fix: save plModalSongs before closePlModal clears it

closePlModal() resets S.plModalSongs=[] before ids was computed,
so no songs were ever added to the playlist.

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

src/ui.js

@@ -190,11 +190,12 @@ export function closePlModal() {
   S.plModalSongs = [];
 }
 export async function addSongsToPlaylist(plId, plName) {
+  const songs = [...S.plModalSongs];
   closePlModal();
   try {
-    const ids = S.plModalSongs.map(s => `&songIdToAdd=${s.id}`).join('');
+    const ids = songs.map(s => `&songIdToAdd=${s.id}`).join('');
     await api('updatePlaylist', `&playlistId=${plId}${ids}`);
-    toast(`✅ ${S.plModalSongs.length===1 ? S.plModalSongs[0].title : S.plModalSongs.length+' Songs'} → ${plName}`);
+    toast(`✅ ${songs.length===1 ? songs[0].title : songs.length+' Songs'} → ${plName}`);
   } catch(e) { toast('Fehler: ' + e.message); }
 }
 export async function createAndAddPlaylist() {