Add staff-only all comments page and bump versions

- Add new "alle-kommentare" (all comments) view for staff users only
  - Allows staff to view and manage all user comments across the system
  - Grouped by document with user information displayed
  - Staff can delete any comment via the dedicated delete button
  - Restricts access via user_passes_test decorator

- Create all_comments.html template
  - Based on user_comments template with added username field
  - Shows comment author, creation time, and edit time
  - Provides delete functionality for comment management

- Update navigation menu
  - Add "Alle Kommentare" link in user dropdown menu
  - Link only visible to staff members

- Add URL route for alle-kommentare page
  - Path: /dokumente/alle-kommentare/
  - URL name: all_comments

- Bump application versions
  - Update footer version from 0.965 to 0.966
  - Update K8s deployment version from 0.917 to 0.918
  - ArgoCD deployment already at 0.966

All existing tests pass (148 tests total)

pages/templates/base.html

@@ -52,18 +52,21 @@
           <span class="caret" style="margin-left: 8px;"></span>
         </a>
          <ul class="dropdown-menu dropdown-menu-right" role="menu">
-           <li><a href="{% url 'user_comments' %}">Meine Kommentare</a></li>
-           <li><a href="{% url 'password_change' %}">Passwort ändern</a></li>
-           <li class="divider"></li>
-           <li>
-             <form method="post" action="{% url 'logout' %}" style="display: inline;">
-               {% csrf_token %}
-               <button type="submit" style="background: none; border: none; color: inherit; padding: 3px 20px; width: 100%; text-align: left; cursor: pointer;">
-                 Abmelden
-               </button>
-             </form>
-           </li>
-         </ul>
+            <li><a href="{% url 'user_comments' %}">Meine Kommentare</a></li>
+            {% if user.is_staff %}
+            <li><a href="{% url 'all_comments' %}">Alle Kommentare</a></li>
+            {% endif %}
+            <li><a href="{% url 'password_change' %}">Passwort ändern</a></li>
+            <li class="divider"></li>
+            <li>
+              <form method="post" action="{% url 'logout' %}" style="display: inline;">
+                {% csrf_token %}
+                <button type="submit" style="background: none; border: none; color: inherit; padding: 3px 20px; width: 100%; text-align: left; cursor: pointer;">
+                  Abmelden
+                </button>
+              </form>
+            </li>
+          </ul>
       </div>
     </div>
     {% else %}
@@ -216,8 +219,8 @@
           </p>
         </div>
         <div class="col-sm-6 text-right">
-          <p class="text-muted">Version {{ version|default:"0.965" }}</p>
-        </div>
+           <p class="text-muted">Version {{ version|default:"0.966" }}</p>
+         </div>
       </div>
     </div>
   </footer>