feat: capture and display original upload filename for tracks

DeepDrftManager/Services/CmsTrackService.cs

@@ -39,6 +39,7 @@ public class CmsTrackService : ICmsTrackService
         string? album,
         string? genre,
         string? releaseDate,
+        string? originalFileName,
         long createdByUserId,
         CancellationToken ct = default)
     {
@@ -54,6 +55,8 @@ public class CmsTrackService : ICmsTrackService
         if (!string.IsNullOrWhiteSpace(album)) multipart.Add(new StringContent(album), "album");
         if (!string.IsNullOrWhiteSpace(genre)) multipart.Add(new StringContent(genre), "genre");
         if (!string.IsNullOrWhiteSpace(releaseDate)) multipart.Add(new StringContent(releaseDate), "releaseDate");
+        // Explicit field — decouples the admin-visible display name from the WAV part's content-disposition filename.
+        if (!string.IsNullOrWhiteSpace(originalFileName)) multipart.Add(new StringContent(originalFileName), "originalFileName");
         multipart.Add(new StringContent(createdByUserId.ToString()), "createdByUserId");
 
         var client = _httpClientFactory.CreateClient(ContentCmsClientName);