fix: use CiStringWrapper type in ash_postgres

lib/data_layer.ex

@@ -1601,6 +1601,10 @@ defmodule AshPostgres.DataLayer do
     {:array, parameterized_type(type, constraints[:items] || [])}
   end
 
+  defp parameterized_type(Ash.Type.CiString, constraints) do
+    parameterized_type(Ash.Type.CiStringWrapper, constraints)
+  end
+
   defp parameterized_type(type, constraints) do
     if Ash.Type.ash_type?(type) do
       parameterized_type(Ash.Type.ecto_type(type), constraints)

lib/types/ci_string_wrapper.ex

@@ -0,0 +1,14 @@
+defmodule Ash.Type.CiStringWrapper do
+  @moduledoc false
+  use Ash.Type
+
+  @impl true
+  def storage_type, do: :citext
+
+  @impl true
+  defdelegate cast_input(value, constraints), to: Ash.Type.CiString
+  @impl true
+  defdelegate cast_stored(value, constraints), to: Ash.Type.CiString
+  @impl true
+  defdelegate dump_to_native(value, constraints), to: Ash.Type.CiString
+end

test/support/resources/comment.ex

@@ -30,6 +30,10 @@ defmodule AshPostgres.Test.Comment do
     create_timestamp(:created_at)
   end
 
+  aggregates do
+    first(:post_category, :post, :category)
+  end
+
   relationships do
     belongs_to(:post, AshPostgres.Test.Post)
     belongs_to(:author, AshPostgres.Test.Author)