fix: sync queue insert/append to native Android player

Both 'Als Nächstes einfügen' and 'Am Ende der Queue' updated S.queue in JS
but never called NSBridge, so the native ExoPlayer ignored the change and
kept playing the original next item.

- Export nativeInsertAt(song, position) from player.js
- Call it in showCtxMenu with the exact splice index for insert-next
  and -1 (append) for add-to-end

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

src/ui.js

@@ -3,7 +3,7 @@ import { esc, formatDur, toast } from './utils.js';
 import { api, coverUrl, ndAuth } from './api.js';
 import { THEMES, applyTheme, getCurrentThemeId } from './themes.js';
 // Circular imports — safe (only used inside function bodies)
-import { playQueue, dlSongLocal, toggleStar, togglePlay, renderQueue, syncNpStar, updateStarBtn, npToggleStar, playCurrent, _syncNpDirect, setPlayIcon } from './player.js';
+import { playQueue, dlSongLocal, toggleStar, togglePlay, renderQueue, syncNpStar, updateStarBtn, npToggleStar, playCurrent, _syncNpDirect, setPlayIcon, nativeInsertAt } from './player.js';
 import { navigate, loadPlaylists } from './views.js';
 
 // ─── SIDEBAR ───
@@ -115,11 +115,15 @@ export function showCtxMenu(e, song, list, idx) {
   const items = [
     { icon: '▶', label: 'Abspielen', fn: () => playQueue(list, idx) },
     { icon: '+', label: 'Als Nächstes einfügen', fn: () => {
-        S.queue.splice(S.qIdx+1, 0, {...song});
+        const insertIdx = S.qIdx + 1;
+        S.queue.splice(insertIdx, 0, {...song});
+        nativeInsertAt(song, insertIdx);
         renderQueue(); toast('In Warteschlange eingefügt');
     }},
     { icon: '⬇', label: 'Am Ende der Queue', fn: () => {
-        S.queue.push({...song}); renderQueue(); toast('Zur Queue hinzugefügt');
+        S.queue.push({...song});
+        nativeInsertAt(song, -1);
+        renderQueue(); toast('Zur Queue hinzugefügt');
     }},
     { sep: true },
     { icon: '🎶', label: 'Zu Playlist hinzufügen →', submenu: true, fn: () => openPlModal([song]) },