Add web UI with Smokey's crow as the stand-in mascot

- ui/: Vite + plain TypeScript, builds into ./web for `crows serve`
- CrowView mirrors CrowModel in RIVE_CONTRACT.md (pose, trust,
  reactions) so the .riv can replace the SVG later
- Event handling follows the contract's mapping table; server text
  is only ever inserted as text
- Prank: toast plus a send-button cooldown countdown
- art/crow.svg: source art for Rive import

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

ui/index.html

@@ -0,0 +1,34 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>So Many Crows</title>
+    <link rel="preconnect" href="https://fonts.googleapis.com" />
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+    <link href="https://fonts.googleapis.com/css2?family=Nunito:wght@600;800;900&display=swap" rel="stylesheet" />
+  </head>
+  <body>
+    <header class="top">
+      <h1>So Many Crows</h1>
+      <label class="who">You are <input id="requester" maxlength="40" autocomplete="off" /></label>
+    </header>
+
+    <main>
+      <section class="perch" id="perch" aria-label="The flock"></section>
+      <p class="banner" id="banner" role="status" hidden></p>
+
+      <form class="composer" id="composer">
+        <label for="list">Your todo list, one item per line</label>
+        <textarea id="list" rows="5" placeholder="- [ ] What is the difference between a crow and a raven&#10;- [ ] Draft a tagline for So Many Crows"></textarea>
+        <button class="btn btn-go" id="send" type="submit">Send the flock</button>
+      </form>
+
+      <ol class="cards" id="cards" aria-live="polite"></ol>
+      <p class="meter" id="meter" hidden></p>
+    </main>
+
+    <div class="toast" id="toast" role="alert" hidden></div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>