feat: replace native confirm() with custom styled dialog

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

src/main.js

@@ -28,7 +28,7 @@ import {
   createPlaylistPrompt, showSongInfo, closeInfoModal, openDlModal, closeDlModal,
   selectDlType, executeDownload, executeSpotifyDownload, openEditPlModal, closeEditPlModal,
   saveEditPlaylist, editPlUploadCover, editPlCoverSelected, editPlRemoveCover,
-  deletePlaylist,
+  deletePlaylist, _confirmOk, _confirmCancel,
   toggleMobileSearch, closeMobileSearch, switchSetupTab,
   toggleNotifPanel, deleteNotif, clearNotifs, initNotifBell,
 } from './ui.js';
@@ -236,7 +236,7 @@ Object.assign(window, {
   showSongInfo, closeInfoModal,
   openDlModal, closeDlModal, selectDlType, executeDownload,
   openEditPlModal, closeEditPlModal, saveEditPlaylist,
-  editPlUploadCover, editPlCoverSelected, editPlRemoveCover, deletePlaylist,
+  editPlUploadCover, editPlCoverSelected, editPlRemoveCover, deletePlaylist, _confirmOk, _confirmCancel,
   toggleMobileSearch, closeMobileSearch, switchSetupTab,
   toggleNotifPanel, deleteNotif, clearNotifs,
   // App

src/ui.js

@@ -572,10 +572,23 @@ export async function editPlRemoveCover() {
   } catch(e) { S._ndToken = null; toast('Fehler: '+e.message); }
 }
 
+let _confirmResolve = null;
+export function _confirmOk()     { document.getElementById('confirm-overlay').classList.remove('open'); _confirmResolve?.(true);  _confirmResolve = null; }
+export function _confirmCancel() { document.getElementById('confirm-overlay').classList.remove('open'); _confirmResolve?.(false); _confirmResolve = null; }
+
+function showConfirm(title, msg, okLabel = 'Bestätigen') {
+  document.getElementById('confirm-title').textContent = title;
+  document.getElementById('confirm-msg').textContent   = msg;
+  document.getElementById('confirm-ok-btn').textContent = okLabel;
+  document.getElementById('confirm-overlay').classList.add('open');
+  return new Promise(resolve => { _confirmResolve = resolve; });
+}
+
 export async function deletePlaylist() {
   const pl = S._currentPlaylist;
   if (!pl) return;
-  if (!confirm(`Playlist "${pl.name}" wirklich löschen?`)) return;
+  const ok = await showConfirm('Playlist löschen', `"${pl.name}" wird unwiderruflich gelöscht.`, 'Löschen');
+  if (!ok) return;
   try {
     await api('deletePlaylist', `&id=${pl.id}`);
     closeEditPlModal();