Fix movie recommendations

MediaBrowser.Controller/Library/IBatchLocalSimilarItemsProvider.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Library;
+
+/// <summary>
+/// A local similar items provider that supports batch queries across multiple source items.
+/// Implementations share access filtering and entity loading across all sources for better performance.
+/// </summary>
+public interface IBatchLocalSimilarItemsProvider : ISimilarItemsProvider
+{
+    /// <summary>
+    /// Gets similar items for multiple source items in a single batch.
+    /// </summary>
+    /// <param name="sourceItems">The source items to find similar items for.</param>
+    /// <param name="query">The query options.</param>
+    /// <returns>Per-source-item results keyed by source item ID.</returns>
+    Task<Dictionary<Guid, IReadOnlyList<BaseItem>>> GetBatchSimilarItemsAsync(
+        IReadOnlyList<BaseItem> sourceItems,
+        SimilarItemsQuery query);
+}