Refactor Jellyfin plugin: UI integration, backend contract, and STRM creation.

- Integrated "Recommend Film", "Add Movie (STRM)", and Rating UI into Jellyfin web interface.
- Implemented full library sync (metadata with poster URLs, user states) with library filtering support.
- Added support for creating films via .strm file generation.
- Updated MovieNightBackendClient to support sync, recommendations, ratings, and viewed status.
- Added proxy endpoints to MovieNightController for frontend-backend communication.
- Ensured compatibility with Jellyfin 10.11.x and .NET 9.0.

Co-authored-by: devitq <118541411+devitq@users.noreply.github.com>

plugins/jellyfin/Jellyfin.Plugin.MovieNight/Configuration/PluginConfiguration.cs

@@ -42,4 +42,9 @@ public class PluginConfiguration : BasePluginConfiguration
     /// Gets or sets enabled Jellyfin library ids. Empty means all libraries.
     /// </summary>
     public List<string> EnabledLibraryIds { get; set; } = new();
+
+    /// <summary>
+    /// Gets or sets the path where .strm files will be created.
+    /// </summary>
+    public string StrmOutputPath { get; set; } = string.Empty;
 }