style: adopt mewlody workspace shell

src/App.svelte

@@ -22,18 +22,18 @@
 
 <div class="app-shell">
   <header class="app-bar">
-    <div class="brand"><span class="brand-mark">T</span><span>TRIXIE</span></div>
-    <nav class="top-nav" aria-label="Primary navigation">
-      {#each ['Live dashboard', 'Chat', 'Bot', 'Overlays'] as item}
-        <button class:active={activeView === item} class="nav-item" onclick={() => (activeView = item)}>{item}</button>
-      {/each}
-    </nav>
+    <div class="brand"><span class="brand-mark">◇</span><span>TRIXIE</span></div>
     <div class="app-actions"><span class:online={connectionState === 'CONNECTED'} class="connection-state">{connectionState}</span><button class="icon-button" aria-label="Settings">⚙</button></div>
   </header>
 
   <main class="workspace">
     <aside class="side-panel">
       <div class="panel-header"><span>TRIXIE</span><span class="panel-kicker">CONTROL</span></div>
+      <nav class="side-nav" aria-label="Primary navigation">
+        {#each ['Live dashboard', 'Chat', 'Bot', 'Overlays'] as item}
+          <button class:active={activeView === item} class="side-nav-item" onclick={() => (activeView = item)}>{item}</button>
+        {/each}
+      </nav>
       <div class="server-card">
         <div class="micro">SERVER CONNECTION</div>
         <div class="server-status"><span class:good={connectionState === 'CONNECTED'} class="status-dot"></span>{connectionState}</div>