fix: AI Editor section not visible — mismatched anchor #help-ia -> #help-ai

- TOC link and inline reference both pointed to #help-ia
- Actual section has id=help-ai
- Fixed both hrefs to match the section ID

frontend/index.html

@@ -2628,7 +2628,7 @@
                                 >
                             </li>
                             <li>
-                                <a href="#help-ia" class="help-nav-link"
+                                <a href="#help-ai" class="help-nav-link"
                                      data-i18n="help.nav_ai">🤖 IA Éditeur</a
                                 >
                             </li>
@@ -3318,7 +3318,7 @@
                                 <li>
                                     <strong data-i18n="help.toolbar_section">Barre d'outils AI</strong><span data-i18n="help.desc_c8532869"> :
                                     Complétion, réécriture, traduction (voir
-                                    section</span><a href="#help-ia" data-i18n="settings.ai">🤖 IA</a>)
+                                    section</span><a href="#help-ai" data-i18n="settings.ai">🤖 IA</a>)
                                 </li>
                             </ul>
                         </section>