fix(activitypub): deduplicate account favourites

priv/repo/migrations/20260725000000_add_activity_favorites_lookup_index.exs

@@ -0,0 +1,20 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Repo.Migrations.AddActivityFavoritesLookupIndex do
+  use Ecto.Migration
+
+  @disable_ddl_transaction true
+  @disable_migration_lock true
+
+  def change do
+    create_if_not_exists(
+      index(:activities, [:actor, "associated_object_id(data)", "id DESC"],
+        name: :activities_favorites_lookup_index,
+        where: "data->>'type' = 'Like'",
+        concurrently: true
+      )
+    )
+  end
+end