Clean up Application layer commands/queries readability and correctness

Add missing AsNoTracking() on read-only queries, drop redundant
Update() calls on already-tracked entities, and fix inconsistent
formatting (stray spaces in generics, ternaries, and lambdas) across
the Albums/Tracks/PlayLists/Users command and query handlers.

backend/Core/Musify.Application/PlayLists/CreatePlayList.cs

@@ -55,7 +55,7 @@ namespace Musify.Application.PlayLists
                 UserId = request.UserId,
                 Name = request.Name,
                 NormalizedName = request.Name.Trim().ToUpperInvariant(),
-                Description = string.IsNullOrWhiteSpace(request.Description)? null: request.Description.Trim(),
+                Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim(),
                 Pictures = resolvedPictures.Pictures,
                 Visibility = request.Visibility
             };
@@ -106,7 +106,7 @@ namespace Musify.Application.PlayLists
             }, validation.Value);
         }
 
-        async Task<ErrorOr<Success>> PublishCreatePlayListEventAsync(
+        private async Task<ErrorOr<Success>> PublishCreatePlayListEventAsync(
             Guid playListId,
             UploadIntent pictureIntent,
             string finalPictureKey,

backend/Core/Musify.Application/PlayLists/GetPlayListTracks.cs

@@ -16,9 +16,9 @@ namespace Musify.Application.PlayLists
         : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
 
     public class GetPlayListTracksQueryHandler(IDatabase database)
-        : IQueryHandler<GetPlayListTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>> >
+        : IQueryHandler<GetPlayListTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
     {
-        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse> >> Handle(GetPlayListTracksQuery request, CancellationToken cancellationToken)
+        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetPlayListTracksQuery request, CancellationToken cancellationToken)
         {
             var playListExists = await database.PlayLists
                 .AsNoTracking()

backend/Core/Musify.Application/PlayLists/GetPlayLists.cs

@@ -10,12 +10,12 @@ using Musify.Application.Contracts;
 namespace Musify.Application.PlayLists
 {
     public record GetPlayListsQuery(int PageNumber, int PageSize)
-        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>> >;
+        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>;
 
     public class GetPlayListsQueryHandler(IDatabase database)
-        : IQueryHandler<GetPlayListsQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse> >>
+        : IQueryHandler<GetPlayListsQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>
     {
-        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse> >> Handle(GetPlayListsQuery request, CancellationToken cancellationToken)
+        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>> Handle(GetPlayListsQuery request, CancellationToken cancellationToken)
         {
             var totalCount = await database.PlayLists.CountAsync(cancellationToken);
 

backend/Core/Musify.Application/PlayLists/GetPlayListsByUserId.cs

@@ -16,12 +16,12 @@ namespace Musify.Application.PlayLists
         int PageNumber,
         int PageSize,
         bool OnlyPublic = false)
-        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>> >;
+        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>;
 
     public class GetPlayListsByUserIdQueryHandler(IDatabase database)
-        : IQueryHandler<GetPlayListsByUserIdQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse> > >
+        : IQueryHandler<GetPlayListsByUserIdQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>
     {
-        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse> >> Handle(GetPlayListsByUserIdQuery request, CancellationToken cancellationToken)
+        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>> Handle(GetPlayListsByUserIdQuery request, CancellationToken cancellationToken)
         {
             var playListsQuery = database.PlayLists
                 .AsNoTracking()
@@ -51,7 +51,7 @@ namespace Musify.Application.PlayLists
                         .Take(PlayListApplicationResponse.CoverTrackCount)
                         .Select(plt => plt.TrackId)
                         .ToList()
-                } )
+                })
                 .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
 
             var pagedPlayLists = new StaticPagedList<PlayListApplicationResponse>(

backend/Core/Musify.Application/PlayLists/RequestPlayListPictureUpload.cs

@@ -42,7 +42,7 @@ namespace Musify.Application.PlayLists
             var effectiveSizeBytes = request.ExpectedSizeBytes
                 ?? uploadIntentConfiguration.DefaultExpectedPictureSizeBytes;
 
-            var objectName = $"{Guid.NewGuid() }.{request.FileType.TrimStart('.').ToLowerInvariant() }";
+            var objectName = $"{Guid.NewGuid()}.{request.FileType.TrimStart('.').ToLowerInvariant()}";
 
             var tempKey = playListConfiguration.Routes.BuildTempPicturePath(
                 uploadIntentConfiguration.TemporalRootPrefix, request.UserId, objectName);
@@ -84,7 +84,7 @@ namespace Musify.Application.PlayLists
                 await database.SaveChangesAsync(cancellationToken);
                 await transaction.CommitAsync(cancellationToken);
 
-                logger.LogInformation("Issued upload intent {IntentId} for user {UserId} (PlayListPicture, temp key: {Key} )", intent.Id, request.UserId, tempKey);
+                logger.LogInformation("Issued upload intent {IntentId} for user {UserId} (PlayListPicture, temp key: {Key})", intent.Id, request.UserId, tempKey);
 
                 return new PlayListPictureUploadResponse(
                     intent.Id,

backend/Core/Musify.Application/PlayLists/UpdatePlayList.cs

@@ -85,9 +85,7 @@ namespace Musify.Application.PlayLists
                 finalPictureKey = playListConfiguration.Routes.BuildOriginalPicturePath(request.UserId, pictureIntent.ObjectName);
             }
 
-            database.PlayLists.Update(playListEntity);
-
-            if (pictureIntent != null&& finalPictureKey != null)
+            if (pictureIntent != null && finalPictureKey != null)
             {
                 var publishResult = await PublishUpdatePlayListPictureSourceEventAsync(
                     playListEntity.Id, pictureIntent, finalPictureKey, cancellationToken);
@@ -117,7 +115,7 @@ namespace Musify.Application.PlayLists
             return PlayListApplicationResponse.FromEntity(playListEntity, coverTrackIds);
         }
 
-        async Task<ErrorOr<Success>> PublishUpdatePlayListPictureSourceEventAsync(
+        private async Task<ErrorOr<Success>> PublishUpdatePlayListPictureSourceEventAsync(
             Guid playListId,
             UploadIntent pictureIntent,
             string finalPictureKey,