => a.name.toLowerCase() === name.toLowerCase()) || artists[0];
+    if(match) navigate('artist-detail', {id: match.id, name: match.name});
+    else toast('Künstler nicht gefunden');
+  } catch { toast('Suche fehlgeschlagen'); }
 }
 
 export function s_goAlbum(e, albumId, albumName, artist, artistId) {