🚨(linter) add missing docstrings

Title says all there is to say…

src/backend/core/api/permissions.py

@@ -12,13 +12,13 @@ class IsAuthenticated(permissions.BasePermission):
     """
 
     def has_permission(self, request, view):
+        """Check auth token first."""
         return bool(request.auth) if request.auth else request.user.is_authenticated
 
 
 class IsSelf(IsAuthenticated):
     """
-    Allows access only to authenticated users. Alternative method checking the presence
-    of the auth token to avoid hitting the database.
+    Allows access only to user's own data.
     """
 
     def has_object_permission(self, request, view, obj):

src/backend/core/api/serializers.py

@@ -34,6 +34,8 @@ class DynamicFieldsModelSerializer(serializers.ModelSerializer):
     """
 
     def __init__(self, *args, **kwargs):
+        """Pass arguments to superclass except 'fields', then drop fields not listed therein."""
+
         # Don't pass the 'fields' arg up to the superclass
         fields = kwargs.pop("fields", None)
 

src/backend/core/api/viewsets.py

@@ -340,6 +340,7 @@ class TeamAccessViewSet(
         return context
 
     def get_serializer_class(self):
+        """Chooses list or detail serializer according to the action."""
         if self.action in {"list", "retrieve"}:
             return self.list_serializer_class
         return self.detail_serializer_class