Add features: escalating turn reminder, AFK AI takeover, public rooms, persistent rejoin

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/index.html

@@ -51,15 +51,29 @@
           <button class="score-btn" data-score="200">200</button>
         </div>
       </div>
+      <div class="field">
+        <label>Visibility</label>
+        <div class="visibility-toggle">
+          <button class="visibility-btn active" data-public="false">🔒 Private</button>
+          <button class="visibility-btn" data-public="true">🌐 Public</button>
+        </div>
+      </div>
       <button id="btn-create" class="btn-primary">Create Game</button>
     </div>
 
     <div id="tab-join" class="tab-panel">
+      <div class="public-rooms-section">
+        <div class="rooms-header">
+          <span>Public Rooms</span>
+          <button id="btn-refresh-rooms" class="btn-refresh">↺ Refresh</button>
+        </div>
+        <div id="public-rooms-list"><p class="hint">Switch to this tab to load rooms.</p></div>
+      </div>
       <div class="field">
-        <label>Room Code</label>
+        <label>Or enter a Room Code</label>
         <input id="input-code" type="text" maxlength="8" placeholder="e.g. AB12CD" autocomplete="off" style="text-transform:uppercase">
       </div>
-      <button id="btn-join" class="btn-primary">Join Game</button>
+      <button id="btn-join" class="btn-primary">Join by Code</button>
       <hr style="border-color:rgba(255,255,255,.1);margin:4px 0">
       <div class="field">
         <label>Watch as spectator</label>
@@ -77,6 +91,7 @@
   <div class="waiting-box">
     <button id="btn-leave-waiting" class="btn-leave-screen">← Leave</button>
     <h2>Waiting for Players</h2>
+    <div id="waiting-public-badge" class="waiting-public-badge">🔒 Private</div>
     <div class="room-code-box">
       <span class="label">Room Code</span>
       <span id="display-room-code" class="room-code">——</span>
@@ -126,6 +141,18 @@
   <!-- Spectator banner -->
   <div id="spectator-banner" class="spectator-banner hidden">👁 Spectating — watching only</div>
 
+  <!-- AFK warning banner -->
+  <div id="afk-banner" class="afk-banner hidden">
+    <span id="afk-banner-msg"></span>
+    <button id="afk-vote-btn">Let AI Play</button>
+    <button id="afk-dismiss-btn">Dismiss</button>
+  </div>
+
+  <!-- AI control banner -->
+  <div id="ai-control-banner" class="ai-control-banner hidden">
+    <span id="ai-control-msg"></span>
+  </div>
+
   <!-- Table grid -->
   <div id="table-grid">