feat: capture and display original upload filename for tracks

DeepDrftManager/Services/ICmsTrackService.cs

@@ -15,6 +15,8 @@ public interface ICmsTrackService
     /// Proxy a WAV upload to DeepDrftAPI. The Content API owns the dual-database write and
     /// returns the persisted track carrying the SQL-assigned <c>Id</c>. A vault-without-SQL
     /// orphan is handled and logged server-side; here it surfaces as a failed result.
+    /// <paramref name="originalFileName"/> is the browser's filename, captured at upload time and
+    /// stored as metadata; it is not user-editable afterwards.
     /// </summary>
     Task<ResultContainer<TrackDto>> UploadTrackAsync(
         Stream wavStream,
@@ -25,6 +27,7 @@ public interface ICmsTrackService
         string? album,
         string? genre,
         string? releaseDate,
+        string? originalFileName,
         long createdByUserId,
         CancellationToken ct = default);