feat(infra): add Track processing saga (state machine, phase 1)

Introduce a MassTransit saga state machine that correlates by TrackId and
tracks the two parallel processing slips (picture + audio):
- TrackProcessingStateMachine + EF-persisted TrackProcessingState
  (pessimistic concurrency, EntityFrameworkRepository), migration added
- Starts on CreateTrackResourcesEvent; UpdateTrack{Picture,Audio}Activity now
  publish TrackPictureProcessed / TrackAudioProcessed on success; when both
  arrive the saga finalizes (Ready). Failure transitions to a Failed state
  (cleanup wired in the next phase)
- Add LifeCycleStatus.Failed and the four outcome events

Verified: booted the Worker against RabbitMQ + migrated Postgres in Docker;
the saga endpoint 'track-processing-state' is configured and the bus starts
clean.

Build: 0 warnings, 0 errors.

backend/Musify.Infrastructure/MassTransit/Activities/Audio/UpdateTrackAudioActivity.cs

@@ -2,6 +2,7 @@ using MassTransit;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
+using Musify.Application.Events;
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
 using Musify.Infrastructure.MassTransit.Arguments;
@@ -11,6 +12,7 @@ namespace Musify.Infrastructure.MassTransit.Activities.Audio
 {
     internal class UpdateTrackAudioActivity(
         IDatabase database,
+        IPublishEndpoint publishEndpoint,
         ILogger<UpdateTrackAudioActivity> logger)
         : IActivity<UpdateTrackAudioArguments, UpdateTrackAudioLog>
     {
@@ -37,6 +39,9 @@ namespace Musify.Infrastructure.MassTransit.Activities.Audio
             if (string.IsNullOrWhiteSpace(audioFolderKey))
             {
                 logger.LogWarning("Audio folder key is empty for track {TrackId}; skipping update", track.Id);
+                await publishEndpoint.Publish(
+                    new TrackAudioProcessed(executeContext.Arguments.TrackId),
+                    executeContext.CancellationToken);
                 return executeContext.Completed();
             }
 
@@ -52,6 +57,10 @@ namespace Musify.Infrastructure.MassTransit.Activities.Audio
 
                 logger.LogInformation("Updated track {TrackId} audio", executeContext.Arguments.TrackId);
 
+                await publishEndpoint.Publish(
+                    new TrackAudioProcessed(executeContext.Arguments.TrackId),
+                    executeContext.CancellationToken);
+
                 return executeContext.Completed(log);
             }
             catch (Exception exception)

backend/Musify.Infrastructure/MassTransit/Activities/Pictures/UpdateTrackPictureActivity.cs

@@ -1,6 +1,7 @@
 using MassTransit;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
+using Musify.Application.Events;
 using Musify.Domain.ValueObjects;
 using Musify.Infrastructure.MassTransit.Arguments;
 using Musify.Infrastructure.MassTransit.Logs;
@@ -9,6 +10,7 @@ namespace Musify.Infrastructure.MassTransit.Activities.Pictures
 {
     internal class UpdateTrackPictureActivity(
         IDatabase database,
+        IPublishEndpoint publishEndpoint,
         ILogger<UpdateTrackPictureActivity> logger)
         : IActivity<UpdateTrackPictureArguments, UpdateTrackPictureLog>
     {
@@ -55,6 +57,10 @@ namespace Musify.Infrastructure.MassTransit.Activities.Pictures
                 logger.LogInformation("Updated track {TrackId} pictures",
                     executeContext.Arguments.TrackId);
 
+                await publishEndpoint.Publish(
+                    new TrackPictureProcessed(executeContext.Arguments.TrackId),
+                    executeContext.CancellationToken);
+
                 return executeContext.Completed();
             }
             catch (Exception exception)

backend/Musify.Infrastructure/MassTransit/DependencyInjection/MassTransitDependencyInjection.cs

@@ -3,6 +3,7 @@ using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Musify.Application.Contracts;
 using Musify.Infrastructure.Configuration;
+using Musify.Infrastructure.MassTransit.Sagas;
 using Musify.Infrastructure.Persistence;
 
 namespace Musify.Infrastructure.MassTransit
@@ -66,6 +67,14 @@ namespace Musify.Infrastructure.MassTransit
 
                 RegisterConsumersAndActivities(options);
 
+                options.AddSagaStateMachine<TrackProcessingStateMachine, TrackProcessingState>()
+                    .EntityFrameworkRepository(repository =>
+                    {
+                        repository.ConcurrencyMode = ConcurrencyMode.Pessimistic;
+                        repository.ExistingDbContext<Database>();
+                        repository.UsePostgres();
+                    });
+
                 options.AddConfigureEndpointsCallback((registrationContext, _, endpointConfigurator) =>
                 {
                     UseStandardRetry(endpointConfigurator);

backend/Musify.Infrastructure/MassTransit/Sagas/TrackProcessingState.cs

@@ -0,0 +1,19 @@
+using MassTransit;
+
+namespace Musify.Infrastructure.MassTransit.Sagas
+{
+    public class TrackProcessingState : SagaStateMachineInstance
+    {
+        public Guid CorrelationId { get; set; }
+
+        public string CurrentState { get; set; } = null!;
+
+        public bool PictureProcessed { get; set; }
+
+        public bool AudioProcessed { get; set; }
+
+        public DateTime CreatedAt { get; set; }
+
+        public DateTime UpdatedAt { get; set; }
+    }
+}

backend/Musify.Infrastructure/MassTransit/Sagas/TrackProcessingStateMachine.cs

@@ -0,0 +1,67 @@
+using MassTransit;
+using Musify.Application.Events;
+
+namespace Musify.Infrastructure.MassTransit.Sagas
+{
+    public sealed class TrackProcessingStateMachine : MassTransitStateMachine<TrackProcessingState>
+    {
+        public State Processing { get; private set; } = null!;
+        public State Failed { get; private set; } = null!;
+
+        public Event<CreateTrackResourcesEvent> ProcessingStarted { get; private set; } = null!;
+        public Event<TrackPictureProcessed> PictureProcessed { get; private set; } = null!;
+        public Event<TrackAudioProcessed> AudioProcessed { get; private set; } = null!;
+        public Event<TrackPictureProcessingFailed> PictureFailed { get; private set; } = null!;
+        public Event<TrackAudioProcessingFailed> AudioFailed { get; private set; } = null!;
+
+        public TrackProcessingStateMachine()
+        {
+            InstanceState(state => state.CurrentState);
+
+            Event(() => ProcessingStarted, config => config.CorrelateById(context => context.Message.TrackId));
+            Event(() => PictureProcessed, config => config.CorrelateById(context => context.Message.TrackId));
+            Event(() => AudioProcessed, config => config.CorrelateById(context => context.Message.TrackId));
+            Event(() => PictureFailed, config => config.CorrelateById(context => context.Message.TrackId));
+            Event(() => AudioFailed, config => config.CorrelateById(context => context.Message.TrackId));
+
+            Initially(
+                When(ProcessingStarted)
+                    .Then(context =>
+                    {
+                        context.Saga.CreatedAt = DateTime.UtcNow;
+                        context.Saga.UpdatedAt = DateTime.UtcNow;
+                    })
+                    .TransitionTo(Processing));
+
+            During(Processing,
+                When(PictureProcessed)
+                    .Then(context =>
+                    {
+                        context.Saga.PictureProcessed = true;
+                        context.Saga.UpdatedAt = DateTime.UtcNow;
+                    })
+                    .If(context => context.Saga.AudioProcessed, binder => binder.Finalize()),
+                When(AudioProcessed)
+                    .Then(context =>
+                    {
+                        context.Saga.AudioProcessed = true;
+                        context.Saga.UpdatedAt = DateTime.UtcNow;
+                    })
+                    .If(context => context.Saga.PictureProcessed, binder => binder.Finalize()),
+                When(PictureFailed)
+                    .Then(context => context.Saga.UpdatedAt = DateTime.UtcNow)
+                    .TransitionTo(Failed),
+                When(AudioFailed)
+                    .Then(context => context.Saga.UpdatedAt = DateTime.UtcNow)
+                    .TransitionTo(Failed));
+
+            During(Failed,
+                Ignore(PictureProcessed),
+                Ignore(AudioProcessed),
+                Ignore(PictureFailed),
+                Ignore(AudioFailed));
+
+            SetCompletedWhenFinalized();
+        }
+    }
+}

backend/Musify.Infrastructure/Persistence/Database.cs

@@ -3,6 +3,7 @@ using Microsoft.EntityFrameworkCore.Storage;
 using MassTransit;
 using Musify.Domain.Entities;
 using Musify.Infrastructure.Configuration;
+using Musify.Infrastructure.MassTransit.Sagas;
 using AppIDatabase = Musify.Application.Contracts.IDatabase;
 using Musify.Application.Contracts;
 
@@ -24,6 +25,11 @@ namespace Musify.Infrastructure.Persistence
             modelBuilder.AddInboxStateEntity();
             modelBuilder.AddOutboxMessageEntity();
             modelBuilder.AddOutboxStateEntity();
+
+            var trackProcessing = modelBuilder.Entity<TrackProcessingState>();
+            trackProcessing.HasKey(state => state.CorrelationId);
+            trackProcessing.Property(state => state.CorrelationId).ValueGeneratedNever();
+            trackProcessing.Property(state => state.CurrentState).HasMaxLength(64);
         }
 
         public DbSet<User> Users => Set<User>();

backend/Musify.Infrastructure/Persistence/Migrations/20260705123932_AddTrackProcessingStateSaga.Designer.cs

@@ -0,0 +1,610 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Musify.Infrastructure.Persistence;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace Musify.Infrastructure.Persistence.Migrations
+{
+    [DbContext(typeof(Database))]
+    [Migration("20260705123932_AddTrackProcessingStateSaga")]
+    partial class AddTrackProcessingStateSaga
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.8")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.InboxState", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime?>("Consumed")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("ConsumerId")
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime?>("Delivered")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime?>("ExpirationTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long?>("LastSequenceNumber")
+                        .HasColumnType("bigint");
+
+                    b.Property<Guid>("LockId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("MessageId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int>("ReceiveCount")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime>("Received")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<byte[]>("RowVersion")
+                        .IsConcurrencyToken()
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("bytea");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Delivered");
+
+                    b.ToTable("InboxState");
+                });
+
+            modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.OutboxMessage", b =>
+                {
+                    b.Property<long>("SequenceNumber")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("SequenceNumber"));
+
+                    b.Property<string>("Body")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("ContentType")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<Guid?>("ConversationId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid?>("CorrelationId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("DestinationAddress")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<DateTime?>("EnqueueTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime?>("ExpirationTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("FaultAddress")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("Headers")
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("InboxConsumerId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid?>("InboxMessageId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid?>("InitiatorId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("MessageId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("MessageType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("OutboxId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Properties")
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("RequestId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("ResponseAddress")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<DateTime>("SentTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("SourceAddress")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.HasKey("SequenceNumber");
+
+                    b.HasIndex("EnqueueTime");
+
+                    b.HasIndex("ExpirationTime");
+
+                    b.HasIndex("OutboxId", "SequenceNumber")
+                        .IsUnique();
+
+                    b.HasIndex("InboxMessageId", "InboxConsumerId", "SequenceNumber")
+                        .IsUnique();
+
+                    b.ToTable("OutboxMessage");
+                });
+
+            modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.OutboxState", b =>
+                {
+                    b.Property<Guid>("OutboxId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("Created")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime?>("Delivered")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long?>("LastSequenceNumber")
+                        .HasColumnType("bigint");
+
+                    b.Property<Guid>("LockId")
+                        .HasColumnType("uuid");
+
+                    b.Property<byte[]>("RowVersion")
+                        .IsConcurrencyToken()
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("bytea");
+
+                    b.HasKey("OutboxId");
+
+                    b.HasIndex("Created");
+
+                    b.ToTable("OutboxState");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.PlayList", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("LargePictureName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<int>("LifeCycleStatus")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("MediumPictureName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("NormalizedName")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("OriginalPictureName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("SmallPictureName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("PlayLists");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.PlayListHasTrack", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("AddedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("PlayListId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int>("Position")
+                        .HasColumnType("integer");
+
+                    b.Property<Guid>("TrackId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PlayListId");
+
+                    b.HasIndex("TrackId");
+
+                    b.ToTable("PlayListHasTrack");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.Track", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("AudioFolderName")
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<int>("AudioTranscodeProcessingStatus")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("LargePictureName")
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTime?>("LastRetryAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("LifeCycleStatus")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("MediumPictureName")
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("NormalizedTitle")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("OriginalAudioName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("OriginalPictureName")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<int>("PicturesProcessingStatus")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("RetryCount")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("SmallPictureName")
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Tracks");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.Upload", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Bucket")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("ContentType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTime>("CreatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("State")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Upload");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.UploadIntent", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Bucket")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<string>("ContentType")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long?>("ExpectedSizeBytes")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime>("ExpiresAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)");
+
+                    b.Property<string>("ObjectName")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<int>("Purpose")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("UploadIntents");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.User", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("FirstName")
+                        .HasMaxLength(48)
+                        .HasColumnType("character varying(48)");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(48)
+                        .HasColumnType("character varying(48)");
+
+                    b.Property<string>("NormalizedName")
+                        .IsRequired()
+                        .HasMaxLength(48)
+                        .HasColumnType("character varying(48)");
+
+                    b.Property<string>("ProfilePictureUrl")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<string>("SecondName")
+                        .HasMaxLength(48)
+                        .HasColumnType("character varying(48)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("User");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.UserHasTrack", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("TrackId")
+                        .HasColumnType("uuid");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TrackId");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("UserHasTrack");
+                });
+
+            modelBuilder.Entity("Musify.Infrastructure.MassTransit.Sagas.TrackProcessingState", b =>
+                {
+                    b.Property<Guid>("CorrelationId")
+                        .HasColumnType("uuid");
+
+                    b.Property<bool>("AudioProcessed")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("CurrentState")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<bool>("PictureProcessed")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("CorrelationId");
+
+                    b.ToTable("TrackProcessingState");
+                });
+
+            modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.OutboxMessage", b =>
+                {
+                    b.HasOne("MassTransit.EntityFrameworkCoreIntegration.OutboxState", null)
+                        .WithMany()
+                        .HasForeignKey("OutboxId");
+
+                    b.HasOne("MassTransit.EntityFrameworkCoreIntegration.InboxState", null)
+                        .WithMany()
+                        .HasForeignKey("InboxMessageId", "InboxConsumerId")
+                        .HasPrincipalKey("MessageId", "ConsumerId");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.PlayList", b =>
+                {
+                    b.HasOne("Musify.Domain.Entities.User", "User")
+                        .WithMany("PlayLists")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.PlayListHasTrack", b =>
+                {
+                    b.HasOne("Musify.Domain.Entities.PlayList", "PlayList")
+                        .WithMany("PlayListTracks")
+                        .HasForeignKey("PlayListId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Musify.Domain.Entities.Track", "Track")
+                        .WithMany("PlayListTracks")
+                        .HasForeignKey("TrackId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("PlayList");
+
+                    b.Navigation("Track");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.UploadIntent", b =>
+                {
+                    b.HasOne("Musify.Domain.Entities.User", "User")
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.UserHasTrack", b =>
+                {
+                    b.HasOne("Musify.Domain.Entities.Track", "Track")
+                        .WithMany("UserTracks")
+                        .HasForeignKey("TrackId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Musify.Domain.Entities.User", "User")
+                        .WithMany("UserTracks")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Track");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.PlayList", b =>
+                {
+                    b.Navigation("PlayListTracks");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.Track", b =>
+                {
+                    b.Navigation("PlayListTracks");
+
+                    b.Navigation("UserTracks");
+                });
+
+            modelBuilder.Entity("Musify.Domain.Entities.User", b =>
+                {
+                    b.Navigation("PlayLists");
+
+                    b.Navigation("UserTracks");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/Musify.Infrastructure/Persistence/Migrations/20260705123932_AddTrackProcessingStateSaga.cs

@@ -0,0 +1,38 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Musify.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddTrackProcessingStateSaga : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "TrackProcessingState",
+                columns: table => new
+                {
+                    CorrelationId = table.Column<Guid>(type: "uuid", nullable: false),
+                    CurrentState = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: false),
+                    PictureProcessed = table.Column<bool>(type: "boolean", nullable: false),
+                    AudioProcessed = table.Column<bool>(type: "boolean", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_TrackProcessingState", x => x.CorrelationId);
+                });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "TrackProcessingState");
+        }
+    }
+}

backend/Musify.Infrastructure/Persistence/Migrations/DatabaseModelSnapshot.cs

@@ -484,6 +484,33 @@ namespace Musify.Infrastructure.Persistence.Migrations
                     b.ToTable("UserHasTrack");
                 });
 
+            modelBuilder.Entity("Musify.Infrastructure.MassTransit.Sagas.TrackProcessingState", b =>
+                {
+                    b.Property<Guid>("CorrelationId")
+                        .HasColumnType("uuid");
+
+                    b.Property<bool>("AudioProcessed")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("CurrentState")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<bool>("PictureProcessed")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("CorrelationId");
+
+                    b.ToTable("TrackProcessingState");
+                });
+
             modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.OutboxMessage", b =>
                 {
                     b.HasOne("MassTransit.EntityFrameworkCoreIntegration.OutboxState", null)