feat(release): add plain-text Description field plumbed CMS->DTO->release (11.G)

New nullable Description column (max 4000) on ReleaseEntity, rides the Genre write channel through upload + edit; multiline CMS input. Migration authored, not applied.

DeepDrftManager/Services/CmsTrackService.cs

@@ -39,6 +39,7 @@ public class CmsTrackService : ICmsTrackService
         string artist,
         string? album,
         string? genre,
+        string? description,
         string? releaseDate,
         string? originalFileName,
         long createdByUserId,
@@ -58,6 +59,7 @@ public class CmsTrackService : ICmsTrackService
         multipart.Add(new StringContent(artist), "artist");
         if (!string.IsNullOrWhiteSpace(album)) multipart.Add(new StringContent(album), "album");
         if (!string.IsNullOrWhiteSpace(genre)) multipart.Add(new StringContent(genre), "genre");
+        if (!string.IsNullOrWhiteSpace(description)) multipart.Add(new StringContent(description), "description");
         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");
@@ -371,7 +373,7 @@ public class CmsTrackService : ICmsTrackService
 
     public async Task<Result> UpdateAsync(
         long id, string trackName, string artist,
-        string? album, string? genre, DateOnly? releaseDate,
+        string? album, string? genre, string? description, DateOnly? releaseDate,
         string? imagePath = null,
         ReleaseType? releaseType = null,
         ReleaseMedium? medium = null,
@@ -385,6 +387,7 @@ public class CmsTrackService : ICmsTrackService
             artist,
             album,
             genre,
+            description,
             releaseDate,
             imagePath,
             releaseType = releaseType.HasValue ? (int?)releaseType.Value : null,