Update to refactor AuthorAliasRegistry, its sync and test.

lib/decentralised_book_index/metadata/author_alias_registry.ex

@@ -15,19 +15,11 @@ defmodule DecentralisedBookIndex.Metadata.AuthorAliasRegistry do
     defaults [:read, :create, :update, :destroy]
 
     create :sync_create do
-      accept [:id]
-
-      argument :dbi_server_id, :uuid do
-        allow_nil? false
-      end
+      accept [:id, :dbi_server_id]
     end
 
     update :sync do
-      accept [:id]
-
-      argument :dbi_server_id, :uuid do
-        allow_nil? false
-      end
+      accept [:id, :dbi_server_id]
     end
 
     read :by_id do

lib/decentralised_book_index/sync/sync/author_alias_registry_sync.ex

@@ -4,13 +4,13 @@ defmodule DecentralisedBookIndex.Sync.AuthorAliasRegistrySync do
 
   def create_update(attrs, server_id) do
     case Metadata.get_author_alias_registry_by_id(attrs.id) do
-      {:ok, author} ->
+      {:ok, alias_registry} ->
         attrs =
           attrs
           |> Map.delete(:id)
           |> Map.put(:dbi_server_id, server_id)
 
-        author
+        alias_registry
         |> Ash.Changeset.for_update(:sync, attrs)
         |> Ash.update!()