Add to installed apps, add to meta

src/documents/models.py

@@ -112,7 +112,7 @@ class Tag(MatchingModel, TreeNodeModel):
         ),
     )
 
-    class Meta(MatchingModel.Meta):
+    class Meta(MatchingModel.Meta, TreeNodeModel.Meta):
         verbose_name = _("tag")
         verbose_name_plural = _("tags")
 

src/paperless/settings.py

@@ -334,6 +334,7 @@ INSTALLED_APPS = [
     "allauth.mfa",
     "drf_spectacular",
     "drf_spectacular_sidecar",
+    "treenode",
     *env_apps,
 ]