fix(ui): move Help nav link outside auth conditional so it shows for all visitors

Previously, duplicate Help links existed inside both branches of the
{% if multi_user_enabled and not is_logged_in %}...{% else %}...{% endif %}
conditional. This refactoring places a single Help link AFTER {% endif %}
in both the desktop and mobile menus, guaranteeing it renders for:
- Unauthenticated visitors (multi-user mode)
- Logged-in users (multi-user mode)
- All users in single-user / auth-disabled mode

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

frontend/templates/base.html

@@ -76,13 +76,6 @@
                {% if request and request.url.path == '/about' %}aria-current="page"{% endif %}>
               About
             </a>
-            <a href="/help/"
-               class="px-3 py-2 rounded-md text-sm font-medium text-gray-700 hover:text-gray-900 hover:bg-gray-100"
-               aria-label="Help and How-To Guides"
-               title="Help &amp; How-To Guides"
-               {% if request and request.url.path.startswith('/help') %}aria-current="page"{% endif %}>
-              <i class="fas fa-circle-question mr-1 text-gray-400" aria-hidden="true"></i>Help
-            </a>
 
             {% else %}
             {# ── App nav (logged-in or single-user / auth-disabled mode) ────── #}
@@ -178,7 +171,9 @@
               <i class="fas fa-circle-dot mr-0.5" aria-hidden="true"></i> Status
             </a>
 
-            <!-- Help documentation – visible to all users -->
+            {% endif %}{# end multi_user_enabled / is_logged_in check #}
+
+            <!-- Help – always visible, for every visitor regardless of auth state -->
             <a href="/help/"
                class="px-3 py-2 rounded-md text-sm font-medium text-gray-700 hover:text-gray-900 hover:bg-gray-100"
                aria-label="Help and How-To Guides"
@@ -187,8 +182,6 @@
               <i class="fas fa-circle-question mr-1 text-gray-400" aria-hidden="true"></i>Help
             </a>
 
-            {% endif %}{# end multi_user_enabled / is_logged_in check #}
-
             <!-- Dark mode toggle -->
             <button
               id="darkModeToggle"
@@ -245,12 +238,6 @@
                  {% if request and request.url.path == '/about' %}aria-current="page"{% endif %}>
                 <i class="fas fa-info-circle mr-2 text-gray-400" aria-hidden="true"></i>About
               </a>
-              <a href="/help/"
-                 class="block px-3 py-3 rounded-md text-base font-medium text-gray-700 hover:text-gray-900 hover:bg-gray-50"
-                 aria-label="Help and How-To Guides"
-                 {% if request and request.url.path.startswith('/help') %}aria-current="page"{% endif %}>
-                <i class="fas fa-circle-question mr-2 text-gray-400" aria-hidden="true"></i>Help
-              </a>
 
               {% else %}
               {# ── App links (logged-in or single-user) ────────────────────── #}
@@ -320,7 +307,9 @@
                 <i class="fas fa-circle-dot mr-1" aria-hidden="true"></i> Status
               </a>
 
-              <!-- Help documentation -->
+              {% endif %}{# end multi_user_enabled / is_logged_in check #}
+
+              <!-- Help – always visible, for every visitor regardless of auth state -->
               <a href="/help/"
                  class="block px-3 py-3 rounded-md text-base font-medium text-gray-700 hover:text-gray-900 hover:bg-gray-50"
                  aria-label="Help and How-To Guides"
@@ -328,8 +317,6 @@
                 <i class="fas fa-circle-question mr-2 text-gray-400" aria-hidden="true"></i>Help
               </a>
 
-              {% endif %}{# end multi_user_enabled / is_logged_in check #}
-
               <!-- Dark mode toggle (mobile) -->
               <button
                 onclick="toggleDarkMode()"