refactor: restyle web UI wordmark as SONG / TRACE

src/songtrace/static/index.html

@@ -4,7 +4,7 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <meta name="color-scheme" content="dark">
-<title>karaoke-maker</title>
+<title>songtrace</title>
 <style>
 @font-face {
   font-family: "Chakra Petch";
@@ -473,7 +473,7 @@ button { cursor: pointer; }
 
 <aside id="sidebar">
   <div class="brand">
-    <h1 class="wordmark"><span>KARAOKE</span> <span class="second">MAKER</span></h1>
+    <h1 class="wordmark"><span>SONG</span> <span class="second">TRACE</span></h1>
     <div class="kana" aria-hidden="true">カラオケ</div>
   </div>
   <div>