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)

dokumente/views.py

@@ -392,3 +392,31 @@ def user_comments(request):
         'comments_by_document': comments_by_document,
         'total_comments': user_comments.count(),
     })
+
+
+@login_required
+@user_passes_test(is_staff_user)
+def all_comments(request):
+    """
+    Display all comments from all users, grouped by document.
+    Staff only.
+    """
+    # Get all comments
+    all_comments_qs = VorgabeComment.objects.select_related(
+        'vorgabe', 'vorgabe__dokument', 'user'
+    ).order_by(
+        'vorgabe__dokument__nummer', '-created_at'
+    )
+    
+    # Group comments by document
+    comments_by_document = {}
+    for comment in all_comments_qs:
+        dokument = comment.vorgabe.dokument
+        if dokument not in comments_by_document:
+            comments_by_document[dokument] = []
+        comments_by_document[dokument].append(comment)
+    
+    return render(request, 'standards/all_comments.html', {
+        'comments_by_document': comments_by_document,
+        'total_comments': all_comments_qs.count(),
+    })