feat(playlists): Add playlist management - filter, sort, view modes, collage artwork

- Add PlaylistCollage component with Qobuz-style overlapping covers
- Add playlist_settings columns (hidden, position) with migration
- Add playlist_stats table for play count tracking
- Add backend commands for playlist management:
  - playlist_get_all_settings, playlist_set_hidden
  - playlist_set_position, playlist_reorder
  - playlist_get_stats, playlist_get_all_stats
  - playlist_increment_play_count
- Update Sidebar with filter dropdown (All/Visible/Hidden)
- Add sort dropdown (Name/Recent/Custom)
- Add view toggle between list and grid modes
- Fix TypeScript errors in +page.svelte and TitleBar.svelte

src/routes/+page.svelte

@@ -1417,16 +1417,16 @@
         onToggleLyrics={toggleLyricsSidebar}
         lyricsActive={lyricsSidebarVisible}
         onArtistClick={() => {
-          if (currentTrack.isLocal) {
+          if (currentTrack?.isLocal) {
             showToast('Local track - search for artist in Search', 'info');
-          } else if (currentTrack.artistId) {
+          } else if (currentTrack?.artistId) {
             handleArtistClick(currentTrack.artistId);
           }
         }}
         onAlbumClick={() => {
-          if (currentTrack.isLocal) {
+          if (currentTrack?.isLocal) {
             navigateTo('library');
-          } else if (currentTrack.albumId) {
+          } else if (currentTrack?.albumId) {
             handleAlbumClick(currentTrack.albumId);
           }
         }}