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>

web/index.html

@@ -6,16 +6,21 @@
 <meta name="theme-color" content="#0d0e12">
 <title>Stemify</title>
 <link rel="stylesheet" href="style.css">
+<style id="theme"></style>
+<style id="custom-css"></style>
 </head>
 <body>
 <div id="app">
   <aside id="nav">
     <div class="brand">stemify</div>
+    <form id="search"><input type="search" name="q" placeholder="Search" autocomplete="off"></form>
     <a href="#/albums" data-nav="albums">Albums</a>
     <a href="#/artists" data-nav="artists">Artists</a>
+    <a href="#/songs" data-nav="songs">Songs</a>
+    <a href="#/genres" data-nav="genres">Genres</a>
     <a href="#/playlists" data-nav="playlists">Playlists</a>
-    <a href="#/stems" data-nav="stems">Stems only</a>
-    <form id="search"><input type="search" name="q" placeholder="Search" autocomplete="off"></form>
+    <a href="#/downloads" data-nav="downloads">Downloads</a>
+    <div id="live" hidden></div>
     <a href="#/settings" data-nav="settings" class="settings-link">Settings</a>
   </aside>
   <main id="view"></main>
@@ -41,8 +46,9 @@
     </div>
   </div>
   <div class="right">
-    <select id="speed" title="Speed"></select>
+    <select id="speed" title="Speed ([ and ])"></select>
     <button id="b-mixer" class="pill" title="Mixer (M)"></button>
+    <button id="b-lyrics" class="pill" title="Lyrics (L)"></button>
     <button id="b-queue" class="pill" title="Queue (Q)"></button>
     <input id="volume" type="range" min="0" max="1" step="0.01" title="Volume">
   </div>