Performance: replace django-treenode with adjacency-list tags (#14612)

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Co-authored-by: Codex <267193182+codex@users.noreply.github.com>

src/documents/management/commands/document_importer.py

@@ -108,6 +108,24 @@ def _deserialize_record(
         ) from e
 
     for field_name, field_value in record.get("fields", {}).items():
+        # Older exports include django-treenode's derived bookkeeping. The
+        # parent FK is authoritative; accept only these known removed fields.
+        if Model is Tag and field_name in {
+            "tn_ancestors_count",
+            "tn_ancestors_pks",
+            "tn_children_count",
+            "tn_children_pks",
+            "tn_depth",
+            "tn_descendants_count",
+            "tn_descendants_pks",
+            "tn_index",
+            "tn_level",
+            "tn_order",
+            "tn_priority",
+            "tn_siblings_count",
+            "tn_siblings_pks",
+        }:
+            continue
         field = Model._meta.get_field(field_name)
         remote = field.remote_field