Reorganize backend to mirror Musify.slnx folder structure

Moves the six backend projects on disk into Core/ and Hosts/
subfolders, matching the solution folders already defined in
Musify.slnx, so the file explorer reflects the same layout as the
solution:

  backend/Core/Musify.Domain
  backend/Core/Musify.Application
  backend/Core/Musify.Infrastructure
  backend/Hosts/Musify.Api
  backend/Hosts/Musify.Worker
  backend/Hosts/Musify.StreamingGateway

Updates every reference to the old paths: ProjectReference entries in
Musify.Api.csproj and Musify.Worker.csproj, the three Dockerfiles,
deploy/scripts/migrate.ps1|sh, deploy/zitadel/provision.ps1,
deploy/up.ps1, deploy/README.md and docs/development.md. Also fixes a
stale Dockerfile comment pointing at a compose file that no longer
exists.

Verified with `dotnet build Musify.slnx` against the new layout.

backend/Core/Musify.Infrastructure/MassTransit/Arguments/ConsumeUploadIntentsArguments.cs

@@ -0,0 +1,5 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record ConsumeUploadIntentsArguments(
+        Guid[] IntentIds);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/CopyFileInBucketArguments.cs

@@ -0,0 +1,8 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record CopyFileInBucketArguments(
+        string SourceBucket,
+        string SourceKey,
+        string DestinationBucket,
+        string DestinationKey);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/DeletePlayListFromDbArguments.cs

@@ -0,0 +1,5 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    internal record DeletePlayListFromDbArguments(
+        Guid PlayListId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/DeleteTrackFromDbArguments.cs

@@ -0,0 +1,5 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    internal record DeleteTrackFromDbArguments(
+        Guid TrackId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/DownloadFileFromBucketArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record DownloadFileFromBucketArguments(
+        string Bucket,
+        string Key,
+        string DestinationFilePathVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/DownloadFileFromUrlArguments.cs

@@ -0,0 +1,6 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record DownloadFileFromUrlArguments(
+        string SourceUrl,
+        string DestinationFilePathVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/DownloadYouTubeAudioArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record DownloadYouTubeAudioArguments(
+        Guid TrackId,
+        string VideoId,
+        string DestinationFilePathVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/GenerateAudioWorkflowPathsArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record GenerateAudioWorkflowPathsArguments(
+        Guid TrackId,
+        string TemporaryRootDirectory,
+        string SourceKey);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/GeneratePictureWorkflowPathsArguments.cs

@@ -0,0 +1,6 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record GeneratePictureWorkflowPathsArguments(
+        string TemporaryRootDirectory,
+        string SourceKey);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/MarkPlayListAsFailedArguments.cs

@@ -0,0 +1,4 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record MarkPlayListAsFailedArguments(Guid PlayListId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/MarkPlayListAsRemovingArguments.cs

@@ -0,0 +1,5 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    internal record MarkPlayListAsRemovingArguments(
+        Guid PlayListId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/MarkTrackAsFailedArguments.cs

@@ -0,0 +1,4 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record MarkTrackAsFailedArguments(Guid TrackId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/MarkTrackAsRemovingArguments.cs

@@ -0,0 +1,5 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    internal record MarkTrackAsRemovingArguments(
+        Guid TrackId);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/PublishPlayListPictureProcessingEventArguments.cs

@@ -0,0 +1,12 @@
+using Musify.Application.Shared;
+
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record PublishPlayListPictureProcessingEventArguments(
+        Guid PlayListId,
+        string Bucket,
+        string FinalPictureKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/PublishTrackProcessingEventsArguments.cs

@@ -0,0 +1,14 @@
+using Musify.Application.Shared;
+
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record PublishTrackProcessingEventsArguments(
+        Guid TrackId,
+        string Bucket,
+        string FinalPictureKey,
+        string FinalAudioKey,
+        string AudioDestinationFolderKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/RemoveFileFromBucketArguments.cs

@@ -0,0 +1,6 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record RemoveFileFromBucketArguments(
+        string Bucket,
+        string Key);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/ResizePictureLocalArguments.cs

@@ -0,0 +1,8 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record ResizePictureLocalArguments(
+        string SourceFilePathVariable,
+        string DestinationFilePathVariable,
+        int Width,
+        int Height);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/TranscodeAudioArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record TranscodeAudioArguments(
+        Guid TrackId,
+        string SourceFilePathVariable,
+        string WorkingDirectoryVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/TransferFilesToBucketArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record TransferFilesToBucketArguments(
+        string DestinationBucket,
+        string SourceDirectoryVariable,
+        string DestinationKey);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/UpdatePlayListPictureArguments.cs

@@ -0,0 +1,9 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record UpdatePlayListPictureArguments(
+        Guid PlayListId,
+        string OriginalPictureKey,
+        string SmallPictureVariable,
+        string MediumPictureVariable,
+        string LargePictureVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/UpdateTrackAudioArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record UpdateTrackAudioArguments(
+        Guid TrackId,
+        string AudioFolderKey,
+        string DurationSecondsVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/UpdateTrackPictureArguments.cs

@@ -0,0 +1,9 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record UpdateTrackPictureArguments(
+        Guid TrackId,
+        string OriginalPictureKey,
+        string SmallPictureVariable,
+        string MediumPictureVariable,
+        string LargePictureVariable);
+}

backend/Core/Musify.Infrastructure/MassTransit/Arguments/UploadFileToBucketArguments.cs

@@ -0,0 +1,7 @@
+namespace Musify.Infrastructure.MassTransit.Arguments
+{
+    public record UploadFileToBucketArguments(
+        string FilePathVariable,
+        string DestinationBucket,
+        string DestinationRoute);
+}