ML-168: broadcast index_changed event after background import

Import workers now broadcast :records_index_changed on
"records:index_changed" after successful import via
Records.broadcast_index_changed/0.

CollectionLive.Index and WishlistLive.Index subscribe to the
topic in mount/3 and reload their record streams on receipt,
with a live_action guard to skip reloads when the grid is
hidden behind a modal (:import, :barcode_scan).

IndexActions.handle_index_changed/1 refreshes total_entries
before reloading to keep the pagination bar accurate.

test/music_library_web/live/collection_live/index_test.exs

@@ -12,6 +12,7 @@ defmodule MusicLibraryWeb.CollectionLive.IndexTest do
   alias MusicLibrary.Assets.{Image, Transform}
   alias MusicLibrary.Records.Record
   alias MusicLibrary.Worker.ImportFromMusicbrainzReleaseGroup
+  alias Phoenix.LiveViewTest
   alias Req.Test
 
   # make it a multiple of 4 for easier calculations
@@ -93,6 +94,37 @@ defmodule MusicLibraryWeb.CollectionLive.IndexTest do
     end
   end
 
+  describe "PubSub index_changed" do
+    test "reloads stream when live_action is :index", %{conn: conn} do
+      {:ok, view, _html} = LiveViewTest.live(conn, ~p"/collection")
+
+      html_before = LiveViewTest.render(view)
+
+      # Create a new record behind the scenes (simulating completed background import)
+      _new_record = record()
+
+      # Send the index_changed message directly
+      send(view.pid, :records_index_changed)
+
+      # The view should now include the new record
+      html_after = LiveViewTest.render(view)
+      assert html_after != html_before
+    end
+
+    test "ignores message when live_action is :import (guard clause)", %{conn: conn} do
+      {:ok, view, _html} = LiveViewTest.live(conn, ~p"/collection/import")
+
+      html_before = LiveViewTest.render(view)
+
+      send(view.pid, :records_index_changed)
+
+      html_after = LiveViewTest.render(view)
+
+      # Should be identical — the message is a no-op when grid is behind modal
+      assert html_after == html_before
+    end
+  end
+
   describe "Search and pagination" do
     setup [:fill_collection]
 

test/music_library_web/live/wishlist_live/index_test.exs

@@ -9,6 +9,7 @@ defmodule MusicLibraryWeb.WishlistLive.IndexTest do
 
   alias MusicLibrary.Records.Record
   alias MusicLibrary.Worker.ImportFromMusicbrainzReleaseGroup
+  alias Phoenix.LiveViewTest
   alias Req.Test
 
   defp fill_wishlist(_) do
@@ -16,6 +17,37 @@ defmodule MusicLibraryWeb.WishlistLive.IndexTest do
     %{wishlist: records}
   end
 
+  describe "PubSub index_changed" do
+    test "reloads stream when live_action is :index", %{conn: conn} do
+      {:ok, view, _html} = LiveViewTest.live(conn, ~p"/wishlist")
+
+      html_before = LiveViewTest.render(view)
+
+      # Create a new wishlist record behind the scenes (simulating completed background import)
+      _new_record = record(%{purchased_at: nil})
+
+      # Send the index_changed message directly
+      send(view.pid, :records_index_changed)
+
+      # The view should now include the new record
+      html_after = LiveViewTest.render(view)
+      assert html_after != html_before
+    end
+
+    test "ignores message when live_action is :import (guard clause)", %{conn: conn} do
+      {:ok, view, _html} = LiveViewTest.live(conn, ~p"/wishlist/import")
+
+      html_before = LiveViewTest.render(view)
+
+      send(view.pid, :records_index_changed)
+
+      html_after = LiveViewTest.render(view)
+
+      # Should be identical — the message is a no-op when grid is behind modal
+      assert html_after == html_before
+    end
+  end
+
   describe "Wishlist" do
     setup [:fill_wishlist]