Web player overhaul; iOS random sort, stems-only filter, pooled libraries

Web: live Stem Now status that tracks every queued song (albums too),
right-click menus with Stem Now, Songs and Genres pages, a Stems Only
filter in place of the sidebar section, Random sort, several pooled
Plex servers and libraries, themes plus custom CSS, a reorganised
settings page that loads without a refresh, saved mixes, karaoke and
synced lyrics, stem playlists and offline downloads.

iOS: Random in every sort menu, a Stems Only toggle (sort menu and
Settings), and several music libraries pooled from the signed-in server.
Settings now persists karaoke and speed across launches.

stemd writes a status file that stemserve serves at /api/queue.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/Stemify/UI/Screens/PlaylistScreens.swift

@@ -47,8 +47,10 @@ struct PlaylistsScreen: View {
                 Button { kind == .Plex ? newPlaylist() : newStemPlaylist() } label: { Image(systemName: "plus") }
             }
         }
-        .task(id: "\(g.settings.musicSection)|\(sort.param)|\(reload)") {
-            await LoadState.load($lists) { try await g.plex.playlists(sort: sort.param) }
+        .task(id: "\(g.settings.musicSection)|\(sort.token)|\(reload)") {
+            // /playlists may not take sort=random, so Random shuffles here.
+            let random = sort.option.random
+            await LoadState.load($lists) { try await random ? g.plex.playlists().shuffled() : g.plex.playlists(sort: sort.param) }
         }
     }