fix splitting layout bug - was not splitting visually original shell

internals/web/shell.html

@@ -148,6 +148,14 @@
             </svg>
             End
         </button>
+        <!-- Logout (sign out, workspace preserved) -->
+        <button class="tb-btn tb-logout" onclick="doLogout()" title="Sign out — workspace is preserved, sign in again to resume">
+            <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                <rect x="3" y="11" width="18" height="11" rx="2"/>
+                <path d="M7 11V7a5 5 0 0 1 10 0v4"/>
+            </svg>
+            Logout
+        </button>
         <!-- Upload -->
         <button class="tb-btn" onclick="openModal('upOverlay')" title="Upload file">
             <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
@@ -216,10 +224,17 @@
             <table class="info-table">
                 <tr><td>Link button</td><td>Copy shareable workspace URL — open on any device to resume all tabs &amp; splits</td></tr>
                 <tr><td>End button</td><td>Clear saved layout; next visit starts fresh</td></tr>
+                <tr><td>Logout button</td><td>Sign out — workspace and all terminals are preserved; sign in again at the same URL to resume</td></tr>
                 <tr><td>Upload button</td><td>Upload file to server (lands in active shell's cwd by default)</td></tr>
                 <tr><td>Down button</td><td>Download file from server by path</td></tr>
             </table>
 
+            <div class="info-section-label">Session timeout</div>
+            <table class="info-table">
+                <tr><td>Auto-logout</td><td>30 minutes of inactivity signs you out automatically (workspace preserved)</td></tr>
+                <tr><td>Active sessions</td><td>Session extends automatically while you are active</td></tr>
+            </table>
+
         </div>
     </div>
 </div>