fix: inject iTunes previewUrl into Spotify importer track items

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

src/spotify.js

@@ -218,9 +218,25 @@ async function _loadSpotifyTrackArtwork(tracks, listEl) {
         if (match.releaseDate)        t.releaseDate        = match.releaseDate;
         if (match.trackNumber)        t.trackNumber        = match.trackNumber;
         if (match.trackExplicitness)  t.trackExplicitness  = match.trackExplicitness;
+        if (match.previewUrl)         t.previewUrl         = match.previewUrl;
         if (window._spotifyResolved?.tracks?.[idx]) Object.assign(window._spotifyResolved.tracks[idx], t);
         const url = match.artworkUrl100 || match.artworkUrl60 || '';
         if (url) _setArt(artEls[idx], url);
+        if (match.previewUrl) {
+          const item = artEls[idx]?.closest('.gtrack-item');
+          if (item && !item.querySelector('.gtrack-actions .icon-btn.blue')) {
+            const actions = item.querySelector('.gtrack-actions');
+            if (actions) {
+              const btn = document.createElement('button');
+              btn.className = 'icon-btn blue';
+              btn.title = '30s Preview';
+              btn.innerHTML = '<svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor"><polygon points="5 3 19 12 5 21 5 3"/></svg>';
+              btn.onclick = (e) => { e.stopPropagation(); window.playPreview(t); };
+              actions.insertBefore(btn, actions.firstChild);
+              item.onclick = () => window.playPreview(t);
+            }
+          }
+        }
       } catch { /* non-critical */ }
     }));
   }