Home button between back and forward; Alt+Home

The on-screen buttons are now back / home / forward. Home (and Alt+Home)
loads the site on screen from the address it was set up with under Sites &
Page Timing, hidden sites included. A shared buildTabUrl() builds that
address for both the first load and the home button.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZQveYdjfcrEsyazq32

webui/public/index.html

@@ -95,7 +95,7 @@
           <label class="checkbox"><input type="checkbox" name="enablePauseButton"> Pause button</label>
           <label class="checkbox"><input type="checkbox" name="enableKeyboardButton"> On-screen keyboard button</label>
           <label class="checkbox"><input type="checkbox" name="enableNavButton"> Navigation/help button</label>
-          <label class="checkbox"><input type="checkbox" name="enableHistoryButtons"> On-screen back/forward buttons (top middle)</label>
+          <label class="checkbox"><input type="checkbox" name="enableHistoryButtons"> On-screen back / home / forward buttons (top middle)</label>
 
           <fieldset>
             <legend>Home page</legend>
@@ -106,7 +106,7 @@
               </select>
             </label>
             <label>
-              Back/forward button opacity (10 = faint, 100 = solid)
+              Back/home/forward button opacity (10 = faint, 100 = solid)
               <input type="number" name="historyButtonsOpacity" min="10" max="100" step="5">
             </label>
             <label>