fix: only show TOC shortcut key when TOC is enabled

Hide the 't' keyboard shortcut from the shortcuts overlay when
table of contents is not available (git mode, multi-file, or no
headings). Also make pressing 't' a no-op in those cases instead
of toggling a hidden element.

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

Author: tomasz-tomczyk

e2e/tests/keyboard.spec.ts

@@ -413,24 +413,13 @@ test.describe('Keyboard UI Toggles', () => {
     await expect(waitingOverlay).toHaveClass(/active/);
   });
 
-  test('t toggles table of contents (hidden in git mode, but toggles)', async ({ page }) => {
-    // In git mode, the tocToggle button is hidden (display: none), so pressing t clicks a hidden button.
-    // The toc starts with toc-hidden. Pressing t clicks the toggle button.
-    // Since the button is display:none in git mode, the click via keyboard shortcut
-    // still fires the click handler. Let's verify toc state changes.
+  test('t does nothing in git mode (TOC is disabled)', async ({ page }) => {
     const toc = page.locator('#toc');
 
     // Initially has toc-hidden
     await expect(toc).toHaveClass(/toc-hidden/);
 
-    // Press t
-    await page.keyboard.press('t');
-
-    // In git mode, the toggle button is hidden, but the 't' shortcut calls .click() on it,
-    // which should still toggle the class
-    await expect(toc).not.toHaveClass(/toc-hidden/);
-
-    // Press t again to close
+    // Press t — should be a no-op since TOC is hidden in git mode
     await page.keyboard.press('t');
     await expect(toc).toHaveClass(/toc-hidden/);
   });

frontend/app.js

@@ -3445,11 +3445,17 @@
     const tocEl = document.getElementById('toc');
     const listEl = tocEl.querySelector('.toc-list');
     const toggleBtn = document.getElementById('tocToggle');
+    const tocShortcut = document.querySelector('.shortcut-toc-only');
     listEl.innerHTML = '';
 
+    function hideToc() {
+      toggleBtn.style.display = 'none';
+      if (tocShortcut) tocShortcut.style.display = 'none';
+    }
+
     // TOC only for single-file markdown reviews
     if (session.mode === 'git' || files.length > 1) {
-      toggleBtn.style.display = 'none';
+      hideToc();
       return;
     }
 
@@ -3464,10 +3470,11 @@
     }
 
     if (allItems.length === 0) {
-      toggleBtn.style.display = 'none';
+      hideToc();
       return;
     }
     toggleBtn.style.display = '';
+    if (tocShortcut) tocShortcut.style.display = '';
 
     // Restore TOC open/closed state from cookie
     if (getCookie('crit-toc') === 'open') {
@@ -3802,8 +3809,10 @@
         break;
       }
       case 't': {
+        var tocBtn = document.getElementById('tocToggle');
+        if (tocBtn.style.display === 'none') return;
         e.preventDefault();
-        document.getElementById('tocToggle').click();
+        tocBtn.click();
         break;
       }
       case 'n': {

frontend/index.html

@@ -110,7 +110,7 @@ <h3>Keyboard Shortcuts</h3>
       <tr class="shortcut-filemode-only"><td><kbd>n</kbd></td><td>Next change</td></tr>
       <tr class="shortcut-filemode-only"><td><kbd>N</kbd></td><td>Previous change</td></tr>
       <tr><td><kbd>Shift</kbd>+<kbd>F</kbd></td><td>Finish review</td></tr>
-      <tr><td><kbd>t</kbd></td><td>Toggle table of contents</td></tr>
+      <tr class="shortcut-toc-only"><td><kbd>t</kbd></td><td>Toggle table of contents</td></tr>
       <tr><td><kbd>Esc</kbd></td><td>Cancel / clear focus</td></tr>
       <tr><td><kbd>Ctrl</kbd>+<kbd>Enter</kbd></td><td>Submit comment</td></tr>
       <tr><td><kbd>?</kbd></td><td>Toggle this help</td></tr>