feat: track missing tracks in Navidrome playlist creation notification

Collects tracks not matched in Navidrome search during playlist creation
and saves them as 'missing' in the notification — expandable list in the
bell panel labeled 'nicht in Navidrome gefunden'.

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

src/ui.js

@@ -314,6 +314,7 @@ async function _createNdPlaylist(tracks, name) {
   try {
     toast('🎵 Erstelle Navidrome-Playlist…');
     const songIds = [];
+    const missing = [];
     const norm = s => s?.toLowerCase().trim() || '';
     for (const t of tracks) {
       if (!t.trackName) continue;
@@ -325,15 +326,19 @@ async function _createNdPlaylist(tracks, name) {
           norm(s.artist).split(' ')[0] === norm(t.artistName).split(' ')[0]
         ) || songs.find(s => norm(s.title) === norm(t.trackName));
         if (match) songIds.push(match.id);
-      } catch {}
+        else missing.push(t.trackName);
+      } catch { missing.push(t.trackName); }
     }
     if (!songIds.length) {
       toast('⚠ Keine Tracks in Navidrome gefunden — zuerst Library scannen, dann Playlist manuell anlegen');
+      _addNotif({ id: 'pl_' + Date.now(), title: `Playlist: ${name}`, artist: '', status: 'error', message: 'Keine Tracks in Navidrome gefunden — Library scan nötig', missing, timestamp: Date.now(), read: false });
       return;
     }
     const songParams = songIds.map(id => `&songId=${encodeURIComponent(id)}`).join('');
     await api('createPlaylist', `&name=${encodeURIComponent(name)}${songParams}`);
+    const msg = `${songIds.length}/${tracks.length} Tracks hinzugefügt${missing.length ? `, ${missing.length} nicht gefunden` : ''}`;
     toast(`✅ Playlist "${name}" mit ${songIds.length}/${tracks.length} Tracks erstellt`);
+    _addNotif({ id: 'pl_' + Date.now(), title: `Playlist: ${name}`, artist: '', status: 'done', message: msg, missing, timestamp: Date.now(), read: false });
   } catch(e) {
     toast('Playlist-Erstellung fehlgeschlagen: ' + e.message);
   }
@@ -408,6 +413,9 @@ function _renderNotifList() {
     const failedHtml = n.failed?.length
       ? `<details class="notif-failed"><summary>${n.failed.length} Track${n.failed.length > 1 ? 's' : ''} fehlgeschlagen</summary><ul>${n.failed.map(f => `<li>${esc(f)}</li>`).join('')}</ul></details>`
       : '';
+    const missingHtml = n.missing?.length
+      ? `<details class="notif-failed"><summary>${n.missing.length} Track${n.missing.length > 1 ? 's' : ''} nicht in Navidrome gefunden</summary><ul>${n.missing.map(f => `<li>${esc(f)}</li>`).join('')}</ul></details>`
+      : '';
     return `<div class="notif-card${n.read ? '' : ' unread'}">
       <div class="notif-card-top">
         <span class="notif-icon">${icon}</span>
@@ -419,6 +427,7 @@ function _renderNotifList() {
       </div>
       ${n.message ? `<div class="notif-msg">${esc(n.message)}</div>` : ''}
       ${failedHtml}
+      ${missingHtml}
     </div>`;
   }).join('');
 }