Add :collection to chat entity enum

lib/music_library/chats/chat.ex

@@ -8,7 +8,7 @@ defmodule MusicLibrary.Chats.Chat do
   @primary_key {:id, :binary_id, autogenerate: true}
   @foreign_key_type :binary_id
   schema "chats" do
-    field :entity, Ecto.Enum, values: [:record, :artist]
+    field :entity, Ecto.Enum, values: [:record, :artist, :collection]
     field :musicbrainz_id, Ecto.UUID
     field :topic, :string
 

priv/repo/migrations/20260413090350_add_collection_entity_to_chats.exs

@@ -0,0 +1,8 @@
+defmodule MusicLibrary.Repo.Migrations.AddCollectionEntityToChats do
+  use Ecto.Migration
+
+  # The entity column is a plain string in SQLite — no CHECK constraint to alter.
+  # This migration documents the addition of the :collection entity type.
+  def change do
+  end
+end