Only the table host splits the pot; host buttons beside the table name

- Showdown winners can now be chosen only by the table host (others see
  "ホストが勝者を選んでいます"); if the host leaves, the next host does it
- START / pause moved into the header to the right of the table name
  (pause is an icon button), freeing the row they used to occupy

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/table.html

@@ -16,15 +16,14 @@
     <div class="table-header">
       <button class="icon-btn leave" id="leave" aria-label="退席する" title="退席する">⏏</button>
       <h1 id="table-name"></h1>
+      <!-- ホストだけに表示 -->
+      <span class="host-controls" id="host-controls" hidden>
+        <button class="btn btn-green btn-sm" id="start">START</button>
+        <button class="icon-btn" id="pause" aria-label="一時停止" title="一時停止">⏸</button>
+      </span>
       <button class="icon-btn" id="share" aria-label="サイトのリンクをコピー" title="サイトのリンクをコピー">🔗</button>
     </div>
 
-    <div class="host-controls" id="host-controls" hidden>
-      <button class="btn btn-green" id="start">START ▶</button>
-      <button class="btn btn-dark" id="pause">一時停止</button>
-    </div>
-    <div class="host-spacer" id="host-spacer"></div>
-
     <div class="level-bar">
       <span class="lv" id="level"></span>
       <span class="blinds" id="blinds"></span>