Flock as list tiles with latest updates

- Each crow is a tile: live avatar, name, latest update, time;
  the most recently updated tile moves to the top
- Red "N waiting" count per tile tracks open questions separately
  from the latest update, so a newer update never hides one
- Phones: no crow strip; two tabs (# todo, Flock) with a count of
  crows waiting on you

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UQnSw4RRWp8uqpj3nsnnXF

ui/index.html

@@ -9,7 +9,12 @@
     <link href="https://fonts.googleapis.com/css2?family=EB+Garamond:ital,wght@0,500;0,700;1,500&family=IM+Fell+English+SC&display=swap" rel="stylesheet" />
   </head>
   <body>
-    <div class="app">
+    <div class="app" id="app" data-view="room">
+      <nav class="tabs" aria-label="Views">
+        <span class="brand">So Many Crows</span>
+        <button class="tab" id="tab-room" type="button" aria-pressed="true"># todo</button>
+        <button class="tab" id="tab-flock" type="button" aria-pressed="false">Flock</button>
+      </nav>
       <aside class="side" aria-label="The flock">
         <div class="brand">So Many Crows</div>
         <h2>The flock</h2>