diff --git a/backend/Tests/Musify.Api.Tests/Authentication/CurrentUserTests.cs b/backend/Tests/Musify.Api.Tests/Authentication/CurrentUserTests.cs
index 981dda9..aecba63 100644
--- a/backend/Tests/Musify.Api.Tests/Authentication/CurrentUserTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Authentication/CurrentUserTests.cs
@@ -3,82 +3,83 @@ using Microsoft.AspNetCore.Http;
 using Musify.Api.Authentication;
 using Xunit;
 
-namespace Musify.Api.Tests.Authentication;
-
-public sealed class CurrentUserTests
+namespace Musify.Api.Tests.Authentication
 {
-    private static async Task<CurrentUser> BindAsync(ClaimsPrincipal principal)
+    public sealed class CurrentUserTests
     {
-        var context = new DefaultHttpContext { User = principal };
-        var bound = await CurrentUser.BindAsync(context, parameter: null!);
-        return bound!;
-    }
+        private static async Task<CurrentUser> BindAsync(ClaimsPrincipal principal)
+        {
+            var context = new DefaultHttpContext { User = principal };
+            var bound = await CurrentUser.BindAsync(context, parameter: null!);
+            return bound!;
+        }
 
-    private static ClaimsPrincipal AuthenticatedPrincipal(params Claim[] claims) =>
-        new(new ClaimsIdentity(claims, authenticationType: "TestAuth"));
+        private static ClaimsPrincipal AuthenticatedPrincipal(params Claim[] claims) =>
+            new(new ClaimsIdentity(claims, authenticationType: "TestAuth"));
 
-    [Fact]
-    public async Task BindAsync_AuthenticatedPrincipalWithValidClaims_PopulatesEveryField()
-    {
-        var principal = AuthenticatedPrincipal(
-            new Claim(ClaimTypes.NameIdentifier, "42"),
-            new Claim(ClaimTypes.Name, "jdoe"),
-            new Claim(ClaimTypes.GivenName, "Jane"),
-            new Claim(ClaimTypes.Surname, "Doe"));
+        [Fact]
+        public async Task BindAsync_AuthenticatedPrincipalWithValidClaims_PopulatesEveryField()
+        {
+            var principal = AuthenticatedPrincipal(
+                new Claim(ClaimTypes.NameIdentifier, "42"),
+                new Claim(ClaimTypes.Name, "jdoe"),
+                new Claim(ClaimTypes.GivenName, "Jane"),
+                new Claim(ClaimTypes.Surname, "Doe"));
 
-        var user = await BindAsync(principal);
+            var user = await BindAsync(principal);
 
-        Assert.True(user.IsAuthenticated);
-        Assert.Equal(42, user.Id);
-        Assert.Equal(42, user.RequiredId);
-        Assert.Equal("jdoe", user.Username);
-        Assert.Equal("Jane", user.FirstName);
-        Assert.Equal("Doe", user.LastName);
-    }
+            Assert.True(user.IsAuthenticated);
+            Assert.Equal(42, user.Id);
+            Assert.Equal(42, user.RequiredId);
+            Assert.Equal("jdoe", user.Username);
+            Assert.Equal("Jane", user.FirstName);
+            Assert.Equal("Doe", user.LastName);
+        }
 
-    [Fact]
-    public async Task BindAsync_AnonymousPrincipal_IsNotAuthenticatedAndHasNoId()
-    {
-        var user = await BindAsync(new ClaimsPrincipal(new ClaimsIdentity()));
+        [Fact]
+        public async Task BindAsync_AnonymousPrincipal_IsNotAuthenticatedAndHasNoId()
+        {
+            var user = await BindAsync(new ClaimsPrincipal(new ClaimsIdentity()));
 
-        Assert.False(user.IsAuthenticated);
-        Assert.Null(user.Id);
-    }
+            Assert.False(user.IsAuthenticated);
+            Assert.Null(user.Id);
+        }
 
-    [Theory]
-    [InlineData("not-a-number")]
-    [InlineData("0")]
-    [InlineData("")]
-    public async Task BindAsync_NonNumericOrZeroNameIdentifier_LeavesIdNull(string rawId)
-    {
-        var user = await BindAsync(AuthenticatedPrincipal(new Claim(ClaimTypes.NameIdentifier, rawId)));
+        [Theory]
+        [InlineData("not-a-number")]
+        [InlineData("0")]
+        [InlineData("")]
+        public async Task BindAsync_NonNumericOrZeroNameIdentifier_LeavesIdNull(string rawId)
+        {
+            var user = await BindAsync(AuthenticatedPrincipal(new Claim(ClaimTypes.NameIdentifier, rawId)));
 
-        Assert.Null(user.Id);
-    }
+            Assert.Null(user.Id);
+        }
 
-    [Fact]
-    public async Task RequiredId_MissingId_Throws()
-    {
-        var user = await BindAsync(new ClaimsPrincipal(new ClaimsIdentity()));
+        [Fact]
+        public async Task RequiredId_MissingId_Throws()
+        {
+            var user = await BindAsync(new ClaimsPrincipal(new ClaimsIdentity()));
 
-        Assert.Throws<InvalidOperationException>(() => user.RequiredId);
-    }
+            Assert.Throws<InvalidOperationException>(() => user.RequiredId);
+        }
 
-    [Fact]
-    public async Task HasClaim_ExistingClaimType_ReturnsTrue()
-    {
-        var user = await BindAsync(AuthenticatedPrincipal(new Claim("role", "admin")));
+        [Fact]
+        public async Task HasClaim_ExistingClaimType_ReturnsTrue()
+        {
+            var user = await BindAsync(AuthenticatedPrincipal(new Claim("role", "admin")));
 
-        Assert.True(user.HasClaim("role"));
-        Assert.False(user.HasClaim("missing"));
-    }
+            Assert.True(user.HasClaim("role"));
+            Assert.False(user.HasClaim("missing"));
+        }
 
-    [Fact]
-    public async Task FindClaim_ExistingClaimType_ReturnsItsValue()
-    {
-        var user = await BindAsync(AuthenticatedPrincipal(new Claim("picture", "https://avatar.example/jane.png")));
+        [Fact]
+        public async Task FindClaim_ExistingClaimType_ReturnsItsValue()
+        {
+            var user = await BindAsync(AuthenticatedPrincipal(new Claim("picture", "https://avatar.example/jane.png")));
 
-        Assert.Equal("https://avatar.example/jane.png", user.FindClaim("picture"));
-        Assert.Null(user.FindClaim("missing"));
+            Assert.Equal("https://avatar.example/jane.png", user.FindClaim("picture"));
+            Assert.Null(user.FindClaim("missing"));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Endpoints/AlbumEndpointsTests.cs b/backend/Tests/Musify.Api.Tests/Endpoints/AlbumEndpointsTests.cs
index 1fffda6..f5485cc 100644
--- a/backend/Tests/Musify.Api.Tests/Endpoints/AlbumEndpointsTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Endpoints/AlbumEndpointsTests.cs
@@ -6,93 +6,94 @@ using Musify.Api.Tests.TestSupport;
 using Musify.Application.Albums.Responses;
 using Xunit;
 
-namespace Musify.Api.Tests.Endpoints;
-
-[Collection(ApiCollection.Name)]
-public sealed class AlbumEndpointsTests(ApiTestFixture fixture)
+namespace Musify.Api.Tests.Endpoints
 {
-    private async Task<long> CreateUserAsync()
+    [Collection(ApiCollection.Name)]
+    public sealed class AlbumEndpointsTests(ApiTestFixture fixture)
     {
-        var userId = Random.Shared.NextInt64(1, long.MaxValue);
-        var response = await fixture.CreateAnonymousClient()
-            .PostAsJsonAsync("/users", new CreateUserRequest(userId, $"user-{userId}", null, null));
-        response.EnsureSuccessStatusCode();
-        return userId;
-    }
+        private async Task<long> CreateUserAsync()
+        {
+            var userId = Random.Shared.NextInt64(1, long.MaxValue);
+            var response = await fixture.CreateAnonymousClient()
+                .PostAsJsonAsync("/users", new CreateUserRequest(userId, $"user-{userId}", null, null));
+            response.EnsureSuccessStatusCode();
+            return userId;
+        }
 
-    [Fact]
-    public async Task PostAlbums_NoAuthHeader_ReturnsUnauthorized()
-    {
-        var response = await fixture.CreateAnonymousClient()
-            .PostAsJsonAsync("/albums", new CreateAlbumRequest("Unauthorized Album", null, null), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task PostAlbums_NoAuthHeader_ReturnsUnauthorized()
+        {
+            var response = await fixture.CreateAnonymousClient()
+                .PostAsJsonAsync("/albums", new CreateAlbumRequest("Unauthorized Album", null, null), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task PostAlbums_AuthenticatedExistingUser_ReturnsCreatedAlbum()
-    {
-        var userId = await CreateUserAsync();
-        var client = fixture.CreateAuthenticatedClient(userId);
+        [Fact]
+        public async Task PostAlbums_AuthenticatedExistingUser_ReturnsCreatedAlbum()
+        {
+            var userId = await CreateUserAsync();
+            var client = fixture.CreateAuthenticatedClient(userId);
 
-        var response = await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("My Album", "desc", 2024), TestContext.Current.CancellationToken);
+            var response = await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("My Album", "desc", 2024), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.Created, response.StatusCode);
-        var body = await response.Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
-        Assert.NotNull(body);
-        Assert.Equal("My Album", body.Title);
-        Assert.Equal(userId, body.OwnerUserId);
-    }
+            Assert.Equal(HttpStatusCode.Created, response.StatusCode);
+            var body = await response.Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+            Assert.NotNull(body);
+            Assert.Equal("My Album", body.Title);
+            Assert.Equal(userId, body.OwnerUserId);
+        }
 
-    [Fact]
-    public async Task PostAlbums_BlankTitle_ReturnsValidationProblem()
-    {
-        var userId = await CreateUserAsync();
-        var client = fixture.CreateAuthenticatedClient(userId);
+        [Fact]
+        public async Task PostAlbums_BlankTitle_ReturnsValidationProblem()
+        {
+            var userId = await CreateUserAsync();
+            var client = fixture.CreateAuthenticatedClient(userId);
 
-        var response = await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("", null, null), TestContext.Current.CancellationToken);
+            var response = await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("", null, null), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task GetAlbumById_AfterCreate_ReturnsIt()
-    {
-        var userId = await CreateUserAsync();
-        var client = fixture.CreateAuthenticatedClient(userId);
-        var created = await (await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("Findable", null, null), TestContext.Current.CancellationToken))
-            .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task GetAlbumById_AfterCreate_ReturnsIt()
+        {
+            var userId = await CreateUserAsync();
+            var client = fixture.CreateAuthenticatedClient(userId);
+            var created = await (await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("Findable", null, null), TestContext.Current.CancellationToken))
+                .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
 
-        var response = await fixture.CreateAnonymousClient().GetAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
+            var response = await fixture.CreateAnonymousClient().GetAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task DeleteAlbum_NotTheOwner_ReturnsUnauthorized()
-    {
-        var owner = await CreateUserAsync();
-        var stranger = await CreateUserAsync();
-        var created = await (await fixture.CreateAuthenticatedClient(owner).PostAsJsonAsync("/albums", new CreateAlbumRequest("Owned", null, null), TestContext.Current.CancellationToken))
-            .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task DeleteAlbum_NotTheOwner_ReturnsUnauthorized()
+        {
+            var owner = await CreateUserAsync();
+            var stranger = await CreateUserAsync();
+            var created = await (await fixture.CreateAuthenticatedClient(owner).PostAsJsonAsync("/albums", new CreateAlbumRequest("Owned", null, null), TestContext.Current.CancellationToken))
+                .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
 
-        var response = await fixture.CreateAuthenticatedClient(stranger).DeleteAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
+            var response = await fixture.CreateAuthenticatedClient(stranger).DeleteAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task DeleteAlbum_Owner_ReturnsNoContentAndAlbumIsGone()
-    {
-        var userId = await CreateUserAsync();
-        var client = fixture.CreateAuthenticatedClient(userId);
-        var created = await (await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("Deletable", null, null), TestContext.Current.CancellationToken))
-            .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task DeleteAlbum_Owner_ReturnsNoContentAndAlbumIsGone()
+        {
+            var userId = await CreateUserAsync();
+            var client = fixture.CreateAuthenticatedClient(userId);
+            var created = await (await client.PostAsJsonAsync("/albums", new CreateAlbumRequest("Deletable", null, null), TestContext.Current.CancellationToken))
+                .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
 
-        var deleteResponse = await client.DeleteAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
-        var getResponse = await fixture.CreateAnonymousClient().GetAsync($"/albums/{created.Id}", TestContext.Current.CancellationToken);
+            var deleteResponse = await client.DeleteAsync($"/albums/{created!.Id}", TestContext.Current.CancellationToken);
+            var getResponse = await fixture.CreateAnonymousClient().GetAsync($"/albums/{created.Id}", TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.NoContent, deleteResponse.StatusCode);
-        Assert.Equal(HttpStatusCode.NotFound, getResponse.StatusCode);
+            Assert.Equal(HttpStatusCode.NoContent, deleteResponse.StatusCode);
+            Assert.Equal(HttpStatusCode.NotFound, getResponse.StatusCode);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Endpoints/UserEndpointsTests.cs b/backend/Tests/Musify.Api.Tests/Endpoints/UserEndpointsTests.cs
index 64d5d2e..a7e0fc3 100644
--- a/backend/Tests/Musify.Api.Tests/Endpoints/UserEndpointsTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Endpoints/UserEndpointsTests.cs
@@ -5,69 +5,70 @@ using Musify.Api.Tests.TestSupport;
 using Musify.Application.Users.Responses;
 using Xunit;
 
-namespace Musify.Api.Tests.Endpoints;
-
-[Collection(ApiCollection.Name)]
-public sealed class UserEndpointsTests(ApiTestFixture fixture)
+namespace Musify.Api.Tests.Endpoints
 {
-    [Fact]
-    public async Task PostUsers_NewUser_ReturnsCreatedWithLocationHeader()
+    [Collection(ApiCollection.Name)]
+    public sealed class UserEndpointsTests(ApiTestFixture fixture)
     {
-        var client = fixture.CreateAnonymousClient();
-        var userId = Random.Shared.NextInt64(1, long.MaxValue);
+        [Fact]
+        public async Task PostUsers_NewUser_ReturnsCreatedWithLocationHeader()
+        {
+            var client = fixture.CreateAnonymousClient();
+            var userId = Random.Shared.NextInt64(1, long.MaxValue);
 
-        var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Jane Doe", "Jane", "Doe"), TestContext.Current.CancellationToken);
+            var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Jane Doe", "Jane", "Doe"), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.Created, response.StatusCode);
-        Assert.Equal($"/users/{userId}", response.Headers.Location?.OriginalString);
-        var body = await response.Content.ReadFromJsonAsync<UserApplicationResponse>(TestContext.Current.CancellationToken);
-        Assert.NotNull(body);
-        Assert.Equal("Jane Doe", body.Name);
-    }
+            Assert.Equal(HttpStatusCode.Created, response.StatusCode);
+            Assert.Equal($"/users/{userId}", response.Headers.Location?.OriginalString);
+            var body = await response.Content.ReadFromJsonAsync<UserApplicationResponse>(TestContext.Current.CancellationToken);
+            Assert.NotNull(body);
+            Assert.Equal("Jane Doe", body.Name);
+        }
 
-    [Fact]
-    public async Task PostUsers_BlankName_ReturnsValidationProblem()
-    {
-        var client = fixture.CreateAnonymousClient();
+        [Fact]
+        public async Task PostUsers_BlankName_ReturnsValidationProblem()
+        {
+            var client = fixture.CreateAnonymousClient();
 
-        var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(Random.Shared.NextInt64(1, long.MaxValue), "", null, null), TestContext.Current.CancellationToken);
+            var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(Random.Shared.NextInt64(1, long.MaxValue), "", null, null), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task PostUsers_DuplicateId_ReturnsConflict()
-    {
-        var client = fixture.CreateAnonymousClient();
-        var userId = Random.Shared.NextInt64(1, long.MaxValue);
-        await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "First", null, null), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task PostUsers_DuplicateId_ReturnsConflict()
+        {
+            var client = fixture.CreateAnonymousClient();
+            var userId = Random.Shared.NextInt64(1, long.MaxValue);
+            await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "First", null, null), TestContext.Current.CancellationToken);
 
-        var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Second", null, null), TestContext.Current.CancellationToken);
+            var response = await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Second", null, null), TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.Conflict, response.StatusCode);
-    }
+            Assert.Equal(HttpStatusCode.Conflict, response.StatusCode);
+        }
 
-    [Fact]
-    public async Task GetUserById_ExistingUser_ReturnsIt()
-    {
-        var client = fixture.CreateAnonymousClient();
-        var userId = Random.Shared.NextInt64(1, long.MaxValue);
-        await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Findable User", null, null), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task GetUserById_ExistingUser_ReturnsIt()
+        {
+            var client = fixture.CreateAnonymousClient();
+            var userId = Random.Shared.NextInt64(1, long.MaxValue);
+            await client.PostAsJsonAsync("/users", new CreateUserRequest(userId, "Findable User", null, null), TestContext.Current.CancellationToken);
 
-        var response = await client.GetAsync($"/users/{userId}", TestContext.Current.CancellationToken);
+            var response = await client.GetAsync($"/users/{userId}", TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
-        var body = await response.Content.ReadFromJsonAsync<UserApplicationResponse>(TestContext.Current.CancellationToken);
-        Assert.Equal("Findable User", body?.Name);
-    }
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            var body = await response.Content.ReadFromJsonAsync<UserApplicationResponse>(TestContext.Current.CancellationToken);
+            Assert.Equal("Findable User", body?.Name);
+        }
 
-    [Fact]
-    public async Task GetUserById_MissingUser_ReturnsNotFound()
-    {
-        var client = fixture.CreateAnonymousClient();
+        [Fact]
+        public async Task GetUserById_MissingUser_ReturnsNotFound()
+        {
+            var client = fixture.CreateAnonymousClient();
 
-        var response = await client.GetAsync($"/users/{Random.Shared.NextInt64(1, long.MaxValue)}", TestContext.Current.CancellationToken);
+            var response = await client.GetAsync($"/users/{Random.Shared.NextInt64(1, long.MaxValue)}", TestContext.Current.CancellationToken);
 
-        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+            Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Extensions/ErrorOrHttpExtensionsTests.cs b/backend/Tests/Musify.Api.Tests/Extensions/ErrorOrHttpExtensionsTests.cs
index 90b884e..86a7c4e 100644
--- a/backend/Tests/Musify.Api.Tests/Extensions/ErrorOrHttpExtensionsTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Extensions/ErrorOrHttpExtensionsTests.cs
@@ -4,134 +4,135 @@ using Microsoft.Extensions.DependencyInjection;
 using Musify.Api.Extensions;
 using Xunit;
 
-namespace Musify.Api.Tests.Extensions;
-
-public sealed class ErrorOrHttpExtensionsTests
+namespace Musify.Api.Tests.Extensions
 {
-    // The concrete IResult types (NoContent, UnauthorizedHttpResult, ...) resolve logging/problem-
-    // details services from HttpContext.RequestServices when they execute, so it can't be empty.
-    private static readonly IServiceProvider Services = new ServiceCollection().AddLogging().AddProblemDetails().BuildServiceProvider();
-
-    private static async Task<(int StatusCode, string Body)> ExecuteAsync(IResult result)
+    public sealed class ErrorOrHttpExtensionsTests
     {
-        var context = new DefaultHttpContext { RequestServices = Services };
-        var bodyStream = new MemoryStream();
-        context.Response.Body = bodyStream;
+        // The concrete IResult types (NoContent, UnauthorizedHttpResult, ...) resolve logging/problem-
+        // details services from HttpContext.RequestServices when they execute, so it can't be empty.
+        private static readonly IServiceProvider Services = new ServiceCollection().AddLogging().AddProblemDetails().BuildServiceProvider();
 
-        await result.ExecuteAsync(context);
-
-        bodyStream.Position = 0;
-        using var reader = new StreamReader(bodyStream);
-        return (context.Response.StatusCode, await reader.ReadToEndAsync());
-    }
-
-    [Fact]
-    public async Task ToHttpResult_Success_ReturnsNoContent()
-    {
-        ErrorOr<Success> result = new Success();
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status204NoContent, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_Value_ReturnsOkWithTheValue()
-    {
-        ErrorOr<string> result = "hello";
-
-        var (statusCode, body) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status200OK, statusCode);
-        Assert.Contains("hello", body);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_NotFoundError_ReturnsNotFound()
-    {
-        ErrorOr<string> result = Error.NotFound(description: "not here");
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status404NotFound, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_UnauthorizedError_ReturnsUnauthorized()
-    {
-        ErrorOr<string> result = Error.Unauthorized();
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status401Unauthorized, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_ForbiddenError_ReturnsForbidden()
-    {
-        ErrorOr<string> result = Error.Forbidden();
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status403Forbidden, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_ConflictError_ReturnsConflict()
-    {
-        ErrorOr<string> result = Error.Conflict();
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status409Conflict, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_FailureError_ReturnsProblem500()
-    {
-        ErrorOr<string> result = Error.Failure();
-
-        var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
-
-        Assert.Equal(StatusCodes.Status500InternalServerError, statusCode);
-    }
-
-    [Fact]
-    public async Task ToHttpResult_ValidationErrors_ReturnsValidationProblem()
-    {
-        ErrorOr<string> result = new List<Error>
+        private static async Task<(int StatusCode, string Body)> ExecuteAsync(IResult result)
         {
-            Error.Validation("Name", "Name is required"),
-            Error.Validation("Name", "Name is too long"),
-            Error.Validation("Age", "Age must be positive"),
-        };
+            var context = new DefaultHttpContext { RequestServices = Services };
+            var bodyStream = new MemoryStream();
+            context.Response.Body = bodyStream;
 
-        var (statusCode, body) = await ExecuteAsync(result.ToHttpResult());
+            await result.ExecuteAsync(context);
 
-        Assert.Equal(StatusCodes.Status400BadRequest, statusCode);
-        Assert.Contains("Name is required", body);
-        Assert.Contains("Age must be positive", body);
-    }
+            bodyStream.Position = 0;
+            using var reader = new StreamReader(bodyStream);
+            return (context.Response.StatusCode, await reader.ReadToEndAsync());
+        }
 
-    [Fact]
-    public async Task ToCreatedResult_Success_ReturnsCreatedAtTheGivenLocation()
-    {
-        ErrorOr<string> result = "the-id";
+        [Fact]
+        public async Task ToHttpResult_Success_ReturnsNoContent()
+        {
+            ErrorOr<Success> result = new Success();
 
-        var context = new DefaultHttpContext { RequestServices = Services, Response = { Body = new MemoryStream() } };
-        await result.ToCreatedResult(value => $"/things/{value}").ExecuteAsync(context);
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
 
-        Assert.Equal(StatusCodes.Status201Created, context.Response.StatusCode);
-        Assert.Equal("/things/the-id", context.Response.Headers.Location);
-    }
+            Assert.Equal(StatusCodes.Status204NoContent, statusCode);
+        }
 
-    [Fact]
-    public async Task ToCreatedResult_Error_ReturnsTheMappedErrorStatus()
-    {
-        ErrorOr<string> result = Error.Conflict();
+        [Fact]
+        public async Task ToHttpResult_Value_ReturnsOkWithTheValue()
+        {
+            ErrorOr<string> result = "hello";
 
-        var (statusCode, _) = await ExecuteAsync(result.ToCreatedResult(value => $"/things/{value}"));
+            var (statusCode, body) = await ExecuteAsync(result.ToHttpResult());
 
-        Assert.Equal(StatusCodes.Status409Conflict, statusCode);
+            Assert.Equal(StatusCodes.Status200OK, statusCode);
+            Assert.Contains("hello", body);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_NotFoundError_ReturnsNotFound()
+        {
+            ErrorOr<string> result = Error.NotFound(description: "not here");
+
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status404NotFound, statusCode);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_UnauthorizedError_ReturnsUnauthorized()
+        {
+            ErrorOr<string> result = Error.Unauthorized();
+
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status401Unauthorized, statusCode);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_ForbiddenError_ReturnsForbidden()
+        {
+            ErrorOr<string> result = Error.Forbidden();
+
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status403Forbidden, statusCode);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_ConflictError_ReturnsConflict()
+        {
+            ErrorOr<string> result = Error.Conflict();
+
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status409Conflict, statusCode);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_FailureError_ReturnsProblem500()
+        {
+            ErrorOr<string> result = Error.Failure();
+
+            var (statusCode, _) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status500InternalServerError, statusCode);
+        }
+
+        [Fact]
+        public async Task ToHttpResult_ValidationErrors_ReturnsValidationProblem()
+        {
+            ErrorOr<string> result = new List<Error>
+            {
+                Error.Validation("Name", "Name is required"),
+                Error.Validation("Name", "Name is too long"),
+                Error.Validation("Age", "Age must be positive"),
+            };
+
+            var (statusCode, body) = await ExecuteAsync(result.ToHttpResult());
+
+            Assert.Equal(StatusCodes.Status400BadRequest, statusCode);
+            Assert.Contains("Name is required", body);
+            Assert.Contains("Age must be positive", body);
+        }
+
+        [Fact]
+        public async Task ToCreatedResult_Success_ReturnsCreatedAtTheGivenLocation()
+        {
+            ErrorOr<string> result = "the-id";
+
+            var context = new DefaultHttpContext { RequestServices = Services, Response = { Body = new MemoryStream() } };
+            await result.ToCreatedResult(value => $"/things/{value}").ExecuteAsync(context);
+
+            Assert.Equal(StatusCodes.Status201Created, context.Response.StatusCode);
+            Assert.Equal("/things/the-id", context.Response.Headers.Location);
+        }
+
+        [Fact]
+        public async Task ToCreatedResult_Error_ReturnsTheMappedErrorStatus()
+        {
+            ErrorOr<string> result = Error.Conflict();
+
+            var (statusCode, _) = await ExecuteAsync(result.ToCreatedResult(value => $"/things/{value}"));
+
+            Assert.Equal(StatusCodes.Status409Conflict, statusCode);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Filters/ValidationFilterTests.cs b/backend/Tests/Musify.Api.Tests/Filters/ValidationFilterTests.cs
index cf0bf9b..32fbe2f 100644
--- a/backend/Tests/Musify.Api.Tests/Filters/ValidationFilterTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Filters/ValidationFilterTests.cs
@@ -6,61 +6,62 @@ using Musify.Api.Filters;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Api.Tests.Filters;
-
-public sealed class ValidationFilterTests
+namespace Musify.Api.Tests.Filters
 {
-    public sealed record Payload(string Name);
-
-    // EndpointFilterInvocationContext.Create has no (HttpContext, object[]) overload — only
-    // Create<T0>, Create<T0,T1>, etc. Passing an object[] to a params-object[] call site binds
-    // to Create<T0> with T0 inferred as object[] itself, so .Arguments ends up with one element
-    // (the array, boxed) instead of the array's contents — OfType<Payload>() then never matches
-    // and the filter silently falls through to "no argument, skip validation" for every case.
-    private static EndpointFilterInvocationContext CreateContext<T>(T argument) =>
-        EndpointFilterInvocationContext.Create(new DefaultHttpContext(), argument);
-
-    [Fact]
-    public async Task InvokeAsync_ValidPayload_CallsNext()
+    public sealed class ValidationFilterTests
     {
-        var validator = Substitute.For<IValidator<Payload>>();
-        validator.ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>()).Returns(new ValidationResult());
-        var filter = new ValidationFilter<Payload>(validator);
-        var context = CreateContext(new Payload("ok"));
+        public sealed record Payload(string Name);
 
-        var result = await filter.InvokeAsync(context, _ => ValueTask.FromResult<object?>("next-called"));
+        // EndpointFilterInvocationContext.Create has no (HttpContext, object[]) overload — only
+        // Create<T0>, Create<T0,T1>, etc. Passing an object[] to a params-object[] call site binds
+        // to Create<T0> with T0 inferred as object[] itself, so .Arguments ends up with one element
+        // (the array, boxed) instead of the array's contents — OfType<Payload>() then never matches
+        // and the filter silently falls through to "no argument, skip validation" for every case.
+        private static EndpointFilterInvocationContext CreateContext<T>(T argument) =>
+            EndpointFilterInvocationContext.Create(new DefaultHttpContext(), argument);
 
-        Assert.Equal("next-called", result);
-        await validator.Received(1).ValidateAsync(Arg.Is<Payload>(p => p.Name == "ok"), Arg.Any<CancellationToken>());
-    }
+        [Fact]
+        public async Task InvokeAsync_ValidPayload_CallsNext()
+        {
+            var validator = Substitute.For<IValidator<Payload>>();
+            validator.ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>()).Returns(new ValidationResult());
+            var filter = new ValidationFilter<Payload>(validator);
+            var context = CreateContext(new Payload("ok"));
 
-    [Fact]
-    public async Task InvokeAsync_InvalidPayload_ReturnsValidationProblemWithoutCallingNext()
-    {
-        var validator = Substitute.For<IValidator<Payload>>();
-        validator.ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>())
-            .Returns(new ValidationResult([new ValidationFailure("Name", "Name is required")]));
-        var filter = new ValidationFilter<Payload>(validator);
-        var context = CreateContext(new Payload(""));
-        var nextCalled = false;
+            var result = await filter.InvokeAsync(context, _ => ValueTask.FromResult<object?>("next-called"));
 
-        var result = await filter.InvokeAsync(context, _ => { nextCalled = true; return ValueTask.FromResult<object?>(null); });
+            Assert.Equal("next-called", result);
+            await validator.Received(1).ValidateAsync(Arg.Is<Payload>(p => p.Name == "ok"), Arg.Any<CancellationToken>());
+        }
 
-        Assert.False(nextCalled);
-        var problem = Assert.IsType<ProblemHttpResult>(result);
-        Assert.Equal(StatusCodes.Status400BadRequest, problem.StatusCode);
-    }
+        [Fact]
+        public async Task InvokeAsync_InvalidPayload_ReturnsValidationProblemWithoutCallingNext()
+        {
+            var validator = Substitute.For<IValidator<Payload>>();
+            validator.ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>())
+                .Returns(new ValidationResult([new ValidationFailure("Name", "Name is required")]));
+            var filter = new ValidationFilter<Payload>(validator);
+            var context = CreateContext(new Payload(""));
+            var nextCalled = false;
 
-    [Fact]
-    public async Task InvokeAsync_NoMatchingArgument_CallsNextWithoutValidating()
-    {
-        var validator = Substitute.For<IValidator<Payload>>();
-        var filter = new ValidationFilter<Payload>(validator);
-        var context = CreateContext(42);
+            var result = await filter.InvokeAsync(context, _ => { nextCalled = true; return ValueTask.FromResult<object?>(null); });
 
-        var result = await filter.InvokeAsync(context, _ => ValueTask.FromResult<object?>("next-called"));
+            Assert.False(nextCalled);
+            var problem = Assert.IsType<ProblemHttpResult>(result);
+            Assert.Equal(StatusCodes.Status400BadRequest, problem.StatusCode);
+        }
 
-        Assert.Equal("next-called", result);
-        await validator.DidNotReceiveWithAnyArgs().ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>());
+        [Fact]
+        public async Task InvokeAsync_NoMatchingArgument_CallsNextWithoutValidating()
+        {
+            var validator = Substitute.For<IValidator<Payload>>();
+            var filter = new ValidationFilter<Payload>(validator);
+            var context = CreateContext(42);
+
+            var result = await filter.InvokeAsync(context, _ => ValueTask.FromResult<object?>("next-called"));
+
+            Assert.Equal("next-called", result);
+            await validator.DidNotReceiveWithAnyArgs().ValidateAsync(Arg.Any<Payload>(), Arg.Any<CancellationToken>());
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/TestSupport/ApiTestFixture.cs b/backend/Tests/Musify.Api.Tests/TestSupport/ApiTestFixture.cs
index 7810496..0ed2877 100644
--- a/backend/Tests/Musify.Api.Tests/TestSupport/ApiTestFixture.cs
+++ b/backend/Tests/Musify.Api.Tests/TestSupport/ApiTestFixture.cs
@@ -11,111 +11,112 @@ using NSubstitute;
 using Testcontainers.PostgreSql;
 using Xunit;
 
-namespace Musify.Api.Tests.TestSupport;
-
-/// <summary>
-/// Boots the real <c>Musify.Api</c> host — real routing, real auth/authorization pipeline,
-/// real validators, real Mediator handlers — against a private Postgres container (so EF
-/// queries behave like production, not like a stand-in). The services this API talks to over
-/// the network (object storage, YouTube, the message bus, stream-ticket signing) are replaced
-/// with NSubstitute fakes: they are Infrastructure's job to verify against the real thing (see
-/// Musify.Infrastructure.Tests), not the HTTP layer's.
-/// </summary>
-public sealed class ApiTestFixture : WebApplicationFactory<Program>, IAsyncLifetime
+namespace Musify.Api.Tests.TestSupport
 {
-    private readonly PostgreSqlContainer postgres = new PostgreSqlBuilder("postgres:17-alpine")
-        .WithDatabase("musify_api_test")
-        .WithUsername("postgres")
-        .WithPassword("postgres")
-        .Build();
-
-    public IStorageService StorageService { get; } = Substitute.For<IStorageService>();
-
-    public IEventBus EventBus { get; } = Substitute.For<IEventBus>();
-
-    public IYouTubeMusicService YouTubeMusicService { get; } = Substitute.For<IYouTubeMusicService>();
-
-    public IStreamTicketService StreamTicketService { get; } = Substitute.For<IStreamTicketService>();
-
-    public async ValueTask InitializeAsync()
+    /// <summary>
+    /// Boots the real <c>Musify.Api</c> host — real routing, real auth/authorization pipeline,
+    /// real validators, real Mediator handlers — against a private Postgres container (so EF
+    /// queries behave like production, not like a stand-in). The services this API talks to over
+    /// the network (object storage, YouTube, the message bus, stream-ticket signing) are replaced
+    /// with NSubstitute fakes: they are Infrastructure's job to verify against the real thing (see
+    /// Musify.Infrastructure.Tests), not the HTTP layer's.
+    /// </summary>
+    public sealed class ApiTestFixture : WebApplicationFactory<Program>, IAsyncLifetime
     {
-        await postgres.StartAsync();
+        private readonly PostgreSqlContainer postgres = new PostgreSqlBuilder("postgres:17-alpine")
+            .WithDatabase("musify_api_test")
+            .WithUsername("postgres")
+            .WithPassword("postgres")
+            .Build();
 
-        using var scope = Services.CreateScope();
-        var database = scope.ServiceProvider.GetRequiredService<Musify.Infrastructure.Persistence.Database>();
-        await database.Database.MigrateAsync();
-    }
+        public IStorageService StorageService { get; } = Substitute.For<IStorageService>();
 
-    // xUnit v3's IAsyncLifetime IS System.IAsyncDisposable (rather than declaring its own
-    // Task-returning DisposeAsync as in v2), so there is a single DisposeAsync slot to fill —
-    // override the one WebApplicationFactory already provides instead of implementing the
-    // interface explicitly alongside it.
-    public override async ValueTask DisposeAsync()
-    {
-        await base.DisposeAsync();
-        await postgres.DisposeAsync();
-    }
+        public IEventBus EventBus { get; } = Substitute.For<IEventBus>();
 
-    /// <summary>An <see cref="HttpClient"/> with no auth header — every protected endpoint answers 401.</summary>
-    public HttpClient CreateAnonymousClient() => CreateClient();
+        public IYouTubeMusicService YouTubeMusicService { get; } = Substitute.For<IYouTubeMusicService>();
 
-    /// <summary>An <see cref="HttpClient"/> authenticated as the given user id (see <see cref="FakeAuthenticationHandler"/>).</summary>
-    public HttpClient CreateAuthenticatedClient(long userId, string userName = "test-user")
-    {
-        var client = CreateClient();
-        client.DefaultRequestHeaders.Add(FakeAuthenticationHandler.UserIdHeader, userId.ToString());
-        client.DefaultRequestHeaders.Add("X-Test-User-Name", userName);
-        return client;
-    }
+        public IStreamTicketService StreamTicketService { get; } = Substitute.For<IStreamTicketService>();
 
-    protected override void ConfigureWebHost(IWebHostBuilder builder)
-    {
-        builder.ConfigureAppConfiguration((_, configuration) =>
+        public async ValueTask InitializeAsync()
         {
-            configuration.AddInMemoryCollection(new Dictionary<string, string?>
+            await postgres.StartAsync();
+
+            using var scope = Services.CreateScope();
+            var database = scope.ServiceProvider.GetRequiredService<Musify.Infrastructure.Persistence.Database>();
+            await database.Database.MigrateAsync();
+        }
+
+        // xUnit v3's IAsyncLifetime IS System.IAsyncDisposable (rather than declaring its own
+        // Task-returning DisposeAsync as in v2), so there is a single DisposeAsync slot to fill —
+        // override the one WebApplicationFactory already provides instead of implementing the
+        // interface explicitly alongside it.
+        public override async ValueTask DisposeAsync()
+        {
+            await base.DisposeAsync();
+            await postgres.DisposeAsync();
+        }
+
+        /// <summary>An <see cref="HttpClient"/> with no auth header — every protected endpoint answers 401.</summary>
+        public HttpClient CreateAnonymousClient() => CreateClient();
+
+        /// <summary>An <see cref="HttpClient"/> authenticated as the given user id (see <see cref="FakeAuthenticationHandler"/>).</summary>
+        public HttpClient CreateAuthenticatedClient(long userId, string userName = "test-user")
+        {
+            var client = CreateClient();
+            client.DefaultRequestHeaders.Add(FakeAuthenticationHandler.UserIdHeader, userId.ToString());
+            client.DefaultRequestHeaders.Add("X-Test-User-Name", userName);
+            return client;
+        }
+
+        protected override void ConfigureWebHost(IWebHostBuilder builder)
+        {
+            builder.ConfigureAppConfiguration((_, configuration) =>
             {
-                ["Database:ConnectionString"] = postgres.GetConnectionString(),
-                ["Authentication:MetadataAddress"] = "https://auth.musify.test/.well-known/openid-configuration",
-                ["Authentication:IssuerAddress"] = "https://auth.musify.test",
-                ["Authentication:AudienceAddress"] = "musify-api-test",
-                ["Authentication:ClientId"] = "musify-api-test",
-                ["Authentication:AuthorizationEndpoint"] = "https://auth.musify.test/authorize",
-                ["Authentication:TokenEndpoint"] = "https://auth.musify.test/token",
-                ["Authentication:Scopes:0"] = "openid",
-                ["StreamTicket:PrivateKeyPath"] = "unused-in-tests.pem",
-                ["OpenTelemetry:OtlpEndpoint"] = "http://localhost:4317",
-                ["MassTransit:Address"] = "rabbitmq://localhost:5672",
-                ["MassTransit:Username"] = "guest",
-                ["MassTransit:Password"] = "guest",
-                ["InfrastructureStorage:Address"] = "http://localhost:8333",
-                ["InfrastructureStorage:AccessKey"] = "unused-in-tests",
-                ["InfrastructureStorage:SecretAccessKey"] = "unused-in-tests",
-                ["InfrastructureStorage:ForcePathStyle"] = "true",
-                ["InfrastructureStorage:UseHttp"] = "true",
-                ["ApplicationStorage:Bucket"] = "musify-api-test",
-                ["StreamGateway:PublicBaseUrl"] = "http://stream.musify.test",
-                ["PlayList:SeedPresetPictures"] = "false",
+                configuration.AddInMemoryCollection(new Dictionary<string, string?>
+                {
+                    ["Database:ConnectionString"] = postgres.GetConnectionString(),
+                    ["Authentication:MetadataAddress"] = "https://auth.musify.test/.well-known/openid-configuration",
+                    ["Authentication:IssuerAddress"] = "https://auth.musify.test",
+                    ["Authentication:AudienceAddress"] = "musify-api-test",
+                    ["Authentication:ClientId"] = "musify-api-test",
+                    ["Authentication:AuthorizationEndpoint"] = "https://auth.musify.test/authorize",
+                    ["Authentication:TokenEndpoint"] = "https://auth.musify.test/token",
+                    ["Authentication:Scopes:0"] = "openid",
+                    ["StreamTicket:PrivateKeyPath"] = "unused-in-tests.pem",
+                    ["OpenTelemetry:OtlpEndpoint"] = "http://localhost:4317",
+                    ["MassTransit:Address"] = "rabbitmq://localhost:5672",
+                    ["MassTransit:Username"] = "guest",
+                    ["MassTransit:Password"] = "guest",
+                    ["InfrastructureStorage:Address"] = "http://localhost:8333",
+                    ["InfrastructureStorage:AccessKey"] = "unused-in-tests",
+                    ["InfrastructureStorage:SecretAccessKey"] = "unused-in-tests",
+                    ["InfrastructureStorage:ForcePathStyle"] = "true",
+                    ["InfrastructureStorage:UseHttp"] = "true",
+                    ["ApplicationStorage:Bucket"] = "musify-api-test",
+                    ["StreamGateway:PublicBaseUrl"] = "http://stream.musify.test",
+                    ["PlayList:SeedPresetPictures"] = "false",
+                });
             });
-        });
 
-        builder.ConfigureTestServices(services =>
-        {
-            services.Replace(ServiceDescriptor.Singleton(StorageService));
-            services.Replace(ServiceDescriptor.Scoped(_ => EventBus));
-            services.Replace(ServiceDescriptor.Singleton(YouTubeMusicService));
-            services.Replace(ServiceDescriptor.Singleton(StreamTicketService));
+            builder.ConfigureTestServices(services =>
+            {
+                services.Replace(ServiceDescriptor.Singleton(StorageService));
+                services.Replace(ServiceDescriptor.Scoped(_ => EventBus));
+                services.Replace(ServiceDescriptor.Singleton(YouTubeMusicService));
+                services.Replace(ServiceDescriptor.Singleton(StreamTicketService));
 
-            // Overrides the real JwtBearer scheme as the default, so requests authenticate via
-            // FakeAuthenticationHandler instead of needing a real token and a reachable IdP.
-            services
-                .AddAuthentication(FakeAuthenticationHandler.SchemeName)
-                .AddScheme<AuthenticationSchemeOptions, FakeAuthenticationHandler>(FakeAuthenticationHandler.SchemeName, _ => { });
-        });
+                // Overrides the real JwtBearer scheme as the default, so requests authenticate via
+                // FakeAuthenticationHandler instead of needing a real token and a reachable IdP.
+                services
+                    .AddAuthentication(FakeAuthenticationHandler.SchemeName)
+                    .AddScheme<AuthenticationSchemeOptions, FakeAuthenticationHandler>(FakeAuthenticationHandler.SchemeName, _ => { });
+            });
+        }
+    }
+
+    [CollectionDefinition(Name)]
+    public sealed class ApiCollection : ICollectionFixture<ApiTestFixture>
+    {
+        public const string Name = "Api";
     }
 }
-
-[CollectionDefinition(Name)]
-public sealed class ApiCollection : ICollectionFixture<ApiTestFixture>
-{
-    public const string Name = "Api";
-}
diff --git a/backend/Tests/Musify.Api.Tests/TestSupport/FakeAuthenticationHandler.cs b/backend/Tests/Musify.Api.Tests/TestSupport/FakeAuthenticationHandler.cs
index 24f0231..d35009e 100644
--- a/backend/Tests/Musify.Api.Tests/TestSupport/FakeAuthenticationHandler.cs
+++ b/backend/Tests/Musify.Api.Tests/TestSupport/FakeAuthenticationHandler.cs
@@ -4,34 +4,35 @@ using Microsoft.AspNetCore.Authentication;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
-namespace Musify.Api.Tests.TestSupport;
-
-/// <summary>
-/// Replaces the real JwtBearer handler in the test host: a request carrying the
-/// <see cref="UserIdHeader"/> header authenticates as that user id, with no real token,
-/// issuer or JWKS endpoint involved. A request without the header stays anonymous, so
-/// endpoints under <c>.RequireAuthorization()</c> correctly answer 401.
-/// </summary>
-public sealed class FakeAuthenticationHandler(
-    IOptionsMonitor<AuthenticationSchemeOptions> options,
-    ILoggerFactory logger,
-    UrlEncoder encoder)
-    : AuthenticationHandler<AuthenticationSchemeOptions>(options, logger, encoder)
+namespace Musify.Api.Tests.TestSupport
 {
-    public const string SchemeName = "Test";
-    public const string UserIdHeader = "X-Test-User-Id";
-
-    protected override Task<AuthenticateResult> HandleAuthenticateAsync()
+    /// <summary>
+    /// Replaces the real JwtBearer handler in the test host: a request carrying the
+    /// <see cref="UserIdHeader"/> header authenticates as that user id, with no real token,
+    /// issuer or JWKS endpoint involved. A request without the header stays anonymous, so
+    /// endpoints under <c>.RequireAuthorization()</c> correctly answer 401.
+    /// </summary>
+    public sealed class FakeAuthenticationHandler(
+        IOptionsMonitor<AuthenticationSchemeOptions> options,
+        ILoggerFactory logger,
+        UrlEncoder encoder)
+        : AuthenticationHandler<AuthenticationSchemeOptions>(options, logger, encoder)
     {
-        if (!Request.Headers.TryGetValue(UserIdHeader, out var userId) || string.IsNullOrEmpty(userId))
-            return Task.FromResult(AuthenticateResult.NoResult());
+        public const string SchemeName = "Test";
+        public const string UserIdHeader = "X-Test-User-Id";
 
-        var claims = new List<Claim> { new(ClaimTypes.NameIdentifier, userId!) };
-        if (Request.Headers.TryGetValue("X-Test-User-Name", out var userName) && !string.IsNullOrEmpty(userName))
-            claims.Add(new Claim(ClaimTypes.Name, userName!));
+        protected override Task<AuthenticateResult> HandleAuthenticateAsync()
+        {
+            if (!Request.Headers.TryGetValue(UserIdHeader, out var userId) || string.IsNullOrEmpty(userId))
+                return Task.FromResult(AuthenticateResult.NoResult());
 
-        var identity = new ClaimsIdentity(claims, SchemeName);
-        var ticket = new AuthenticationTicket(new ClaimsPrincipal(identity), SchemeName);
-        return Task.FromResult(AuthenticateResult.Success(ticket));
+            var claims = new List<Claim> { new(ClaimTypes.NameIdentifier, userId!) };
+            if (Request.Headers.TryGetValue("X-Test-User-Name", out var userName) && !string.IsNullOrEmpty(userName))
+                claims.Add(new Claim(ClaimTypes.Name, userName!));
+
+            var identity = new ClaimsIdentity(claims, SchemeName);
+            var ticket = new AuthenticationTicket(new ClaimsPrincipal(identity), SchemeName);
+            return Task.FromResult(AuthenticateResult.Success(ticket));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Validators/CreateAlbumRequestValidatorTests.cs b/backend/Tests/Musify.Api.Tests/Validators/CreateAlbumRequestValidatorTests.cs
index 6cd9099..c7008ca 100644
--- a/backend/Tests/Musify.Api.Tests/Validators/CreateAlbumRequestValidatorTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Validators/CreateAlbumRequestValidatorTests.cs
@@ -2,74 +2,75 @@ using Musify.Api.DataTransferObjects.Albums;
 using Musify.Api.Validators.Albums;
 using Xunit;
 
-namespace Musify.Api.Tests.Validators;
-
-public sealed class CreateAlbumRequestValidatorTests
+namespace Musify.Api.Tests.Validators
 {
-    private readonly CreateAlbumRequestValidator validator = new();
-
-    [Fact]
-    public void Validate_ValidRequest_Passes()
+    public sealed class CreateAlbumRequestValidatorTests
     {
-        var result = validator.Validate(new CreateAlbumRequest("My Album", "A short description", 2024));
+        private readonly CreateAlbumRequestValidator validator = new();
 
-        Assert.True(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ValidRequest_Passes()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("My Album", "A short description", 2024));
 
-    [Fact]
-    public void Validate_ValidRequestWithoutOptionalFields_Passes()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("My Album", null, null));
+            Assert.True(result.IsValid);
+        }
 
-        Assert.True(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ValidRequestWithoutOptionalFields_Passes()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("My Album", null, null));
 
-    [Fact]
-    public void Validate_BlankTitle_Fails()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("", null, null));
+            Assert.True(result.IsValid);
+        }
 
-        Assert.False(result.IsValid);
-        Assert.Contains(result.Errors, e => e.PropertyName == nameof(CreateAlbumRequest.Title));
-    }
+        [Fact]
+        public void Validate_BlankTitle_Fails()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("", null, null));
 
-    [Fact]
-    public void Validate_TitleOverMaxLength_Fails()
-    {
-        var result = validator.Validate(new CreateAlbumRequest(new string('a', 201), null, null));
+            Assert.False(result.IsValid);
+            Assert.Contains(result.Errors, e => e.PropertyName == nameof(CreateAlbumRequest.Title));
+        }
 
-        Assert.False(result.IsValid);
-    }
+        [Fact]
+        public void Validate_TitleOverMaxLength_Fails()
+        {
+            var result = validator.Validate(new CreateAlbumRequest(new string('a', 201), null, null));
 
-    [Fact]
-    public void Validate_ReleaseYearBeforeTheEarliestBoundary_Fails()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Earliest - 1));
+            Assert.False(result.IsValid);
+        }
 
-        Assert.False(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ReleaseYearBeforeTheEarliestBoundary_Fails()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Earliest - 1));
 
-    [Fact]
-    public void Validate_ReleaseYearAtTheEarliestBoundary_Passes()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Earliest));
+            Assert.False(result.IsValid);
+        }
 
-        Assert.True(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ReleaseYearAtTheEarliestBoundary_Passes()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Earliest));
 
-    [Fact]
-    public void Validate_ReleaseYearAtTheLatestBoundary_Passes()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Latest));
+            Assert.True(result.IsValid);
+        }
 
-        Assert.True(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ReleaseYearAtTheLatestBoundary_Passes()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Latest));
 
-    [Fact]
-    public void Validate_ReleaseYearPastTheLatestBoundary_Fails()
-    {
-        var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Latest + 1));
+            Assert.True(result.IsValid);
+        }
 
-        Assert.False(result.IsValid);
+        [Fact]
+        public void Validate_ReleaseYearPastTheLatestBoundary_Fails()
+        {
+            var result = validator.Validate(new CreateAlbumRequest("Title", null, AlbumReleaseYear.Latest + 1));
+
+            Assert.False(result.IsValid);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Api.Tests/Validators/CreateUserRequestValidatorTests.cs b/backend/Tests/Musify.Api.Tests/Validators/CreateUserRequestValidatorTests.cs
index 36ccb0f..fffb0bf 100644
--- a/backend/Tests/Musify.Api.Tests/Validators/CreateUserRequestValidatorTests.cs
+++ b/backend/Tests/Musify.Api.Tests/Validators/CreateUserRequestValidatorTests.cs
@@ -2,50 +2,51 @@ using Musify.Api.DataTransferObjects.Users;
 using Musify.Api.Validators.Users;
 using Xunit;
 
-namespace Musify.Api.Tests.Validators;
-
-public sealed class CreateUserRequestValidatorTests
+namespace Musify.Api.Tests.Validators
 {
-    private readonly CreateUserRequestValidator validator = new();
-
-    [Fact]
-    public void Validate_ValidRequest_Passes()
+    public sealed class CreateUserRequestValidatorTests
     {
-        var result = validator.Validate(new CreateUserRequest(1, "Jane Doe", "Jane", "Doe"));
+        private readonly CreateUserRequestValidator validator = new();
 
-        Assert.True(result.IsValid);
-    }
+        [Fact]
+        public void Validate_ValidRequest_Passes()
+        {
+            var result = validator.Validate(new CreateUserRequest(1, "Jane Doe", "Jane", "Doe"));
 
-    [Fact]
-    public void Validate_ZeroId_Fails()
-    {
-        var result = validator.Validate(new CreateUserRequest(0, "Jane Doe", null, null));
+            Assert.True(result.IsValid);
+        }
 
-        Assert.False(result.IsValid);
-        Assert.Contains(result.Errors, e => e.PropertyName == nameof(CreateUserRequest.Id));
-    }
+        [Fact]
+        public void Validate_ZeroId_Fails()
+        {
+            var result = validator.Validate(new CreateUserRequest(0, "Jane Doe", null, null));
 
-    [Fact]
-    public void Validate_BlankName_Fails()
-    {
-        var result = validator.Validate(new CreateUserRequest(1, "", null, null));
+            Assert.False(result.IsValid);
+            Assert.Contains(result.Errors, e => e.PropertyName == nameof(CreateUserRequest.Id));
+        }
 
-        Assert.False(result.IsValid);
-    }
+        [Fact]
+        public void Validate_BlankName_Fails()
+        {
+            var result = validator.Validate(new CreateUserRequest(1, "", null, null));
 
-    [Fact]
-    public void Validate_NameOverMaxLength_Fails()
-    {
-        var result = validator.Validate(new CreateUserRequest(1, new string('a', 49), null, null));
+            Assert.False(result.IsValid);
+        }
 
-        Assert.False(result.IsValid);
-    }
+        [Fact]
+        public void Validate_NameOverMaxLength_Fails()
+        {
+            var result = validator.Validate(new CreateUserRequest(1, new string('a', 49), null, null));
 
-    [Fact]
-    public void Validate_OptionalNamesOmitted_Passes()
-    {
-        var result = validator.Validate(new CreateUserRequest(1, "Jane Doe", null, null));
+            Assert.False(result.IsValid);
+        }
 
-        Assert.True(result.IsValid);
+        [Fact]
+        public void Validate_OptionalNamesOmitted_Passes()
+        {
+            var result = validator.Validate(new CreateUserRequest(1, "Jane Doe", null, null));
+
+            Assert.True(result.IsValid);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/AddTrackToAlbumCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/AddTrackToAlbumCommandHandlerTests.cs
index 81defac..3f9d8cd 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/AddTrackToAlbumCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/AddTrackToAlbumCommandHandlerTests.cs
@@ -5,107 +5,108 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class AddTrackToAlbumCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private AddTrackToAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<AddTrackToAlbumCommandHandler>());
-
-    [Fact]
-    public async Task Handle_FirstTrack_AddsItAtNumberOne()
+    public sealed class AddTrackToAlbumCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, album, track);
+        private AddTrackToAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<AddTrackToAlbumCommandHandler>());
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_FirstTrack_AddsItAtNumberOne()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, album, track);
 
-        Assert.False(result.IsError);
-        var link = Assert.Single(await Database.AlbumHasTracks.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(1, link.TrackNumber);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+            Assert.False(result.IsError);
+            var link = Assert.Single(await Database.AlbumHasTracks.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(1, link.TrackNumber);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, Guid.NewGuid(), track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, Guid.NewGuid(), track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var album = TestEntities.UserAlbum(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, stranger, album, track);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(stranger.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var album = TestEntities.UserAlbum(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, stranger, album, track);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(stranger.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, album);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, album);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackOwnedByAnotherUser_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var otherOwner = TestEntities.User(2, "other");
-        var album = TestEntities.UserAlbum(owner.Id);
-        var foreignTrack = TestEntities.LocalTrack(otherOwner);
-        await SeedAsync(owner, otherOwner, album, foreignTrack);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, foreignTrack.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackOwnedByAnotherUser_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var otherOwner = TestEntities.User(2, "other");
+            var album = TestEntities.UserAlbum(owner.Id);
+            var foreignTrack = TestEntities.LocalTrack(otherOwner);
+            await SeedAsync(owner, otherOwner, album, foreignTrack);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, foreignTrack.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlreadyInAlbum_ReturnsConflict()
-    {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        var link = new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 };
-        await SeedAsync(owner, album, track, link);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AlreadyInAlbum_ReturnsConflict()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            var link = new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 };
+            await SeedAsync(owner, album, track, link);
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumAlreadyHasTracks_AppendsAtNextNumber()
-    {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var firstTrack = TestEntities.LocalTrack(owner, "First");
-        var secondTrack = TestEntities.LocalTrack(owner, "Second");
-        var existingLink = new AlbumHasTrack { AlbumId = album.Id, TrackId = firstTrack.Id, TrackNumber = 3 };
-        await SeedAsync(owner, album, firstTrack, secondTrack, existingLink);
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, secondTrack.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AlbumAlreadyHasTracks_AppendsAtNextNumber()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var firstTrack = TestEntities.LocalTrack(owner, "First");
+            var secondTrack = TestEntities.LocalTrack(owner, "Second");
+            var existingLink = new AlbumHasTrack { AlbumId = album.Id, TrackId = firstTrack.Id, TrackNumber = 3 };
+            await SeedAsync(owner, album, firstTrack, secondTrack, existingLink);
 
-        Assert.False(result.IsError);
-        var newLink = await Database.AlbumHasTracks.SingleAsync(l => l.TrackId == secondTrack.Id, TestContext.Current.CancellationToken);
-        Assert.Equal(4, newLink.TrackNumber);
+            var result = await CreateHandler().Handle(new AddTrackToAlbumCommand(owner.Id, album.Id, secondTrack.Id), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var newLink = await Database.AlbumHasTracks.SingleAsync(l => l.TrackId == secondTrack.Id, TestContext.Current.CancellationToken);
+            Assert.Equal(4, newLink.TrackNumber);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/CreateAlbumCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/CreateAlbumCommandHandlerTests.cs
index 8e67e95..5984dcc 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/CreateAlbumCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/CreateAlbumCommandHandlerTests.cs
@@ -3,41 +3,42 @@ using Musify.Application.Albums;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class CreateAlbumCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private CreateAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<CreateAlbumCommandHandler>());
-
-    [Fact]
-    public async Task Handle_UserExists_CreatesAlbumAndReturnsIt()
+    public sealed class CreateAlbumCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        await SeedAsync(owner);
+        private CreateAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<CreateAlbumCommandHandler>());
 
-        var command = new CreateAlbumCommand(owner.Id, "  My Album  ", "A description", 2024);
+        [Fact]
+        public async Task Handle_UserExists_CreatesAlbumAndReturnsIt()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new CreateAlbumCommand(owner.Id, "  My Album  ", "A description", 2024);
 
-        Assert.False(result.IsError);
-        Assert.Equal("My Album", result.Value.Title);
-        Assert.Equal("A description", result.Value.Description);
-        Assert.Equal(2024, result.Value.ReleaseYear);
-        Assert.Equal(owner.Id, result.Value.OwnerUserId);
-        Assert.Equal(0, result.Value.TrackCount);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var stored = await Database.UserAlbums.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("MY ALBUM", stored.NormalizedTitle);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("My Album", result.Value.Title);
+            Assert.Equal("A description", result.Value.Description);
+            Assert.Equal(2024, result.Value.ReleaseYear);
+            Assert.Equal(owner.Id, result.Value.OwnerUserId);
+            Assert.Equal(0, result.Value.TrackCount);
 
-    [Fact]
-    public async Task Handle_UserDoesNotExist_ReturnsNotFound()
-    {
-        var command = new CreateAlbumCommand(UserId: 404, "Orphan Album", Description: null, ReleaseYear: null);
+            var stored = await Database.UserAlbums.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("MY ALBUM", stored.NormalizedTitle);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UserDoesNotExist_ReturnsNotFound()
+        {
+            var command = new CreateAlbumCommand(UserId: 404, "Orphan Album", Description: null, ReleaseYear: null);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/DeleteAlbumCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/DeleteAlbumCommandHandlerTests.cs
index e59d827..a9f7fe5 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/DeleteAlbumCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/DeleteAlbumCommandHandlerTests.cs
@@ -3,44 +3,45 @@ using Musify.Application.Albums;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class DeleteAlbumCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private DeleteAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<DeleteAlbumCommandHandler>());
-
-    [Fact]
-    public async Task Handle_Owner_RemovesAlbum()
+    public sealed class DeleteAlbumCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, album);
+        private DeleteAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<DeleteAlbumCommandHandler>());
 
-        var result = await CreateHandler().Handle(new DeleteAlbumCommand(owner.Id, album.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_Owner_RemovesAlbum()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, album);
 
-        Assert.False(result.IsError);
-        Assert.Null(await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken));
-    }
+            var result = await CreateHandler().Handle(new DeleteAlbumCommand(owner.Id, album.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new DeleteAlbumCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Null(await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken));
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new DeleteAlbumCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorizedAndKeepsAlbum()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, stranger, album);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new DeleteAlbumCommand(stranger.Id, album.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorizedAndKeepsAlbum()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, stranger, album);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-        Assert.NotNull(await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken));
+            var result = await CreateHandler().Handle(new DeleteAlbumCommand(stranger.Id, album.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+            Assert.NotNull(await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumByIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumByIdQueryHandlerTests.cs
index d3d16f1..56bca64 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumByIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumByIdQueryHandlerTests.cs
@@ -4,33 +4,34 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class GetAlbumByIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private GetAlbumByIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ExistingAlbum_ReturnsItWithTrackCountAndCovers()
+    public sealed class GetAlbumByIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, album, track, new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 });
+        private GetAlbumByIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetAlbumByIdQuery(album.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ExistingAlbum_ReturnsItWithTrackCountAndCovers()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, album, track, new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 });
 
-        Assert.False(result.IsError);
-        Assert.Equal(album.Id, result.Value.Id);
-        Assert.Equal(1, result.Value.TrackCount);
-        Assert.Equal([track.Id], result.Value.CoverTrackIds);
-    }
+            var result = await CreateHandler().Handle(new GetAlbumByIdQuery(album.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetAlbumByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(album.Id, result.Value.Id);
+            Assert.Equal(1, result.Value.TrackCount);
+            Assert.Equal([track.Id], result.Value.CoverTrackIds);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetAlbumByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumTracksQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumTracksQueryHandlerTests.cs
index 2625660..6c412d9 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumTracksQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumTracksQueryHandlerTests.cs
@@ -4,35 +4,36 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class GetAlbumTracksQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private GetAlbumTracksQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_AlbumWithTracks_ReturnsThemOrderedByTrackNumber()
+    public sealed class GetAlbumTracksQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var second = TestEntities.LocalTrack(owner, "Second");
-        var first = TestEntities.LocalTrack(owner, "First");
-        await SeedAsync(
-            owner, album, second, first,
-            new AlbumHasTrack { AlbumId = album.Id, TrackId = second.Id, TrackNumber = 2 },
-            new AlbumHasTrack { AlbumId = album.Id, TrackId = first.Id, TrackNumber = 1 });
+        private GetAlbumTracksQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetAlbumTracksQuery(album.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AlbumWithTracks_ReturnsThemOrderedByTrackNumber()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var second = TestEntities.LocalTrack(owner, "Second");
+            var first = TestEntities.LocalTrack(owner, "First");
+            await SeedAsync(
+                owner, album, second, first,
+                new AlbumHasTrack { AlbumId = album.Id, TrackId = second.Id, TrackNumber = 2 },
+                new AlbumHasTrack { AlbumId = album.Id, TrackId = first.Id, TrackNumber = 1 });
 
-        Assert.False(result.IsError);
-        Assert.Equal(["First", "Second"], result.Value.Items.Select(track => track.Title));
-    }
+            var result = await CreateHandler().Handle(new GetAlbumTracksQuery(album.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetAlbumTracksQuery(Guid.NewGuid(), PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(["First", "Second"], result.Value.Items.Select(track => track.Title));
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetAlbumTracksQuery(Guid.NewGuid(), PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsByUserIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsByUserIdQueryHandlerTests.cs
index 696dd68..1bf6a66 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsByUserIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsByUserIdQueryHandlerTests.cs
@@ -3,31 +3,32 @@ using Musify.Application.Albums;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class GetAlbumsByUserIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private GetAlbumsByUserIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_UserWithAlbums_ReturnsOnlyTheirAlbums()
+    public sealed class GetAlbumsByUserIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User(1, "owner");
-        var other = TestEntities.User(2, "other");
-        await SeedAsync(owner, other, TestEntities.UserAlbum(owner.Id, "Mine"), TestEntities.UserAlbum(other.Id, "Theirs"));
+        private GetAlbumsByUserIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetAlbumsByUserIdQuery(owner.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UserWithAlbums_ReturnsOnlyTheirAlbums()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var other = TestEntities.User(2, "other");
+            await SeedAsync(owner, other, TestEntities.UserAlbum(owner.Id, "Mine"), TestEntities.UserAlbum(other.Id, "Theirs"));
 
-        Assert.False(result.IsError);
-        var album = Assert.Single(result.Value.Items);
-        Assert.Equal("Mine", album.Title);
-    }
+            var result = await CreateHandler().Handle(new GetAlbumsByUserIdQuery(owner.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetAlbumsByUserIdQuery(404, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            var album = Assert.Single(result.Value.Items);
+            Assert.Equal("Mine", album.Title);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetAlbumsByUserIdQuery(404, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsQueryHandlerTests.cs
index 7ea9b2b..c3f5c3e 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/GetAlbumsQueryHandlerTests.cs
@@ -2,47 +2,48 @@ using Musify.Application.Albums;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class GetAlbumsQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private GetAlbumsQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_NoTitleFilter_ReturnsAllAlbumsPaged()
+    public sealed class GetAlbumsQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "Alpha"), TestEntities.UserAlbum(owner.Id, "Beta"));
+        private GetAlbumsQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoTitleFilter_ReturnsAllAlbumsPaged()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "Alpha"), TestEntities.UserAlbum(owner.Id, "Beta"));
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.TotalItemCount);
-    }
+            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TitleFilter_ReturnsOnlyMatchingAlbums()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "Rock Classics"), TestEntities.UserAlbum(owner.Id, "Jazz Favorites"));
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.TotalItemCount);
+        }
 
-        var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: "rock", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TitleFilter_ReturnsOnlyMatchingAlbums()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "Rock Classics"), TestEntities.UserAlbum(owner.Id, "Jazz Favorites"));
 
-        Assert.False(result.IsError);
-        var album = Assert.Single(result.Value.Items);
-        Assert.Equal("Rock Classics", album.Title);
-    }
+            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: "rock", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PageSizeSmallerThanTotal_ReportsHasNextPage()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "One"), TestEntities.UserAlbum(owner.Id, "Two"), TestEntities.UserAlbum(owner.Id, "Three"));
+            Assert.False(result.IsError);
+            var album = Assert.Single(result.Value.Items);
+            Assert.Equal("Rock Classics", album.Title);
+        }
 
-        var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 2), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_PageSizeSmallerThanTotal_ReportsHasNextPage()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner, TestEntities.UserAlbum(owner.Id, "One"), TestEntities.UserAlbum(owner.Id, "Two"), TestEntities.UserAlbum(owner.Id, "Three"));
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.Items.Count);
-        Assert.True(result.Value.HasNextPage);
+            var result = await CreateHandler().Handle(new GetAlbumsQuery(Title: null, PageNumber: 1, PageSize: 2), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.Items.Count);
+            Assert.True(result.Value.HasNextPage);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/GetRecentlyListenedAlbumsQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/GetRecentlyListenedAlbumsQueryHandlerTests.cs
index 09824ed..28c0c0b 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/GetRecentlyListenedAlbumsQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/GetRecentlyListenedAlbumsQueryHandlerTests.cs
@@ -3,58 +3,59 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class GetRecentlyListenedAlbumsQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private GetRecentlyListenedAlbumsQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ListenedTracks_ReturnsTheirAlbumsMostRecentFirst()
+    public sealed class GetRecentlyListenedAlbumsQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var olderAlbum = TestEntities.UserAlbum(owner.Id, "Older");
-        var newerAlbum = TestEntities.UserAlbum(owner.Id, "Newer");
-        var olderTrack = TestEntities.LocalTrack(owner, "In older album");
-        var newerTrack = TestEntities.LocalTrack(owner, "In newer album");
-        await SeedAsync(
-            owner, olderAlbum, newerAlbum, olderTrack, newerTrack,
-            new AlbumHasTrack { AlbumId = olderAlbum.Id, TrackId = olderTrack.Id, TrackNumber = 1 },
-            new AlbumHasTrack { AlbumId = newerAlbum.Id, TrackId = newerTrack.Id, TrackNumber = 1 },
-            TestEntities.ListeningHistory(owner.Id, olderTrack.Id, DateTime.UtcNow.AddDays(-2)),
-            TestEntities.ListeningHistory(owner.Id, newerTrack.Id, DateTime.UtcNow.AddDays(-1)));
+        private GetRecentlyListenedAlbumsQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ListenedTracks_ReturnsTheirAlbumsMostRecentFirst()
+        {
+            var owner = TestEntities.User();
+            var olderAlbum = TestEntities.UserAlbum(owner.Id, "Older");
+            var newerAlbum = TestEntities.UserAlbum(owner.Id, "Newer");
+            var olderTrack = TestEntities.LocalTrack(owner, "In older album");
+            var newerTrack = TestEntities.LocalTrack(owner, "In newer album");
+            await SeedAsync(
+                owner, olderAlbum, newerAlbum, olderTrack, newerTrack,
+                new AlbumHasTrack { AlbumId = olderAlbum.Id, TrackId = olderTrack.Id, TrackNumber = 1 },
+                new AlbumHasTrack { AlbumId = newerAlbum.Id, TrackId = newerTrack.Id, TrackNumber = 1 },
+                TestEntities.ListeningHistory(owner.Id, olderTrack.Id, DateTime.UtcNow.AddDays(-2)),
+                TestEntities.ListeningHistory(owner.Id, newerTrack.Id, DateTime.UtcNow.AddDays(-1)));
 
-        Assert.False(result.IsError);
-        Assert.Equal(["Newer", "Older"], result.Value.Select(album => album.Title));
-    }
+            var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NoListeningHistory_ReturnsEmptyList()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner);
+            Assert.False(result.IsError);
+            Assert.Equal(["Newer", "Older"], result.Value.Select(album => album.Title));
+        }
 
-        var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoListeningHistory_ReturnsEmptyList()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner);
 
-        Assert.False(result.IsError);
-        Assert.Empty(result.Value);
-    }
+            var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_LimitLowerThanCandidates_ReturnsOnlyThatManyAlbums()
-    {
-        var owner = TestEntities.User();
-        var albums = Enumerable.Range(1, 3).Select(i => TestEntities.UserAlbum(owner.Id, $"Album {i}")).ToList();
-        var tracks = albums.Select((_, i) => TestEntities.LocalTrack(owner, $"Track {i}")).ToList();
-        var links = albums.Zip(tracks, (album, track) => new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 }).ToList();
-        var histories = tracks.Select((track, i) => TestEntities.ListeningHistory(owner.Id, track.Id, DateTime.UtcNow.AddMinutes(-i))).ToList();
-        await SeedAsync([owner, .. albums, .. tracks, .. links, .. histories]);
+            Assert.False(result.IsError);
+            Assert.Empty(result.Value);
+        }
 
-        var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 2), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_LimitLowerThanCandidates_ReturnsOnlyThatManyAlbums()
+        {
+            var owner = TestEntities.User();
+            var albums = Enumerable.Range(1, 3).Select(i => TestEntities.UserAlbum(owner.Id, $"Album {i}")).ToList();
+            var tracks = albums.Select((_, i) => TestEntities.LocalTrack(owner, $"Track {i}")).ToList();
+            var links = albums.Zip(tracks, (album, track) => new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 }).ToList();
+            var histories = tracks.Select((track, i) => TestEntities.ListeningHistory(owner.Id, track.Id, DateTime.UtcNow.AddMinutes(-i))).ToList();
+            await SeedAsync([owner, .. albums, .. tracks, .. links, .. histories]);
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.Count);
+            var result = await CreateHandler().Handle(new GetRecentlyListenedAlbumsQuery(owner.Id, Limit: 2), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.Count);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/RemoveTrackFromAlbumCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/RemoveTrackFromAlbumCommandHandlerTests.cs
index 9483258..c51431a 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/RemoveTrackFromAlbumCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/RemoveTrackFromAlbumCommandHandlerTests.cs
@@ -5,68 +5,69 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class RemoveTrackFromAlbumCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private RemoveTrackFromAlbumCommandHandler CreateHandler() =>
-        new(Database, NoOpLogger<RemoveTrackFromAlbumCommandHandler>());
-
-    [Fact]
-    public async Task Handle_TrackInAlbum_RemovesItAndRenumbersTheRest()
+    public sealed class RemoveTrackFromAlbumCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        var first = TestEntities.LocalTrack(owner, "First");
-        var second = TestEntities.LocalTrack(owner, "Second");
-        var third = TestEntities.LocalTrack(owner, "Third");
-        await SeedAsync(
-            owner, album, first, second, third,
-            new AlbumHasTrack { AlbumId = album.Id, TrackId = first.Id, TrackNumber = 1 },
-            new AlbumHasTrack { AlbumId = album.Id, TrackId = second.Id, TrackNumber = 2 },
-            new AlbumHasTrack { AlbumId = album.Id, TrackId = third.Id, TrackNumber = 3 });
+        private RemoveTrackFromAlbumCommandHandler CreateHandler() =>
+            new(Database, NoOpLogger<RemoveTrackFromAlbumCommandHandler>());
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(owner.Id, album.Id, second.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackInAlbum_RemovesItAndRenumbersTheRest()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            var first = TestEntities.LocalTrack(owner, "First");
+            var second = TestEntities.LocalTrack(owner, "Second");
+            var third = TestEntities.LocalTrack(owner, "Third");
+            await SeedAsync(
+                owner, album, first, second, third,
+                new AlbumHasTrack { AlbumId = album.Id, TrackId = first.Id, TrackNumber = 1 },
+                new AlbumHasTrack { AlbumId = album.Id, TrackId = second.Id, TrackNumber = 2 },
+                new AlbumHasTrack { AlbumId = album.Id, TrackId = third.Id, TrackNumber = 3 });
 
-        Assert.False(result.IsError);
-        var remaining = await Database.AlbumHasTracks
-            .Where(link => link.AlbumId == album.Id)
-            .OrderBy(link => link.TrackNumber)
-            .ToListAsync(TestContext.Current.CancellationToken);
-        Assert.Equal([first.Id, third.Id], remaining.Select(link => link.TrackId));
-        Assert.Equal([1, 2], remaining.Select(link => link.TrackNumber));
-    }
+            var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(owner.Id, album.Id, second.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            var remaining = await Database.AlbumHasTracks
+                .Where(link => link.AlbumId == album.Id)
+                .OrderBy(link => link.TrackNumber)
+                .ToListAsync(TestContext.Current.CancellationToken);
+            Assert.Equal([first.Id, third.Id], remaining.Select(link => link.TrackId));
+            Assert.Equal([1, 2], remaining.Select(link => link.TrackNumber));
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, stranger, album);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(stranger.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, stranger, album);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(stranger.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackNotInAlbum_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, album);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(owner.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackNotInAlbum_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, album);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new RemoveTrackFromAlbumCommand(owner.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumCommandHandlerTests.cs
index 60e379b..0975a71 100644
--- a/backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumCommandHandlerTests.cs
@@ -3,55 +3,56 @@ using Musify.Application.Albums;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Albums;
-
-public sealed class UpdateAlbumCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Albums
 {
-    private UpdateAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<UpdateAlbumCommandHandler>());
-
-    [Fact]
-    public async Task Handle_Owner_UpdatesTitleDescriptionAndReleaseYear()
+    public sealed class UpdateAlbumCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var album = TestEntities.UserAlbum(owner.Id, title: "Old Title", description: "Old", releaseYear: 2020);
-        await SeedAsync(owner, album);
+        private UpdateAlbumCommandHandler CreateHandler() => new(Database, NoOpLogger<UpdateAlbumCommandHandler>());
 
-        var command = new UpdateAlbumCommand(owner.Id, album.Id, "  New Title  ", "New description", 2025);
+        [Fact]
+        public async Task Handle_Owner_UpdatesTitleDescriptionAndReleaseYear()
+        {
+            var owner = TestEntities.User();
+            var album = TestEntities.UserAlbum(owner.Id, title: "Old Title", description: "Old", releaseYear: 2020);
+            await SeedAsync(owner, album);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new UpdateAlbumCommand(owner.Id, album.Id, "  New Title  ", "New description", 2025);
 
-        Assert.False(result.IsError);
-        Assert.Equal("New Title", result.Value.Title);
-        Assert.Equal("New description", result.Value.Description);
-        Assert.Equal(2025, result.Value.ReleaseYear);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var stored = await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("NEW TITLE", stored.NormalizedTitle);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("New Title", result.Value.Title);
+            Assert.Equal("New description", result.Value.Description);
+            Assert.Equal(2025, result.Value.ReleaseYear);
 
-    [Fact]
-    public async Task Handle_AlbumMissing_ReturnsNotFound()
-    {
-        var command = new UpdateAlbumCommand(1, Guid.NewGuid(), "Title", null, null);
+            var stored = await Database.UserAlbums.FindAsync([album.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("NEW TITLE", stored.NormalizedTitle);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var command = new UpdateAlbumCommand(1, Guid.NewGuid(), "Title", null, null);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var album = TestEntities.UserAlbum(owner.Id);
-        await SeedAsync(owner, stranger, album);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var command = new UpdateAlbumCommand(stranger.Id, album.Id, "Hijacked", null, null);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var album = TestEntities.UserAlbum(owner.Id);
+            await SeedAsync(owner, stranger, album);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new UpdateAlbumCommand(stranger.Id, album.Id, "Hijacked", null, null);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Mixes/GenerateMixesForUserCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Mixes/GenerateMixesForUserCommandHandlerTests.cs
index fe5c911..f6fddfd 100644
--- a/backend/Tests/Musify.Application.Tests/Mixes/GenerateMixesForUserCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Mixes/GenerateMixesForUserCommandHandlerTests.cs
@@ -8,99 +8,100 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Mixes;
-
-public sealed class GenerateMixesForUserCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Mixes
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private GenerateMixesForUserCommandHandler CreateHandler() => new(
-        Database, youTubeMusicService, TestConfigurations.Mix(), NoOpLogger<GenerateMixesForUserCommandHandler>());
-
-    [Fact]
-    public async Task Handle_NoListeningHistory_DoesNotCreateAnyMix()
+    public sealed class GenerateMixesForUserCommandHandlerTests : HandlerTestBase
     {
-        var user = TestEntities.User();
-        await SeedAsync(user);
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
+        private GenerateMixesForUserCommandHandler CreateHandler() => new(
+            Database, youTubeMusicService, TestConfigurations.Mix(), NoOpLogger<GenerateMixesForUserCommandHandler>());
 
-        Assert.False(result.IsError);
-        Assert.Empty(await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken));
-    }
+        [Fact]
+        public async Task Handle_NoListeningHistory_DoesNotCreateAnyMix()
+        {
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-    [Fact]
-    public async Task Handle_HistoryWithNoKnownArtists_DoesNotCreateAnyMix()
-    {
-        var user = TestEntities.User();
-        var track = TestEntities.LocalTrack(user);
-        await SeedAsync(user, track, TestEntities.ListeningHistory(user.Id, track.Id));
+            var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Empty(await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        Assert.False(result.IsError);
-        Assert.Empty(await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken));
-    }
+        [Fact]
+        public async Task Handle_HistoryWithNoKnownArtists_DoesNotCreateAnyMix()
+        {
+            var user = TestEntities.User();
+            var track = TestEntities.LocalTrack(user);
+            await SeedAsync(user, track, TestEntities.ListeningHistory(user.Id, track.Id));
 
-    [Fact]
-    public async Task Handle_SeedArtistWithYouTubeAndLocalCandidates_ReplacesPreviousMixes()
-    {
-        youTubeMusicService
-            .SearchSongsAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns(new YouTubeSearchResult(
-                [new YouTubeSongResult("yt-1", "YouTube Song", "Seed Artist", "Album", 200, "https://img/thumb.jpg", IsExplicit: false, [] )],
-                ContinuationToken: string.Empty));
-        youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
+            var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
 
-        var user = TestEntities.User();
-        var artist = TestEntities.Artist("Seed Artist");
-        var listenedTrack = TestEntities.ExternalTrack(externalId: "listened", title: "Listened Track");
-        var otherTrackByArtist = TestEntities.ExternalTrack(externalId: "not-listened", title: "Other Track");
+            Assert.False(result.IsError);
+            Assert.Empty(await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        var staleMix = TestEntities.Mix(user.Id, "Stale Mix");
-        var staleItem = TestEntities.MixItem(staleMix.Id, title: "Stale Item");
+        [Fact]
+        public async Task Handle_SeedArtistWithYouTubeAndLocalCandidates_ReplacesPreviousMixes()
+        {
+            youTubeMusicService
+                .SearchSongsAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new YouTubeSearchResult(
+                    [new YouTubeSongResult("yt-1", "YouTube Song", "Seed Artist", "Album", 200, "https://img/thumb.jpg", IsExplicit: false, [] )],
+                    ContinuationToken: string.Empty));
+            youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
 
-        await SeedAsync(
-            user, artist, listenedTrack, otherTrackByArtist, staleMix, staleItem,
-            new TrackArtist { TrackId = listenedTrack.Id, ArtistId = artist.Id, Position = 0 },
-            new TrackArtist { TrackId = otherTrackByArtist.Id, ArtistId = artist.Id, Position = 0 },
-            TestEntities.ListeningHistory(user.Id, listenedTrack.Id));
+            var user = TestEntities.User();
+            var artist = TestEntities.Artist("Seed Artist");
+            var listenedTrack = TestEntities.ExternalTrack(externalId: "listened", title: "Listened Track");
+            var otherTrackByArtist = TestEntities.ExternalTrack(externalId: "not-listened", title: "Other Track");
 
-        var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
+            var staleMix = TestEntities.Mix(user.Id, "Stale Mix");
+            var staleItem = TestEntities.MixItem(staleMix.Id, title: "Stale Item");
 
-        Assert.False(result.IsError);
-        var mixes = await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken);
-        Assert.NotEmpty(mixes);
-        Assert.DoesNotContain(mixes, mix => mix.Title == "Stale Mix");
-        Assert.Empty(await Database.MixItems.Where(item => item.MixId == staleMix.Id).ToListAsync(TestContext.Current.CancellationToken));
-    }
+            await SeedAsync(
+                user, artist, listenedTrack, otherTrackByArtist, staleMix, staleItem,
+                new TrackArtist { TrackId = listenedTrack.Id, ArtistId = artist.Id, Position = 0 },
+                new TrackArtist { TrackId = otherTrackByArtist.Id, ArtistId = artist.Id, Position = 0 },
+                TestEntities.ListeningHistory(user.Id, listenedTrack.Id));
 
-    [Fact]
-    public async Task Handle_YouTubeSourceUnavailable_StillCreatesMixesFromLocalCandidatesOnly()
-    {
-        // Simulates IYouTubeMusicService.SearchSongsAsync as it behaves when the YouTube source is
-        // disabled (DisabledYouTubeMusicService, see Infrastructure): every call fails. Mix
-        // generation must degrade to local-only candidates instead of failing the whole command.
-        youTubeMusicService
-            .SearchSongsAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns(Error.Forbidden(description: "The YouTube Music source is disabled."));
+            var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
 
-        var user = TestEntities.User();
-        var artist = TestEntities.Artist("Seed Artist");
-        var listenedTrack = TestEntities.ExternalTrack(externalId: "listened", title: "Listened Track");
-        var otherTrackByArtist = TestEntities.ExternalTrack(externalId: "not-listened", title: "Other Track");
+            Assert.False(result.IsError);
+            var mixes = await Database.Mixes.ToListAsync(TestContext.Current.CancellationToken);
+            Assert.NotEmpty(mixes);
+            Assert.DoesNotContain(mixes, mix => mix.Title == "Stale Mix");
+            Assert.Empty(await Database.MixItems.Where(item => item.MixId == staleMix.Id).ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        await SeedAsync(
-            user, artist, listenedTrack, otherTrackByArtist,
-            new TrackArtist { TrackId = listenedTrack.Id, ArtistId = artist.Id, Position = 0 },
-            new TrackArtist { TrackId = otherTrackByArtist.Id, ArtistId = artist.Id, Position = 0 },
-            TestEntities.ListeningHistory(user.Id, listenedTrack.Id));
+        [Fact]
+        public async Task Handle_YouTubeSourceUnavailable_StillCreatesMixesFromLocalCandidatesOnly()
+        {
+            // Simulates IYouTubeMusicService.SearchSongsAsync as it behaves when the YouTube source is
+            // disabled (DisabledYouTubeMusicService, see Infrastructure): every call fails. Mix
+            // generation must degrade to local-only candidates instead of failing the whole command.
+            youTubeMusicService
+                .SearchSongsAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(Error.Forbidden(description: "The YouTube Music source is disabled."));
 
-        var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
+            var user = TestEntities.User();
+            var artist = TestEntities.Artist("Seed Artist");
+            var listenedTrack = TestEntities.ExternalTrack(externalId: "listened", title: "Listened Track");
+            var otherTrackByArtist = TestEntities.ExternalTrack(externalId: "not-listened", title: "Other Track");
 
-        Assert.False(result.IsError);
-        var items = await Database.MixItems.ToListAsync(TestContext.Current.CancellationToken);
-        Assert.NotEmpty(items);
-        Assert.All(items, item => Assert.Equal(MixItemSource.Musify, item.Source));
+            await SeedAsync(
+                user, artist, listenedTrack, otherTrackByArtist,
+                new TrackArtist { TrackId = listenedTrack.Id, ArtistId = artist.Id, Position = 0 },
+                new TrackArtist { TrackId = otherTrackByArtist.Id, ArtistId = artist.Id, Position = 0 },
+                TestEntities.ListeningHistory(user.Id, listenedTrack.Id));
+
+            var result = await CreateHandler().Handle(new GenerateMixesForUserCommand(user.Id), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var items = await Database.MixItems.ToListAsync(TestContext.Current.CancellationToken);
+            Assert.NotEmpty(items);
+            Assert.All(items, item => Assert.Equal(MixItemSource.Musify, item.Source));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Mixes/GetMixByIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Mixes/GetMixByIdQueryHandlerTests.cs
index 118208e..a25ceda 100644
--- a/backend/Tests/Musify.Application.Tests/Mixes/GetMixByIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Mixes/GetMixByIdQueryHandlerTests.cs
@@ -3,45 +3,46 @@ using Musify.Application.Mixes;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Mixes;
-
-public sealed class GetMixByIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Mixes
 {
-    private GetMixByIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_OwnedMix_ReturnsItWithOrderedItems()
+    public sealed class GetMixByIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var mix = TestEntities.Mix(owner.Id, "Discovery");
-        var second = TestEntities.MixItem(mix.Id, position: 1, title: "Second");
-        var first = TestEntities.MixItem(mix.Id, position: 0, title: "First");
-        await SeedAsync(owner, mix, second, first);
+        private GetMixByIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetMixByIdQuery(owner.Id, mix.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_OwnedMix_ReturnsItWithOrderedItems()
+        {
+            var owner = TestEntities.User();
+            var mix = TestEntities.Mix(owner.Id, "Discovery");
+            var second = TestEntities.MixItem(mix.Id, position: 1, title: "Second");
+            var first = TestEntities.MixItem(mix.Id, position: 0, title: "First");
+            await SeedAsync(owner, mix, second, first);
 
-        Assert.False(result.IsError);
-        Assert.Equal("Discovery", result.Value.Title);
-        Assert.Equal(["First", "Second"], result.Value.Items.Select(item => item.Title));
-    }
+            var result = await CreateHandler().Handle(new GetMixByIdQuery(owner.Id, mix.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_MixMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetMixByIdQuery(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("Discovery", result.Value.Title);
+            Assert.Equal(["First", "Second"], result.Value.Items.Select(item => item.Title));
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_MixMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetMixByIdQuery(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_MixBelongsToAnotherUser_ReturnsNotFound()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var mix = TestEntities.Mix(owner.Id);
-        await SeedAsync(owner, mix);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new GetMixByIdQuery(2, mix.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_MixBelongsToAnotherUser_ReturnsNotFound()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var mix = TestEntities.Mix(owner.Id);
+            await SeedAsync(owner, mix);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new GetMixByIdQuery(2, mix.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Mixes/GetMixesByUserIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Mixes/GetMixesByUserIdQueryHandlerTests.cs
index 9533607..d5ec0d9 100644
--- a/backend/Tests/Musify.Application.Tests/Mixes/GetMixesByUserIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Mixes/GetMixesByUserIdQueryHandlerTests.cs
@@ -2,37 +2,38 @@ using Musify.Application.Mixes;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.Mixes;
-
-public sealed class GetMixesByUserIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Mixes
 {
-    private GetMixesByUserIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ReturnsOnlyThatUsersMixesOrderedByPosition()
+    public sealed class GetMixesByUserIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User(1, "owner");
-        var other = TestEntities.User(2, "other");
-        var second = TestEntities.Mix(owner.Id, "Second", position: 1);
-        var first = TestEntities.Mix(owner.Id, "First", position: 0);
-        var theirs = TestEntities.Mix(other.Id, "Theirs");
-        await SeedAsync(owner, other, second, first, theirs);
+        private GetMixesByUserIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetMixesByUserIdQuery(owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ReturnsOnlyThatUsersMixesOrderedByPosition()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var other = TestEntities.User(2, "other");
+            var second = TestEntities.Mix(owner.Id, "Second", position: 1);
+            var first = TestEntities.Mix(owner.Id, "First", position: 0);
+            var theirs = TestEntities.Mix(other.Id, "Theirs");
+            await SeedAsync(owner, other, second, first, theirs);
 
-        Assert.False(result.IsError);
-        Assert.Equal(["First", "Second"], result.Value.Select(mix => mix.Title));
-    }
+            var result = await CreateHandler().Handle(new GetMixesByUserIdQuery(owner.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NoMixes_ReturnsEmptyList()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner);
+            Assert.False(result.IsError);
+            Assert.Equal(["First", "Second"], result.Value.Select(mix => mix.Title));
+        }
 
-        var result = await CreateHandler().Handle(new GetMixesByUserIdQuery(owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoMixes_ReturnsEmptyList()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner);
 
-        Assert.False(result.IsError);
-        Assert.Empty(result.Value);
+            var result = await CreateHandler().Handle(new GetMixesByUserIdQuery(owner.Id), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Empty(result.Value);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/AddTrackToPlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/AddTrackToPlayListCommandHandlerTests.cs
index 00c9078..df88fc1 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/AddTrackToPlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/AddTrackToPlayListCommandHandlerTests.cs
@@ -5,88 +5,89 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class AddTrackToPlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private AddTrackToPlayListCommandHandler CreateHandler() => new(Database, NoOpLogger<AddTrackToPlayListCommandHandler>());
-
-    [Fact]
-    public async Task Handle_FirstTrack_AddsItAtPositionZero()
+    public sealed class AddTrackToPlayListCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, playList, track);
+        private AddTrackToPlayListCommandHandler CreateHandler() => new(Database, NoOpLogger<AddTrackToPlayListCommandHandler>());
 
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_FirstTrack_AddsItAtPositionZero()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, playList, track);
 
-        Assert.False(result.IsError);
-        var link = Assert.Single(await Database.PlayListHasTracks.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(0, link.Position);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListAlreadyHasTracks_AppendsAtNextPosition()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var existingTrack = TestEntities.LocalTrack(owner, "Existing");
-        var newTrack = TestEntities.LocalTrack(owner, "New");
-        await SeedAsync(
-            owner, playList, existingTrack, newTrack,
-            new PlayListHasTrack { PlayListId = playList.Id, TrackId = existingTrack.Id, Position = 0 });
+            Assert.False(result.IsError);
+            var link = Assert.Single(await Database.PlayListHasTracks.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(0, link.Position);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, newTrack.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_PlayListAlreadyHasTracks_AppendsAtNextPosition()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var existingTrack = TestEntities.LocalTrack(owner, "Existing");
+            var newTrack = TestEntities.LocalTrack(owner, "New");
+            await SeedAsync(
+                owner, playList, existingTrack, newTrack,
+                new PlayListHasTrack { PlayListId = playList.Id, TrackId = existingTrack.Id, Position = 0 });
 
-        Assert.False(result.IsError);
-        var newLink = await Database.PlayListHasTracks.SingleAsync(link => link.TrackId == newTrack.Id, TestContext.Current.CancellationToken);
-        Assert.Equal(1, newLink.Position);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, newTrack.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            var newLink = await Database.PlayListHasTracks.SingleAsync(link => link.TrackId == newTrack.Id, TestContext.Current.CancellationToken);
+            Assert.Equal(1, newLink.Position);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, stranger, playList);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(stranger.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(stranger.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, playList);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, playList);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackAlreadyInPlayList_ReturnsConflict()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackAlreadyInPlayList_ReturnsConflict()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/AddYouTubeTrackToPlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/AddYouTubeTrackToPlayListCommandHandlerTests.cs
index b24930b..eeb832b 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/AddYouTubeTrackToPlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/AddYouTubeTrackToPlayListCommandHandlerTests.cs
@@ -8,97 +8,98 @@ using Musify.Domain.Entities;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class AddYouTubeTrackToPlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private AddYouTubeTrackToPlayListCommandHandler CreateHandler()
+    public sealed class AddYouTubeTrackToPlayListCommandHandlerTests : HandlerTestBase
     {
-        var provisioner = new YouTubeTrackProvisioner(
-            Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        return new AddYouTubeTrackToPlayListCommandHandler(
-            Database,
-            eventBus,
-            youTubeMusicService,
-            provisioner,
-            TestConfigurations.Storage(),
-            TestConfigurations.Track(),
-            NoOpLogger<AddYouTubeTrackToPlayListCommandHandler>());
-    }
+        private AddYouTubeTrackToPlayListCommandHandler CreateHandler()
+        {
+            var provisioner = new YouTubeTrackProvisioner(
+                Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
 
-    private static YouTubeSongResult BuildSong(string videoId) => new(
-        videoId, "Song Title", "Song Artist", "Song Album", 200, "https://img.example/thumb.jpg", false,
-        [new YouTubeArtistRef("artist-id", "Song Artist")]);
+            return new AddYouTubeTrackToPlayListCommandHandler(
+                Database,
+                eventBus,
+                youTubeMusicService,
+                provisioner,
+                TestConfigurations.Storage(),
+                TestConfigurations.Track(),
+                NoOpLogger<AddYouTubeTrackToPlayListCommandHandler>());
+        }
 
-    [Fact]
-    public async Task Handle_TrackAlreadyProcessedAndNotLinked_AddsItWithoutQueuingDownload()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.ExternalTrack(externalId: "abc123");
-        await SeedAsync(owner, playList, track);
+        private static YouTubeSongResult BuildSong(string videoId) => new(
+            videoId, "Song Title", "Song Artist", "Song Album", 200, "https://img.example/thumb.jpg", false,
+            [new YouTubeArtistRef("artist-id", "Song Artist")]);
 
-        var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackAlreadyProcessedAndNotLinked_AddsItWithoutQueuingDownload()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.ExternalTrack(externalId: "abc123");
+            await SeedAsync(owner, playList, track);
 
-        Assert.False(result.IsError);
-        Assert.Single(await Database.PlayListHasTracks.ToListAsync(TestContext.Current.CancellationToken));
-        await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.DownloadYouTubeTrackEvent>(), Arg.Any<CancellationToken>());
-    }
+            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UnknownVideo_ProvisionsTrackAndQueuesDownload()
-    {
-        youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>()).Returns(BuildSong("new-video"));
-        youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
+            Assert.False(result.IsError);
+            Assert.Single(await Database.PlayListHasTracks.ToListAsync(TestContext.Current.CancellationToken));
+            await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.DownloadYouTubeTrackEvent>(), Arg.Any<CancellationToken>());
+        }
 
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, playList);
+        [Fact]
+        public async Task Handle_UnknownVideo_ProvisionsTrackAndQueuesDownload()
+        {
+            youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>()).Returns(BuildSong("new-video"));
+            youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
 
-        var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "new-video"), TestContext.Current.CancellationToken);
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, playList);
 
-        Assert.False(result.IsError);
-        Assert.Equal("Song Title", result.Value.Title);
-        var track = await Database.ExternalTracks.SingleAsync(t => t.ExternalId == "new-video", TestContext.Current.CancellationToken);
-        Assert.True(track.Audio.DownloadRequested);
-        await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DownloadYouTubeTrackEvent>(), Arg.Any<CancellationToken>());
-    }
+            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "new-video"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(1, Guid.NewGuid(), "abc123"), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("Song Title", result.Value.Title);
+            var track = await Database.ExternalTracks.SingleAsync(t => t.ExternalId == "new-video", TestContext.Current.CancellationToken);
+            Assert.True(track.Audio.DownloadRequested);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DownloadYouTubeTrackEvent>(), Arg.Any<CancellationToken>());
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(1, Guid.NewGuid(), "abc123"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, stranger, playList);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(stranger.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(stranger.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackAlreadyLinked_ReturnsConflict()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.ExternalTrack(externalId: "abc123");
-        await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackAlreadyLinked_ReturnsConflict()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.ExternalTrack(externalId: "abc123");
+            await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/CreatePlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/CreatePlayListCommandHandlerTests.cs
index 84a8883..ee7035f 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/CreatePlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/CreatePlayListCommandHandlerTests.cs
@@ -6,80 +6,81 @@ using Musify.Application.Tests.TestSupport;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class CreatePlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
-    private CreatePlayListCommandHandler CreateHandler() => new(
-        eventBus,
-        Database,
-        new UploadIntentValidator(Database, storageService),
-        NoOpLogger<CreatePlayListCommandHandler>(),
-        TestConfigurations.Storage(),
-        TestConfigurations.PlayList(),
-        TestConfigurations.UploadIntent());
-
-    [Fact]
-    public async Task Handle_NoPictureIntent_CreatesPlayListWithPresetPictures()
+    public sealed class CreatePlayListCommandHandlerTests : HandlerTestBase
     {
-        var user = TestEntities.User();
-        await SeedAsync(user);
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
 
-        var command = new CreatePlayListCommand(user.Id, "My Playlist", "A description", PictureIntentId: null);
+        private CreatePlayListCommandHandler CreateHandler() => new(
+            eventBus,
+            Database,
+            new UploadIntentValidator(Database, storageService),
+            NoOpLogger<CreatePlayListCommandHandler>(),
+            TestConfigurations.Storage(),
+            TestConfigurations.PlayList(),
+            TestConfigurations.UploadIntent());
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoPictureIntent_CreatesPlayListWithPresetPictures()
+        {
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-        Assert.False(result.IsError);
-        Assert.Equal("My Playlist", result.Value.Name);
-        Assert.Equal("PresetSmallPicture.webp", result.Value.SmallImageKeyName);
-        await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.CreatePlayListResourcesEvent>(), Arg.Any<CancellationToken>());
-    }
+            var command = new CreatePlayListCommand(user.Id, "My Playlist", "A description", PictureIntentId: null);
 
-    [Fact]
-    public async Task Handle_WithValidPictureIntent_PublishesResourcesEvent()
-    {
-        storageService
-            .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns(new ObjectMetaData("image/webp", 1024));
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var user = TestEntities.User();
-        var intent = TestEntities.UploadIntent(user.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.PlayListPicture, objectName: "cover.webp");
-        await SeedAsync(user, intent);
+            Assert.False(result.IsError);
+            Assert.Equal("My Playlist", result.Value.Name);
+            Assert.Equal("PresetSmallPicture.webp", result.Value.SmallImageKeyName);
+            await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.CreatePlayListResourcesEvent>(), Arg.Any<CancellationToken>());
+        }
 
-        var command = new CreatePlayListCommand(user.Id, "My Playlist", null, intent.Id);
+        [Fact]
+        public async Task Handle_WithValidPictureIntent_PublishesResourcesEvent()
+        {
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 1024));
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var user = TestEntities.User();
+            var intent = TestEntities.UploadIntent(user.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.PlayListPicture, objectName: "cover.webp");
+            await SeedAsync(user, intent);
 
-        Assert.False(result.IsError);
-        var stored = await Database.PlayLists.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("cover.webp", stored.Pictures.OriginalName);
-        await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.CreatePlayListResourcesEvent>(), Arg.Any<CancellationToken>());
-    }
+            var command = new CreatePlayListCommand(user.Id, "My Playlist", null, intent.Id);
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var command = new CreatePlayListCommand(404, "Orphan Playlist", null, null);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            var stored = await Database.PlayLists.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("cover.webp", stored.Pictures.OriginalName);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.CreatePlayListResourcesEvent>(), Arg.Any<CancellationToken>());
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var command = new CreatePlayListCommand(404, "Orphan Playlist", null, null);
 
-    [Fact]
-    public async Task Handle_PictureIntentNotFound_ReturnsError()
-    {
-        var user = TestEntities.User();
-        await SeedAsync(user);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var command = new CreatePlayListCommand(user.Id, "My Playlist", null, Guid.NewGuid());
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_PictureIntentNotFound_ReturnsError()
+        {
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-        Assert.True(result.IsError);
+            var command = new CreatePlayListCommand(user.Id, "My Playlist", null, Guid.NewGuid());
+
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.True(result.IsError);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/DeletePlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/DeletePlayListCommandHandlerTests.cs
index 7965b4e..2c637a8 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/DeletePlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/DeletePlayListCommandHandlerTests.cs
@@ -6,48 +6,49 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class DeletePlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-
-    private DeletePlayListCommandHandler CreateHandler() => new(Database, eventBus, NoOpLogger<DeletePlayListCommandHandler>());
-
-    [Fact]
-    public async Task Handle_Owner_MarksPlayListAsRemoving()
+    public sealed class DeletePlayListCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, playList);
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
 
-        var result = await CreateHandler().Handle(new DeletePlayListCommand(owner.Id, playList.Id), TestContext.Current.CancellationToken);
+        private DeletePlayListCommandHandler CreateHandler() => new(Database, eventBus, NoOpLogger<DeletePlayListCommandHandler>());
 
-        Assert.False(result.IsError);
-        var stored = await Database.PlayLists.FindAsync([playList.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal(LifeCycleStatus.Removing, stored.LifeCycleStatus);
-        await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DeletePlayListEvent>(), Arg.Any<CancellationToken>());
-    }
+        [Fact]
+        public async Task Handle_Owner_MarksPlayListAsRemoving()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, playList);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new DeletePlayListCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
+            var result = await CreateHandler().Handle(new DeletePlayListCommand(owner.Id, playList.Id), TestContext.Current.CancellationToken);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            Assert.False(result.IsError);
+            var stored = await Database.PlayLists.FindAsync([playList.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal(LifeCycleStatus.Removing, stored.LifeCycleStatus);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DeletePlayListEvent>(), Arg.Any<CancellationToken>());
+        }
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, stranger, playList);
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new DeletePlayListCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new DeletePlayListCommand(stranger.Id, playList.Id), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
+
+            var result = await CreateHandler().Handle(new DeletePlayListCommand(stranger.Id, playList.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListByIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListByIdQueryHandlerTests.cs
index 22d08d8..5a68047 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListByIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListByIdQueryHandlerTests.cs
@@ -4,32 +4,33 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class GetPlayListByIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private GetPlayListByIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ExistingPlayList_ReturnsItWithCoverTrackIds()
+    public sealed class GetPlayListByIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
+        private GetPlayListByIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetPlayListByIdQuery(playList.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ExistingPlayList_ReturnsItWithCoverTrackIds()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
-        Assert.False(result.IsError);
-        Assert.Equal(playList.Name, result.Value.Name);
-        Assert.Equal([track.Id], result.Value.CoverTrackIds);
-    }
+            var result = await CreateHandler().Handle(new GetPlayListByIdQuery(playList.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetPlayListByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(playList.Name, result.Value.Name);
+            Assert.Equal([track.Id], result.Value.CoverTrackIds);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetPlayListByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListCoverQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListCoverQueryHandlerTests.cs
index e2f4600..591322d 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListCoverQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListCoverQueryHandlerTests.cs
@@ -3,35 +3,36 @@ using Musify.Application.PlayLists;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class GetPlayListCoverQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private GetPlayListCoverQueryHandler CreateHandler() =>
-        new(Database, TestConfigurations.Storage("covers-bucket"), TestConfigurations.PlayList());
-
-    [Theory]
-    [InlineData("small", "small.webp")]
-    [InlineData("large", "large.webp")]
-    [InlineData("medium", "medium.webp")]
-    public async Task Handle_ExistingPlayList_ReturnsRequestedSize(string size, string expectedFileName)
+    public sealed class GetPlayListCoverQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, playList);
+        private GetPlayListCoverQueryHandler CreateHandler() =>
+            new(Database, TestConfigurations.Storage("covers-bucket"), TestConfigurations.PlayList());
 
-        var result = await CreateHandler().Handle(new GetPlayListCoverQuery(playList.Id, size), TestContext.Current.CancellationToken);
+        [Theory]
+        [InlineData("small", "small.webp")]
+        [InlineData("large", "large.webp")]
+        [InlineData("medium", "medium.webp")]
+        public async Task Handle_ExistingPlayList_ReturnsRequestedSize(string size, string expectedFileName)
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, playList);
 
-        Assert.False(result.IsError);
-        Assert.Equal("covers-bucket", result.Value.Bucket);
-        Assert.EndsWith(expectedFileName, result.Value.Key);
-    }
+            var result = await CreateHandler().Handle(new GetPlayListCoverQuery(playList.Id, size), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetPlayListCoverQuery(Guid.NewGuid(), "small"), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("covers-bucket", result.Value.Bucket);
+            Assert.EndsWith(expectedFileName, result.Value.Key);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetPlayListCoverQuery(Guid.NewGuid(), "small"), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListTracksQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListTracksQueryHandlerTests.cs
index 3f1e1e5..5642616 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListTracksQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListTracksQueryHandlerTests.cs
@@ -4,35 +4,36 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class GetPlayListTracksQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private GetPlayListTracksQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_TracksOrderedByPosition_ReturnsThemInOrder()
+    public sealed class GetPlayListTracksQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var second = TestEntities.LocalTrack(owner, "Second");
-        var first = TestEntities.LocalTrack(owner, "First");
-        await SeedAsync(
-            owner, playList, second, first,
-            new PlayListHasTrack { PlayListId = playList.Id, TrackId = second.Id, Position = 1 },
-            new PlayListHasTrack { PlayListId = playList.Id, TrackId = first.Id, Position = 0 });
+        private GetPlayListTracksQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetPlayListTracksQuery(playList.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TracksOrderedByPosition_ReturnsThemInOrder()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var second = TestEntities.LocalTrack(owner, "Second");
+            var first = TestEntities.LocalTrack(owner, "First");
+            await SeedAsync(
+                owner, playList, second, first,
+                new PlayListHasTrack { PlayListId = playList.Id, TrackId = second.Id, Position = 1 },
+                new PlayListHasTrack { PlayListId = playList.Id, TrackId = first.Id, Position = 0 });
 
-        Assert.False(result.IsError);
-        Assert.Equal(["First", "Second"], result.Value.Items.Select(track => track.Title));
-    }
+            var result = await CreateHandler().Handle(new GetPlayListTracksQuery(playList.Id, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetPlayListTracksQuery(Guid.NewGuid(), PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(["First", "Second"], result.Value.Items.Select(track => track.Title));
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetPlayListTracksQuery(Guid.NewGuid(), PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsByUserIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsByUserIdQueryHandlerTests.cs
index 157ff05..6a3bd17 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsByUserIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsByUserIdQueryHandlerTests.cs
@@ -3,40 +3,41 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.ValueObjects;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class GetPlayListsByUserIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private GetPlayListsByUserIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ReturnsOnlyActivePlayListsForThatUser()
+    public sealed class GetPlayListsByUserIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User(1, "owner");
-        var other = TestEntities.User(2, "other");
-        await SeedAsync(
-            owner, other,
-            TestEntities.PlayList(owner.Id, "Mine"),
-            TestEntities.PlayList(owner.Id, "Being removed", lifeCycleStatus: LifeCycleStatus.Removing),
-            TestEntities.PlayList(other.Id, "Theirs"));
+        private GetPlayListsByUserIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetPlayListsByUserIdQuery(owner.Id, Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ReturnsOnlyActivePlayListsForThatUser()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var other = TestEntities.User(2, "other");
+            await SeedAsync(
+                owner, other,
+                TestEntities.PlayList(owner.Id, "Mine"),
+                TestEntities.PlayList(owner.Id, "Being removed", lifeCycleStatus: LifeCycleStatus.Removing),
+                TestEntities.PlayList(other.Id, "Theirs"));
 
-        Assert.False(result.IsError);
-        var playList = Assert.Single(result.Value.Items);
-        Assert.Equal("Mine", playList.Name);
-    }
+            var result = await CreateHandler().Handle(new GetPlayListsByUserIdQuery(owner.Id, Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NameFilter_ReturnsOnlyMatchingPlayLists()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner, TestEntities.PlayList(owner.Id, "Road Trip"), TestEntities.PlayList(owner.Id, "Study Focus"));
+            Assert.False(result.IsError);
+            var playList = Assert.Single(result.Value.Items);
+            Assert.Equal("Mine", playList.Name);
+        }
 
-        var result = await CreateHandler().Handle(new GetPlayListsByUserIdQuery(owner.Id, Name: "road", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NameFilter_ReturnsOnlyMatchingPlayLists()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner, TestEntities.PlayList(owner.Id, "Road Trip"), TestEntities.PlayList(owner.Id, "Study Focus"));
 
-        Assert.False(result.IsError);
-        var playList = Assert.Single(result.Value.Items);
-        Assert.Equal("Road Trip", playList.Name);
+            var result = await CreateHandler().Handle(new GetPlayListsByUserIdQuery(owner.Id, Name: "road", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var playList = Assert.Single(result.Value.Items);
+            Assert.Equal("Road Trip", playList.Name);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsQueryHandlerTests.cs
index 3c8b364..ba64fa9 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListsQueryHandlerTests.cs
@@ -2,30 +2,31 @@ using Musify.Application.PlayLists;
 using Musify.Application.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class GetPlayListsQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private GetPlayListsQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ReturnsEveryPlayListPaged()
+    public sealed class GetPlayListsQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        await SeedAsync(owner, TestEntities.PlayList(owner.Id, "One"), TestEntities.PlayList(owner.Id, "Two"));
+        private GetPlayListsQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetPlayListsQuery(PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ReturnsEveryPlayListPaged()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner, TestEntities.PlayList(owner.Id, "One"), TestEntities.PlayList(owner.Id, "Two"));
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.TotalItemCount);
-    }
+            var result = await CreateHandler().Handle(new GetPlayListsQuery(PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NoPlayLists_ReturnsEmptyPage()
-    {
-        var result = await CreateHandler().Handle(new GetPlayListsQuery(PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.TotalItemCount);
+        }
 
-        Assert.False(result.IsError);
-        Assert.Empty(result.Value.Items);
+        [Fact]
+        public async Task Handle_NoPlayLists_ReturnsEmptyPage()
+        {
+            var result = await CreateHandler().Handle(new GetPlayListsQuery(PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Empty(result.Value.Items);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/RemoveTrackFromPlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/RemoveTrackFromPlayListCommandHandlerTests.cs
index 33311bc..81e1d59 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/RemoveTrackFromPlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/RemoveTrackFromPlayListCommandHandlerTests.cs
@@ -4,56 +4,57 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class RemoveTrackFromPlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private RemoveTrackFromPlayListCommandHandler CreateHandler() => new(Database, NoOpLogger<RemoveTrackFromPlayListCommandHandler>());
-
-    [Fact]
-    public async Task Handle_TrackInPlayList_RemovesTheLink()
+    public sealed class RemoveTrackFromPlayListCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
+        private RemoveTrackFromPlayListCommandHandler CreateHandler() => new(Database, NoOpLogger<RemoveTrackFromPlayListCommandHandler>());
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackInPlayList_RemovesTheLink()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
-        Assert.False(result.IsError);
-        Assert.Empty(Database.PlayListHasTracks);
-    }
+            var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Empty(Database.PlayListHasTracks);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, stranger, playList);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(stranger.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(stranger.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackNotLinked_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, playList);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(owner.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_TrackNotLinked_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, playList);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(owner.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/RequestPlayListPictureUploadCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/RequestPlayListPictureUploadCommandHandlerTests.cs
index 78eab3f..7a73cb4 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/RequestPlayListPictureUploadCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/RequestPlayListPictureUploadCommandHandlerTests.cs
@@ -8,67 +8,68 @@ using Musify.Application.Tests.TestSupport;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class RequestPlayListPictureUploadCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
-    private RequestPlayListPictureUploadCommandHandler CreateHandler(UploadIntentConfiguration? uploadIntentConfig = null)
+    public sealed class RequestPlayListPictureUploadCommandHandlerTests : HandlerTestBase
     {
-        storageService
-            .GetUploadUrlAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<TimeSpan>(), Arg.Any<CancellationToken>())
-            .Returns("https://storage.musify.test/presigned-upload");
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
 
-        return new RequestPlayListPictureUploadCommandHandler(
-            Database,
-            new UploadIntentValidator(Database, storageService),
-            storageService,
-            NoOpLogger<RequestPlayListPictureUploadCommandHandler>(),
-            TestConfigurations.Storage(),
-            TestConfigurations.PlayList(),
-            uploadIntentConfig ?? TestConfigurations.UploadIntent());
-    }
+        private RequestPlayListPictureUploadCommandHandler CreateHandler(UploadIntentConfiguration? uploadIntentConfig = null)
+        {
+            storageService
+                .GetUploadUrlAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<TimeSpan>(), Arg.Any<CancellationToken>())
+                .Returns("https://storage.musify.test/presigned-upload");
 
-    [Fact]
-    public async Task Handle_UserExists_IssuesUploadUrlAndCreatesIntent()
-    {
-        var user = TestEntities.User();
-        await SeedAsync(user);
+            return new RequestPlayListPictureUploadCommandHandler(
+                Database,
+                new UploadIntentValidator(Database, storageService),
+                storageService,
+                NoOpLogger<RequestPlayListPictureUploadCommandHandler>(),
+                TestConfigurations.Storage(),
+                TestConfigurations.PlayList(),
+                uploadIntentConfig ?? TestConfigurations.UploadIntent());
+        }
 
-        var command = new RequestPlayListPictureUploadCommand(user.Id, "webp", "image/webp");
+        [Fact]
+        public async Task Handle_UserExists_IssuesUploadUrlAndCreatesIntent()
+        {
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new RequestPlayListPictureUploadCommand(user.Id, "webp", "image/webp");
 
-        Assert.False(result.IsError);
-        Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.UploadUrl);
-        Assert.Single(await Database.UploadIntents.ToListAsync(TestContext.Current.CancellationToken));
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var command = new RequestPlayListPictureUploadCommand(404, "webp", "image/webp");
+            Assert.False(result.IsError);
+            Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.UploadUrl);
+            Assert.Single(await Database.UploadIntents.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var command = new RequestPlayListPictureUploadCommand(404, "webp", "image/webp");
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UserOverByteQuota_ReturnsValidationErrorAndCreatesNoIntent()
-    {
-        var config = TestConfigurations.UploadIntent();
-        config.MaxActiveUploadBytesPerUser = 100;
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var user = TestEntities.User();
-        await SeedAsync(user);
+        [Fact]
+        public async Task Handle_UserOverByteQuota_ReturnsValidationErrorAndCreatesNoIntent()
+        {
+            var config = TestConfigurations.UploadIntent();
+            config.MaxActiveUploadBytesPerUser = 100;
 
-        var command = new RequestPlayListPictureUploadCommand(user.Id, "webp", "image/webp", ExpectedSizeBytes: 1_000_000);
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-        var result = await CreateHandler(config).Handle(command, TestContext.Current.CancellationToken);
+            var command = new RequestPlayListPictureUploadCommand(user.Id, "webp", "image/webp", ExpectedSizeBytes: 1_000_000);
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-        Assert.Empty(await Database.UploadIntents.ToListAsync(TestContext.Current.CancellationToken));
+            var result = await CreateHandler(config).Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+            Assert.Empty(await Database.UploadIntents.ToListAsync(TestContext.Current.CancellationToken));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListCommandHandlerTests.cs
index 0ebe7f2..683ed23 100644
--- a/backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListCommandHandlerTests.cs
@@ -6,75 +6,76 @@ using Musify.Application.Tests.TestSupport;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.PlayLists;
-
-public sealed class UpdatePlayListCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.PlayLists
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
-    private UpdatePlayListCommandHandler CreateHandler() => new(
-        eventBus,
-        Database,
-        new UploadIntentValidator(Database, storageService),
-        NoOpLogger<UpdatePlayListCommandHandler>(),
-        TestConfigurations.Storage(),
-        TestConfigurations.PlayList(),
-        TestConfigurations.UploadIntent());
-
-    [Fact]
-    public async Task Handle_Owner_RenamesPlayList()
+    public sealed class UpdatePlayListCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id, "Old Name");
-        await SeedAsync(owner, playList);
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
 
-        var command = new UpdatePlayListCommand(owner.Id, playList.Id, "New Name", null, null);
+        private UpdatePlayListCommandHandler CreateHandler() => new(
+            eventBus,
+            Database,
+            new UploadIntentValidator(Database, storageService),
+            NoOpLogger<UpdatePlayListCommandHandler>(),
+            TestConfigurations.Storage(),
+            TestConfigurations.PlayList(),
+            TestConfigurations.UploadIntent());
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_Owner_RenamesPlayList()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id, "Old Name");
+            await SeedAsync(owner, playList);
 
-        Assert.False(result.IsError);
-        Assert.Equal("New Name", result.Value.Name);
-    }
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "New Name", null, null);
 
-    [Fact]
-    public async Task Handle_PlayListMissing_ReturnsNotFound()
-    {
-        var command = new UpdatePlayListCommand(1, Guid.NewGuid(), "New Name", null, null);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("New Name", result.Value.Name);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var command = new UpdatePlayListCommand(1, Guid.NewGuid(), "New Name", null, null);
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var playList = TestEntities.PlayList(owner.Id);
-        await SeedAsync(owner, stranger, playList);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var command = new UpdatePlayListCommand(stranger.Id, playList.Id, "Hijacked", null, null);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+            var command = new UpdatePlayListCommand(stranger.Id, playList.Id, "Hijacked", null, null);
 
-    [Fact]
-    public async Task Handle_BlankNameAndDescription_LeavesThemUnchanged()
-    {
-        var owner = TestEntities.User();
-        var playList = TestEntities.PlayList(owner.Id, "Original Name", "Original description");
-        await SeedAsync(owner, playList);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var command = new UpdatePlayListCommand(owner.Id, playList.Id, "   ", "   ", null);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_BlankNameAndDescription_LeavesThemUnchanged()
+        {
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id, "Original Name", "Original description");
+            await SeedAsync(owner, playList);
 
-        Assert.False(result.IsError);
-        Assert.Equal("Original Name", result.Value.Name);
-        Assert.Equal("Original description", result.Value.Description);
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "   ", "   ", null);
+
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal("Original Name", result.Value.Name);
+            Assert.Equal("Original description", result.Value.Description);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Services/TrackStreamIssuerTests.cs b/backend/Tests/Musify.Application.Tests/Services/TrackStreamIssuerTests.cs
index e0ae6e8..91dd417 100644
--- a/backend/Tests/Musify.Application.Tests/Services/TrackStreamIssuerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Services/TrackStreamIssuerTests.cs
@@ -5,46 +5,47 @@ using Musify.Application.Tests.TestSupport;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Services;
-
-public sealed class TrackStreamIssuerTests : HandlerTestBase
+namespace Musify.Application.Tests.Services
 {
-    private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
-
-    private TrackStreamIssuer CreateIssuer() => new(
-        Database, ticketService, TestConfigurations.Track(), TestConfigurations.StreamGateway("https://stream.musify.test/"));
-
-    [Fact]
-    public async Task IssueAsync_BuildsManifestUrlAndRecordsListeningHistory()
+    public sealed class TrackStreamIssuerTests : HandlerTestBase
     {
-        ticketService.IssueTicket(7, Arg.Any<string>()).Returns(new StreamTicket("signed-token", 120));
-        var owner = TestEntities.User(7);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+        private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
 
-        var response = await CreateIssuer().IssueAsync(track.Id, "folder-42", userId: 7, TestContext.Current.CancellationToken);
+        private TrackStreamIssuer CreateIssuer() => new(
+            Database, ticketService, TestConfigurations.Track(), TestConfigurations.StreamGateway("https://stream.musify.test/"));
 
-        Assert.Equal("signed-token", response.Ticket);
-        Assert.Equal(120, response.ExpiresInSeconds);
-        Assert.Equal(
-            "https://stream.musify.test/media/Tracks/ProcessedAudios/folder-42/audio.m4a",
-            response.ManifestUrl);
+        [Fact]
+        public async Task IssueAsync_BuildsManifestUrlAndRecordsListeningHistory()
+        {
+            ticketService.IssueTicket(7, Arg.Any<string>()).Returns(new StreamTicket("signed-token", 120));
+            var owner = TestEntities.User(7);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
 
-        var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(7, history.UserId);
-        Assert.Equal(track.Id, history.TrackId);
-    }
+            var response = await CreateIssuer().IssueAsync(track.Id, "folder-42", userId: 7, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task IssueAsync_PassesTheProcessedAudioKeyPrefixToTheTicketService()
-    {
-        ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("token", 60));
-        var owner = TestEntities.User(1);
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+            Assert.Equal("signed-token", response.Ticket);
+            Assert.Equal(120, response.ExpiresInSeconds);
+            Assert.Equal(
+                "https://stream.musify.test/media/Tracks/ProcessedAudios/folder-42/audio.m4a",
+                response.ManifestUrl);
 
-        await CreateIssuer().IssueAsync(track.Id, "folder-42", userId: 1, TestContext.Current.CancellationToken);
+            var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(7, history.UserId);
+            Assert.Equal(track.Id, history.TrackId);
+        }
 
-        ticketService.Received(1).IssueTicket(1, "Tracks/ProcessedAudios/folder-42/");
+        [Fact]
+        public async Task IssueAsync_PassesTheProcessedAudioKeyPrefixToTheTicketService()
+        {
+            ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("token", 60));
+            var owner = TestEntities.User(1);
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
+
+            await CreateIssuer().IssueAsync(track.Id, "folder-42", userId: 1, TestContext.Current.CancellationToken);
+
+            ticketService.Received(1).IssueTicket(1, "Tracks/ProcessedAudios/folder-42/");
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Services/UploadIntentValidatorTests.cs b/backend/Tests/Musify.Application.Tests/Services/UploadIntentValidatorTests.cs
index e526555..441885b 100644
--- a/backend/Tests/Musify.Application.Tests/Services/UploadIntentValidatorTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Services/UploadIntentValidatorTests.cs
@@ -6,140 +6,141 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Services;
-
-public sealed class UploadIntentValidatorTests : HandlerTestBase
+namespace Musify.Application.Tests.Services
 {
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-    private readonly Domain.Entities.User owner = TestEntities.User();
-
-    private UploadIntentValidator CreateValidator() => new(Database, storageService);
-
-    [Fact]
-    public async Task ValidateAndLoadAsync_UploadedObjectWithinLimits_ReturnsTheIntent()
+    public sealed class UploadIntentValidatorTests : HandlerTestBase
     {
-        storageService
-            .HeadObjectAsync("bucket", "temp/object.webp", Arg.Any<CancellationToken>())
-            .Returns(new ObjectMetaData("image/webp", 2048));
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
+        private readonly Domain.Entities.User owner = TestEntities.User();
 
-        var intent = TestEntities.UploadIntent(owner.Id, bucket: "bucket", key: "temp/object.webp");
-        await SeedAsync(owner, intent);
+        private UploadIntentValidator CreateValidator() => new(Database, storageService);
 
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task ValidateAndLoadAsync_UploadedObjectWithinLimits_ReturnsTheIntent()
+        {
+            storageService
+                .HeadObjectAsync("bucket", "temp/object.webp", Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 2048));
 
-        Assert.False(result.IsError);
-        Assert.Equal(intent.Id, result.Value.Id);
-    }
+            var intent = TestEntities.UploadIntent(owner.Id, bucket: "bucket", key: "temp/object.webp");
+            await SeedAsync(owner, intent);
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_IntentMissing_ReturnsNotFound()
-    {
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), Guid.NewGuid(), owner.Id, TestContext.Current.CancellationToken);
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal(intent.Id, result.Value.Id);
+        }
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_IntentBelongsToAnotherUser_ReturnsNotFound()
-    {
-        var stranger = TestEntities.User(2, "stranger");
-        var intent = TestEntities.UploadIntent(owner.Id);
-        await SeedAsync(owner, stranger, intent);
+        [Fact]
+        public async Task ValidateAndLoadAsync_IntentMissing_ReturnsNotFound()
+        {
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), Guid.NewGuid(), owner.Id, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, stranger.Id, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task ValidateAndLoadAsync_IntentBelongsToAnotherUser_ReturnsNotFound()
+        {
+            var stranger = TestEntities.User(2, "stranger");
+            var intent = TestEntities.UploadIntent(owner.Id);
+            await SeedAsync(owner, stranger, intent);
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_AlreadyConsumed_ReturnsConflict()
-    {
-        var intent = TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Consumed);
-        await SeedAsync(owner, intent);
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, stranger.Id, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task ValidateAndLoadAsync_AlreadyConsumed_ReturnsConflict()
+        {
+            var intent = TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Consumed);
+            await SeedAsync(owner, intent);
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_PastExpiry_ReturnsValidationError()
-    {
-        var intent = TestEntities.UploadIntent(owner.Id, expiresAt: DateTime.UtcNow.AddMinutes(-1));
-        await SeedAsync(owner, intent);
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task ValidateAndLoadAsync_PastExpiry_ReturnsValidationError()
+        {
+            var intent = TestEntities.UploadIntent(owner.Id, expiresAt: DateTime.UtcNow.AddMinutes(-1));
+            await SeedAsync(owner, intent);
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_ObjectNeverUploaded_ReturnsNotFound()
-    {
-        storageService
-            .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns((ObjectMetaData?)null);
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
 
-        var intent = TestEntities.UploadIntent(owner.Id);
-        await SeedAsync(owner, intent);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+        }
 
-        var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task ValidateAndLoadAsync_ObjectNeverUploaded_ReturnsNotFound()
+        {
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns((ObjectMetaData?)null);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var intent = TestEntities.UploadIntent(owner.Id);
+            await SeedAsync(owner, intent);
 
-    [Fact]
-    public async Task ValidateAndLoadAsync_UploadedObjectExceedsMaxSize_ReturnsValidationError()
-    {
-        var config = TestConfigurations.UploadIntent();
-        config.MaxUploadBytes = 1024;
+            var result = await CreateValidator().ValidateAndLoadAsync(TestConfigurations.UploadIntent(), intent.Id, owner.Id, TestContext.Current.CancellationToken);
 
-        storageService
-            .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns(new ObjectMetaData("image/webp", 2048));
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var intent = TestEntities.UploadIntent(owner.Id);
-        await SeedAsync(owner, intent);
+        [Fact]
+        public async Task ValidateAndLoadAsync_UploadedObjectExceedsMaxSize_ReturnsValidationError()
+        {
+            var config = TestConfigurations.UploadIntent();
+            config.MaxUploadBytes = 1024;
 
-        var result = await CreateValidator().ValidateAndLoadAsync(config, intent.Id, owner.Id, TestContext.Current.CancellationToken);
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 2048));
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-    }
+            var intent = TestEntities.UploadIntent(owner.Id);
+            await SeedAsync(owner, intent);
 
-    [Fact]
-    public async Task CheckQuotaAsync_WithinLimits_ReturnsSuccess()
-    {
-        await SeedAsync(owner);
+            var result = await CreateValidator().ValidateAndLoadAsync(config, intent.Id, owner.Id, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().CheckQuotaAsync(TestConfigurations.UploadIntent(), owner.Id, requiredBytes: 1024, requiredIntentCount: 1, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+        }
 
-        Assert.False(result.IsError);
-    }
+        [Fact]
+        public async Task CheckQuotaAsync_WithinLimits_ReturnsSuccess()
+        {
+            await SeedAsync(owner);
 
-    [Fact]
-    public async Task CheckQuotaAsync_TooManyActiveIntents_ReturnsValidationError()
-    {
-        var config = TestConfigurations.UploadIntent();
-        config.MaxActiveUploadIntentsPerUser = 1;
-        await SeedAsync(owner, TestEntities.UploadIntent(owner.Id));
+            var result = await CreateValidator().CheckQuotaAsync(TestConfigurations.UploadIntent(), owner.Id, requiredBytes: 1024, requiredIntentCount: 1, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().CheckQuotaAsync(config, owner.Id, requiredBytes: 1, requiredIntentCount: 1, TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+        }
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task CheckQuotaAsync_TooManyActiveIntents_ReturnsValidationError()
+        {
+            var config = TestConfigurations.UploadIntent();
+            config.MaxActiveUploadIntentsPerUser = 1;
+            await SeedAsync(owner, TestEntities.UploadIntent(owner.Id));
 
-    [Fact]
-    public async Task CheckQuotaAsync_ExpiredOrConsumedIntentsDoNotCountTowardsTheLimit()
-    {
-        var config = TestConfigurations.UploadIntent();
-        config.MaxActiveUploadIntentsPerUser = 1;
-        await SeedAsync(
-            owner,
-            TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Expired),
-            TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Consumed));
+            var result = await CreateValidator().CheckQuotaAsync(config, owner.Id, requiredBytes: 1, requiredIntentCount: 1, TestContext.Current.CancellationToken);
 
-        var result = await CreateValidator().CheckQuotaAsync(config, owner.Id, requiredBytes: 1, requiredIntentCount: 1, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+        }
 
-        Assert.False(result.IsError);
+        [Fact]
+        public async Task CheckQuotaAsync_ExpiredOrConsumedIntentsDoNotCountTowardsTheLimit()
+        {
+            var config = TestConfigurations.UploadIntent();
+            config.MaxActiveUploadIntentsPerUser = 1;
+            await SeedAsync(
+                owner,
+                TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Expired),
+                TestEntities.UploadIntent(owner.Id, status: UploadIntentStatus.Consumed));
+
+            var result = await CreateValidator().CheckQuotaAsync(config, owner.Id, requiredBytes: 1, requiredIntentCount: 1, TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Services/YouTubeTrackProvisionerTests.cs b/backend/Tests/Musify.Application.Tests/Services/YouTubeTrackProvisionerTests.cs
index 09ffa6e..0613315 100644
--- a/backend/Tests/Musify.Application.Tests/Services/YouTubeTrackProvisionerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Services/YouTubeTrackProvisionerTests.cs
@@ -5,99 +5,100 @@ using Musify.Application.Tests.TestSupport;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Services;
-
-public sealed class YouTubeTrackProvisionerTests : HandlerTestBase
+namespace Musify.Application.Tests.Services
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private YouTubeTrackProvisioner CreateProvisioner() =>
-        new(Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
-
-    [Fact]
-    public async Task FindAsync_UnknownVideo_ReturnsNull()
+    public sealed class YouTubeTrackProvisionerTests : HandlerTestBase
     {
-        var track = await CreateProvisioner().FindAsync("missing-video", TestContext.Current.CancellationToken);
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        Assert.Null(track);
-    }
+        private YouTubeTrackProvisioner CreateProvisioner() =>
+            new(Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
 
-    [Fact]
-    public async Task GetOrCreateAsync_KnownVideo_ReturnsExistingTrackWithoutCallingTheService()
-    {
-        var existing = TestEntities.ExternalTrack(externalId: "known-video");
-        await SeedAsync(existing);
+        [Fact]
+        public async Task FindAsync_UnknownVideo_ReturnsNull()
+        {
+            var track = await CreateProvisioner().FindAsync("missing-video", TestContext.Current.CancellationToken);
 
-        var result = await CreateProvisioner().GetOrCreateAsync("known-video", TestContext.Current.CancellationToken);
+            Assert.Null(track);
+        }
 
-        Assert.False(result.IsError);
-        Assert.Equal(existing.Id, result.Value.Track.Id);
-        await youTubeMusicService.DidNotReceiveWithAnyArgs().GetSongAsync(default!, TestContext.Current.CancellationToken);
-    }
+        [Fact]
+        public async Task GetOrCreateAsync_KnownVideo_ReturnsExistingTrackWithoutCallingTheService()
+        {
+            var existing = TestEntities.ExternalTrack(externalId: "known-video");
+            await SeedAsync(existing);
 
-    [Fact]
-    public async Task GetOrCreateAsync_NewVideo_CreatesTrackAndDeduplicatesArtistsByName()
-    {
-        youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>()).Returns(
-            new YouTubeSongResult(
-                "new-video", "New Song", "New Artist", "Album", 210, "https://img/thumb.jpg", false,
-                [new YouTubeArtistRef(null, "New Artist"), new YouTubeArtistRef(null, "new artist")]));
+            var result = await CreateProvisioner().GetOrCreateAsync("known-video", TestContext.Current.CancellationToken);
 
-        var result = await CreateProvisioner().GetOrCreateAsync("new-video", TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal(existing.Id, result.Value.Track.Id);
+            await youTubeMusicService.DidNotReceiveWithAnyArgs().GetSongAsync(default!, TestContext.Current.CancellationToken);
+        }
 
-        Assert.False(result.IsError);
-        Assert.Equal("New Song", result.Value.Track.Title);
-        Assert.Single(await Database.Artists.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Single(await Database.TrackArtists.ToListAsync(TestContext.Current.CancellationToken));
-    }
+        [Fact]
+        public async Task GetOrCreateAsync_NewVideo_CreatesTrackAndDeduplicatesArtistsByName()
+        {
+            youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>()).Returns(
+                new YouTubeSongResult(
+                    "new-video", "New Song", "New Artist", "Album", 210, "https://img/thumb.jpg", false,
+                    [new YouTubeArtistRef(null, "New Artist"), new YouTubeArtistRef(null, "new artist")]));
 
-    [Fact]
-    public async Task GetOrCreateAsync_ServiceFails_ReturnsError()
-    {
-        youTubeMusicService.GetSongAsync("bad-video", Arg.Any<CancellationToken>())
-            .Returns(ErrorOr.Error.NotFound(description: "Video not found"));
+            var result = await CreateProvisioner().GetOrCreateAsync("new-video", TestContext.Current.CancellationToken);
 
-        var result = await CreateProvisioner().GetOrCreateAsync("bad-video", TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("New Song", result.Value.Track.Title);
+            Assert.Single(await Database.Artists.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Single(await Database.TrackArtists.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        Assert.True(result.IsError);
-    }
+        [Fact]
+        public async Task GetOrCreateAsync_ServiceFails_ReturnsError()
+        {
+            youTubeMusicService.GetSongAsync("bad-video", Arg.Any<CancellationToken>())
+                .Returns(ErrorOr.Error.NotFound(description: "Video not found"));
 
-    [Fact]
-    public async Task MaterializeAlbumAsync_NewAlbum_CreatesAlbumTracksAndLinks()
-    {
-        var detail = new YouTubeAlbumDetail(
-            new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false,
-                [new YouTubeArtistRef(null, "Album Artist")]),
-            Description: "desc",
-            TotalDurationSeconds: 400,
-            Tracks:
-            [
-                new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false),
-                new YouTubeAlbumTrack("track-2", "Track Two", 200, 2, false)
-            ]);
+            var result = await CreateProvisioner().GetOrCreateAsync("bad-video", TestContext.Current.CancellationToken);
 
-        await CreateProvisioner().MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
+            Assert.True(result.IsError);
+        }
 
-        Assert.Equal(2, await Database.ExternalTracks.CountAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(2, await Database.AlbumHasTracks.CountAsync(TestContext.Current.CancellationToken));
-        Assert.Single(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
-    }
+        [Fact]
+        public async Task MaterializeAlbumAsync_NewAlbum_CreatesAlbumTracksAndLinks()
+        {
+            var detail = new YouTubeAlbumDetail(
+                new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false,
+                    [new YouTubeArtistRef(null, "Album Artist")]),
+                Description: "desc",
+                TotalDurationSeconds: 400,
+                Tracks:
+                [
+                    new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false),
+                    new YouTubeAlbumTrack("track-2", "Track Two", 200, 2, false)
+                ]);
 
-    [Fact]
-    public async Task MaterializeAlbumAsync_CalledTwice_DoesNotDuplicateTracksOrLinks()
-    {
-        var detail = new YouTubeAlbumDetail(
-            new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false, []),
-            Description: "desc",
-            TotalDurationSeconds: 200,
-            Tracks: [new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false)]);
+            await CreateProvisioner().MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
 
-        var provisioner = CreateProvisioner();
-        await provisioner.MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
-        await provisioner.MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
+            Assert.Equal(2, await Database.ExternalTracks.CountAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(2, await Database.AlbumHasTracks.CountAsync(TestContext.Current.CancellationToken));
+            Assert.Single(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        Assert.Single(await Database.ExternalTracks.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Single(await Database.AlbumHasTracks.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Single(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
+        [Fact]
+        public async Task MaterializeAlbumAsync_CalledTwice_DoesNotDuplicateTracksOrLinks()
+        {
+            var detail = new YouTubeAlbumDetail(
+                new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false, []),
+                Description: "desc",
+                TotalDurationSeconds: 200,
+                Tracks: [new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false)]);
+
+            var provisioner = CreateProvisioner();
+            await provisioner.MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
+            await provisioner.MaterializeAlbumAsync("album-1", detail, TestContext.Current.CancellationToken);
+
+            Assert.Single(await Database.ExternalTracks.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Single(await Database.AlbumHasTracks.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Single(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Shared/StorageKeyTests.cs b/backend/Tests/Musify.Application.Tests/Shared/StorageKeyTests.cs
index 8311815..447256b 100644
--- a/backend/Tests/Musify.Application.Tests/Shared/StorageKeyTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Shared/StorageKeyTests.cs
@@ -1,40 +1,41 @@
 using Musify.Application.Shared;
 using Xunit;
 
-namespace Musify.Application.Tests.Shared;
-
-public sealed class StorageKeyTests
+namespace Musify.Application.Tests.Shared
 {
-    [Fact]
-    public void Combine_MultipleSegments_JoinsThemWithForwardSlashes()
+    public sealed class StorageKeyTests
     {
-        var key = StorageKey.Combine("Tracks", "SmallPictures", "cover.webp");
+        [Fact]
+        public void Combine_MultipleSegments_JoinsThemWithForwardSlashes()
+        {
+            var key = StorageKey.Combine("Tracks", "SmallPictures", "cover.webp");
 
-        Assert.Equal("Tracks/SmallPictures/cover.webp", key);
-    }
+            Assert.Equal("Tracks/SmallPictures/cover.webp", key);
+        }
 
-    [Fact]
-    public void Combine_SegmentsWithSurroundingSlashesAndWhitespace_TrimsThem()
-    {
-        var key = StorageKey.Combine(" Tracks/ ", "/SmallPictures/", "cover.webp");
+        [Fact]
+        public void Combine_SegmentsWithSurroundingSlashesAndWhitespace_TrimsThem()
+        {
+            var key = StorageKey.Combine(" Tracks/ ", "/SmallPictures/", "cover.webp");
 
-        Assert.Equal("Tracks/SmallPictures/cover.webp", key);
-    }
+            Assert.Equal("Tracks/SmallPictures/cover.webp", key);
+        }
 
-    [Theory]
-    [InlineData(null)]
-    [InlineData("")]
-    [InlineData("   ")]
-    public void Combine_BlankSegment_IsSkipped(string? blank)
-    {
-        var key = StorageKey.Combine("Tracks", blank!, "cover.webp");
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("   ")]
+        public void Combine_BlankSegment_IsSkipped(string? blank)
+        {
+            var key = StorageKey.Combine("Tracks", blank!, "cover.webp");
 
-        Assert.Equal("Tracks/cover.webp", key);
-    }
+            Assert.Equal("Tracks/cover.webp", key);
+        }
 
-    [Fact]
-    public void Combine_NoSegments_ReturnsEmptyString()
-    {
-        Assert.Equal(string.Empty, StorageKey.Combine());
+        [Fact]
+        public void Combine_NoSegments_ReturnsEmptyString()
+        {
+            Assert.Equal(string.Empty, StorageKey.Combine());
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Shared/TrackApplicationResponseTests.cs b/backend/Tests/Musify.Application.Tests/Shared/TrackApplicationResponseTests.cs
index 6006c81..151137d 100644
--- a/backend/Tests/Musify.Application.Tests/Shared/TrackApplicationResponseTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Shared/TrackApplicationResponseTests.cs
@@ -4,49 +4,50 @@ using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
 using Xunit;
 
-namespace Musify.Application.Tests.Shared;
-
-public sealed class TrackApplicationResponseTests
+namespace Musify.Application.Tests.Shared
 {
-    [Fact]
-    public void FromEntity_LocalTrack_UsesOwnerNameAsArtist()
+    public sealed class TrackApplicationResponseTests
     {
-        var owner = TestEntities.User(1, "The Owner");
-        var track = TestEntities.LocalTrack(owner);
+        [Fact]
+        public void FromEntity_LocalTrack_UsesOwnerNameAsArtist()
+        {
+            var owner = TestEntities.User(1, "The Owner");
+            var track = TestEntities.LocalTrack(owner);
 
-        var response = TrackApplicationResponse.FromEntity(track, listensCount: 3);
+            var response = TrackApplicationResponse.FromEntity(track, listensCount: 3);
 
-        Assert.Equal("The Owner", response.Artist);
-        Assert.Equal(TrackSource.Local, response.Source);
-        Assert.Equal(owner.Id, response.OwnerUserId);
-        Assert.Equal(3, response.ListensCount);
-    }
+            Assert.Equal("The Owner", response.Artist);
+            Assert.Equal(TrackSource.Local, response.Source);
+            Assert.Equal(owner.Id, response.OwnerUserId);
+            Assert.Equal(3, response.ListensCount);
+        }
 
-    [Fact]
-    public void FromEntity_ExternalTrackWithArtists_JoinsThemInPositionOrder()
-    {
-        var track = TestEntities.ExternalTrack();
-        var second = new Artist { Name = "Second Artist", NormalizedName = "SECOND ARTIST", ExternalId = "second" };
-        var first = new Artist { Name = "First Artist", NormalizedName = "FIRST ARTIST", ExternalId = "first" };
-        track.TrackArtists =
-        [
-            new TrackArtist { TrackId = track.Id, ArtistId = second.Id, Position = 1, Artist = second, Track = track },
-            new TrackArtist { TrackId = track.Id, ArtistId = first.Id, Position = 0, Artist = first, Track = track }
-        ];
+        [Fact]
+        public void FromEntity_ExternalTrackWithArtists_JoinsThemInPositionOrder()
+        {
+            var track = TestEntities.ExternalTrack();
+            var second = new Artist { Name = "Second Artist", NormalizedName = "SECOND ARTIST", ExternalId = "second" };
+            var first = new Artist { Name = "First Artist", NormalizedName = "FIRST ARTIST", ExternalId = "first" };
+            track.TrackArtists =
+            [
+                new TrackArtist { TrackId = track.Id, ArtistId = second.Id, Position = 1, Artist = second, Track = track },
+                new TrackArtist { TrackId = track.Id, ArtistId = first.Id, Position = 0, Artist = first, Track = track }
+            ];
 
-        var response = TrackApplicationResponse.FromEntity(track, listensCount: 0);
+            var response = TrackApplicationResponse.FromEntity(track, listensCount: 0);
 
-        Assert.Equal("First Artist, Second Artist", response.Artist);
-        Assert.Equal(track.ExternalId, response.ExternalId);
-    }
+            Assert.Equal("First Artist, Second Artist", response.Artist);
+            Assert.Equal(track.ExternalId, response.ExternalId);
+        }
 
-    [Fact]
-    public void FromEntity_ExternalTrackWithNoArtists_HasNullArtist()
-    {
-        var track = TestEntities.ExternalTrack();
+        [Fact]
+        public void FromEntity_ExternalTrackWithNoArtists_HasNullArtist()
+        {
+            var track = TestEntities.ExternalTrack();
 
-        var response = TrackApplicationResponse.FromEntity(track, listensCount: 0);
+            var response = TrackApplicationResponse.FromEntity(track, listensCount: 0);
 
-        Assert.Null(response.Artist);
+            Assert.Null(response.Artist);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/TestSupport/HandlerTestBase.cs b/backend/Tests/Musify.Application.Tests/TestSupport/HandlerTestBase.cs
index 1a2269d..4752509 100644
--- a/backend/Tests/Musify.Application.Tests/TestSupport/HandlerTestBase.cs
+++ b/backend/Tests/Musify.Application.Tests/TestSupport/HandlerTestBase.cs
@@ -2,32 +2,33 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using Xunit;
 
-namespace Musify.Application.Tests.TestSupport;
-
-/// <summary>
-/// Base class for handler tests: gives every test method its own empty, isolated
-/// <see cref="TestDatabase"/> (xUnit creates a new instance of the test class per test method,
-/// so there is no state to reset between tests) and a no-op logger factory for handlers that
-/// take an <see cref="ILogger{TCategoryName}"/>.
-/// </summary>
-public abstract class HandlerTestBase : IAsyncLifetime
+namespace Musify.Application.Tests.TestSupport
 {
-    private TestDatabase database = null!;
-
-    protected TestDatabase Database => database;
-
-    public async ValueTask InitializeAsync() => database = await TestDatabase.CreateAsync();
-
-    public ValueTask DisposeAsync() => database.DisposeAsync();
-
-    protected static ILogger<T> NoOpLogger<T>() => NullLogger<T>.Instance;
-
-    /// <summary>Adds the entities and persists them, so handlers under test see committed data.</summary>
-    protected async Task SeedAsync(params object[] entities)
+    /// <summary>
+    /// Base class for handler tests: gives every test method its own empty, isolated
+    /// <see cref="TestDatabase"/> (xUnit creates a new instance of the test class per test method,
+    /// so there is no state to reset between tests) and a no-op logger factory for handlers that
+    /// take an <see cref="ILogger{TCategoryName}"/>.
+    /// </summary>
+    public abstract class HandlerTestBase : IAsyncLifetime
     {
-        foreach (var entity in entities)
-            Database.Add(entity);
+        private TestDatabase database = null!;
 
-        await Database.SaveChangesAsync(CancellationToken.None);
+        protected TestDatabase Database => database;
+
+        public async ValueTask InitializeAsync() => database = await TestDatabase.CreateAsync();
+
+        public ValueTask DisposeAsync() => database.DisposeAsync();
+
+        protected static ILogger<T> NoOpLogger<T>() => NullLogger<T>.Instance;
+
+        /// <summary>Adds the entities and persists them, so handlers under test see committed data.</summary>
+        protected async Task SeedAsync(params object[] entities)
+        {
+            foreach (var entity in entities)
+                Database.Add(entity);
+
+            await Database.SaveChangesAsync(CancellationToken.None);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/TestSupport/TestConfigurations.cs b/backend/Tests/Musify.Application.Tests/TestSupport/TestConfigurations.cs
index cec69a8..6b401b6 100644
--- a/backend/Tests/Musify.Application.Tests/TestSupport/TestConfigurations.cs
+++ b/backend/Tests/Musify.Application.Tests/TestSupport/TestConfigurations.cs
@@ -1,24 +1,25 @@
 using Musify.Application.Configuration;
 
-namespace Musify.Application.Tests.TestSupport;
-
-/// <summary>
-/// Configuration POCOs with every <c>required</c> member filled and the rest left at their
-/// production defaults, so handler tests don't have to know which fields matter for them.
-/// </summary>
-public static class TestConfigurations
+namespace Musify.Application.Tests.TestSupport
 {
-    public static ApplicationStorageConfiguration Storage(string bucket = "test-bucket") =>
-        new() { Bucket = bucket };
+    /// <summary>
+    /// Configuration POCOs with every <c>required</c> member filled and the rest left at their
+    /// production defaults, so handler tests don't have to know which fields matter for them.
+    /// </summary>
+    public static class TestConfigurations
+    {
+        public static ApplicationStorageConfiguration Storage(string bucket = "test-bucket") =>
+            new() { Bucket = bucket };
 
-    public static TrackConfiguration Track() => new();
+        public static TrackConfiguration Track() => new();
 
-    public static PlayListConfiguration PlayList() => new();
+        public static PlayListConfiguration PlayList() => new();
 
-    public static MixConfiguration Mix() => new();
+        public static MixConfiguration Mix() => new();
 
-    public static UploadIntentConfiguration UploadIntent() => new();
+        public static UploadIntentConfiguration UploadIntent() => new();
 
-    public static StreamGatewayConfiguration StreamGateway(string publicBaseUrl = "https://stream.musify.test") =>
-        new() { PublicBaseUrl = publicBaseUrl };
+        public static StreamGatewayConfiguration StreamGateway(string publicBaseUrl = "https://stream.musify.test") =>
+            new() { PublicBaseUrl = publicBaseUrl };
+    }
 }
diff --git a/backend/Tests/Musify.Application.Tests/TestSupport/TestDatabase.cs b/backend/Tests/Musify.Application.Tests/TestSupport/TestDatabase.cs
index 5e46523..b2a913d 100644
--- a/backend/Tests/Musify.Application.Tests/TestSupport/TestDatabase.cs
+++ b/backend/Tests/Musify.Application.Tests/TestSupport/TestDatabase.cs
@@ -3,209 +3,210 @@ using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Domain.Entities;
 
-namespace Musify.Application.Tests.TestSupport;
-
-/// <summary>
-/// An <see cref="IDatabase"/> backed by a private, in-memory SQLite database.
-/// </summary>
-/// <remarks>
-/// <para>
-/// <see cref="IDatabase"/> exposes raw <see cref="DbSet{TEntity}"/> properties, so handlers
-/// compose real LINQ queries (<c>Where</c>, <c>Select</c>, <c>Include</c>, ...) against it.
-/// Substituting <see cref="IDatabase"/> with a mock cannot express that — there is no
-/// <see cref="IQueryable{T}"/> provider behind a mock. SQLite's in-memory mode gives us a real
-/// relational engine instead: fast, no external dependency, and — unlike the EF Core InMemory
-/// provider — it actually supports transactions, which two handlers rely on.
-/// </para>
-/// <para>
-/// The model mirrors the parts of <c>Musify.Infrastructure.Persistence.Database</c> that affect
-/// query shape (owned types, table-per-type inheritance, unique indexes). MassTransit outbox/saga
-/// state and Postgres-specific configuration are left out — the Application layer never touches
-/// them.
-/// </para>
-/// </remarks>
-public sealed class TestDatabase : DbContext, IDatabase
+namespace Musify.Application.Tests.TestSupport
 {
-    private readonly SqliteConnection connection;
-
-    private TestDatabase(SqliteConnection connection, DbContextOptions<TestDatabase> options)
-        : base(options)
-    {
-        this.connection = connection;
-    }
-
     /// <summary>
-    /// Creates a fresh, empty database with its own private connection. Call <see cref="Seed"/>
-    /// (via <see cref="Seeding.EntitySeedExtensions"/>) to populate it, then <see cref="DisposeAsync"/>
-    /// when the test is done.
+    /// An <see cref="IDatabase"/> backed by a private, in-memory SQLite database.
     /// </summary>
-    public static async Task<TestDatabase> CreateAsync()
+    /// <remarks>
+    /// <para>
+    /// <see cref="IDatabase"/> exposes raw <see cref="DbSet{TEntity}"/> properties, so handlers
+    /// compose real LINQ queries (<c>Where</c>, <c>Select</c>, <c>Include</c>, ...) against it.
+    /// Substituting <see cref="IDatabase"/> with a mock cannot express that — there is no
+    /// <see cref="IQueryable{T}"/> provider behind a mock. SQLite's in-memory mode gives us a real
+    /// relational engine instead: fast, no external dependency, and — unlike the EF Core InMemory
+    /// provider — it actually supports transactions, which two handlers rely on.
+    /// </para>
+    /// <para>
+    /// The model mirrors the parts of <c>Musify.Infrastructure.Persistence.Database</c> that affect
+    /// query shape (owned types, table-per-type inheritance, unique indexes). MassTransit outbox/saga
+    /// state and Postgres-specific configuration are left out — the Application layer never touches
+    /// them.
+    /// </para>
+    /// </remarks>
+    public sealed class TestDatabase : DbContext, IDatabase
     {
-        var connection = new SqliteConnection("Filename=:memory:");
-        await connection.OpenAsync();
+        private readonly SqliteConnection connection;
 
-        var options = new DbContextOptionsBuilder<TestDatabase>()
-            .UseSqlite(connection)
-            .Options;
+        private TestDatabase(SqliteConnection connection, DbContextOptions<TestDatabase> options)
+            : base(options)
+        {
+            this.connection = connection;
+        }
 
-        var database = new TestDatabase(connection, options);
-        await database.Database.EnsureCreatedAsync();
-        return database;
-    }
+        /// <summary>
+        /// Creates a fresh, empty database with its own private connection. Call <see cref="Seed"/>
+        /// (via <see cref="Seeding.EntitySeedExtensions"/>) to populate it, then <see cref="DisposeAsync"/>
+        /// when the test is done.
+        /// </summary>
+        public static async Task<TestDatabase> CreateAsync()
+        {
+            var connection = new SqliteConnection("Filename=:memory:");
+            await connection.OpenAsync();
 
-    protected override void OnModelCreating(ModelBuilder modelBuilder)
-    {
-        base.OnModelCreating(modelBuilder);
+            var options = new DbContextOptionsBuilder<TestDatabase>()
+                .UseSqlite(connection)
+                .Options;
 
-        modelBuilder.Entity<Track>().OwnsOne(track => track.Pictures);
-        modelBuilder.Entity<Track>().Navigation(track => track.Pictures).IsRequired();
+            var database = new TestDatabase(connection, options);
+            await database.Database.EnsureCreatedAsync();
+            return database;
+        }
 
-        modelBuilder.Entity<Track>().OwnsOne(track => track.Audio);
-        modelBuilder.Entity<Track>().Navigation(track => track.Audio).IsRequired();
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            base.OnModelCreating(modelBuilder);
 
-        modelBuilder.Entity<LocalTrack>().ToTable("LocalTracks");
+            modelBuilder.Entity<Track>().OwnsOne(track => track.Pictures);
+            modelBuilder.Entity<Track>().Navigation(track => track.Pictures).IsRequired();
 
-        modelBuilder.Entity<LocalTrack>()
-            .HasOne(track => track.Owner)
-            .WithMany()
-            .HasForeignKey(track => track.OwnerUserId)
-            .OnDelete(DeleteBehavior.Restrict);
+            modelBuilder.Entity<Track>().OwnsOne(track => track.Audio);
+            modelBuilder.Entity<Track>().Navigation(track => track.Audio).IsRequired();
 
-        modelBuilder.Entity<ExternalTrack>().ToTable("ExternalTracks");
+            modelBuilder.Entity<LocalTrack>().ToTable("LocalTracks");
 
-        modelBuilder.Entity<ExternalTrack>()
-            .HasIndex(track => new { track.Source, track.ExternalId })
-            .IsUnique();
+            modelBuilder.Entity<LocalTrack>()
+                .HasOne(track => track.Owner)
+                .WithMany()
+                .HasForeignKey(track => track.OwnerUserId)
+                .OnDelete(DeleteBehavior.Restrict);
 
-        modelBuilder.Entity<TrackArtist>()
-            .HasKey(trackArtist => new { trackArtist.TrackId, trackArtist.ArtistId });
+            modelBuilder.Entity<ExternalTrack>().ToTable("ExternalTracks");
 
-        modelBuilder.Entity<TrackArtist>()
-            .HasOne(trackArtist => trackArtist.Track)
-            .WithMany(track => track.TrackArtists)
-            .HasForeignKey(trackArtist => trackArtist.TrackId)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<ExternalTrack>()
+                .HasIndex(track => new { track.Source, track.ExternalId })
+                .IsUnique();
 
-        modelBuilder.Entity<TrackArtist>()
-            .HasOne(trackArtist => trackArtist.Artist)
-            .WithMany(artist => artist.TrackArtists)
-            .HasForeignKey(trackArtist => trackArtist.ArtistId)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<TrackArtist>()
+                .HasKey(trackArtist => new { trackArtist.TrackId, trackArtist.ArtistId });
 
-        modelBuilder.Entity<Artist>()
-            .HasIndex(artist => artist.ExternalId)
-            .IsUnique();
+            modelBuilder.Entity<TrackArtist>()
+                .HasOne(trackArtist => trackArtist.Track)
+                .WithMany(track => track.TrackArtists)
+                .HasForeignKey(trackArtist => trackArtist.TrackId)
+                .OnDelete(DeleteBehavior.Cascade);
 
-        modelBuilder.Entity<PlayList>().OwnsOne(playList => playList.Pictures);
-        modelBuilder.Entity<PlayList>().Navigation(playList => playList.Pictures).IsRequired();
+            modelBuilder.Entity<TrackArtist>()
+                .HasOne(trackArtist => trackArtist.Artist)
+                .WithMany(artist => artist.TrackArtists)
+                .HasForeignKey(trackArtist => trackArtist.ArtistId)
+                .OnDelete(DeleteBehavior.Cascade);
 
-        modelBuilder.Entity<Album>().OwnsOne(album => album.Pictures);
-        modelBuilder.Entity<Album>().Navigation(album => album.Pictures).IsRequired(false);
+            modelBuilder.Entity<Artist>()
+                .HasIndex(artist => artist.ExternalId)
+                .IsUnique();
 
-        modelBuilder.Entity<UserAlbum>().ToTable("UserAlbums");
+            modelBuilder.Entity<PlayList>().OwnsOne(playList => playList.Pictures);
+            modelBuilder.Entity<PlayList>().Navigation(playList => playList.Pictures).IsRequired();
 
-        modelBuilder.Entity<UserAlbum>()
-            .HasOne(album => album.Owner)
-            .WithMany()
-            .HasForeignKey(album => album.OwnerUserId)
-            .OnDelete(DeleteBehavior.Restrict);
+            modelBuilder.Entity<Album>().OwnsOne(album => album.Pictures);
+            modelBuilder.Entity<Album>().Navigation(album => album.Pictures).IsRequired(false);
 
-        modelBuilder.Entity<ExternalAlbum>().ToTable("ExternalAlbums");
+            modelBuilder.Entity<UserAlbum>().ToTable("UserAlbums");
 
-        modelBuilder.Entity<ExternalAlbum>()
-            .HasIndex(album => new { album.Source, album.ExternalId })
-            .IsUnique();
+            modelBuilder.Entity<UserAlbum>()
+                .HasOne(album => album.Owner)
+                .WithMany()
+                .HasForeignKey(album => album.OwnerUserId)
+                .OnDelete(DeleteBehavior.Restrict);
 
-        modelBuilder.Entity<AlbumHasTrack>()
-            .HasOne(albumTrack => albumTrack.Album)
-            .WithMany(album => album.AlbumTracks)
-            .HasForeignKey(albumTrack => albumTrack.AlbumId)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<ExternalAlbum>().ToTable("ExternalAlbums");
 
-        modelBuilder.Entity<AlbumHasTrack>()
-            .HasOne(albumTrack => albumTrack.Track)
-            .WithMany(track => track.AlbumTracks)
-            .HasForeignKey(albumTrack => albumTrack.TrackId)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<ExternalAlbum>()
+                .HasIndex(album => new { album.Source, album.ExternalId })
+                .IsUnique();
 
-        modelBuilder.Entity<AlbumHasTrack>()
-            .HasIndex(albumTrack => new { albumTrack.AlbumId, albumTrack.TrackId })
-            .IsUnique();
+            modelBuilder.Entity<AlbumHasTrack>()
+                .HasOne(albumTrack => albumTrack.Album)
+                .WithMany(album => album.AlbumTracks)
+                .HasForeignKey(albumTrack => albumTrack.AlbumId)
+                .OnDelete(DeleteBehavior.Cascade);
 
-        modelBuilder.Entity<Mix>()
-            .HasIndex(mix => new { mix.UserId, mix.Position });
+            modelBuilder.Entity<AlbumHasTrack>()
+                .HasOne(albumTrack => albumTrack.Track)
+                .WithMany(track => track.AlbumTracks)
+                .HasForeignKey(albumTrack => albumTrack.TrackId)
+                .OnDelete(DeleteBehavior.Cascade);
 
-        modelBuilder.Entity<MixItem>()
-            .HasOne(item => item.Mix)
-            .WithMany(mix => mix.Items)
-            .HasForeignKey(item => item.MixId)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<AlbumHasTrack>()
+                .HasIndex(albumTrack => new { albumTrack.AlbumId, albumTrack.TrackId })
+                .IsUnique();
 
-        modelBuilder.Entity<MixItem>()
-            .HasOne(item => item.Track)
-            .WithMany()
-            .HasForeignKey(item => item.TrackId)
-            .IsRequired(false)
-            .OnDelete(DeleteBehavior.Cascade);
+            modelBuilder.Entity<Mix>()
+                .HasIndex(mix => new { mix.UserId, mix.Position });
 
-        modelBuilder.Entity<MixItem>()
-            .HasIndex(item => new { item.MixId, item.Position });
-    }
+            modelBuilder.Entity<MixItem>()
+                .HasOne(item => item.Mix)
+                .WithMany(mix => mix.Items)
+                .HasForeignKey(item => item.MixId)
+                .OnDelete(DeleteBehavior.Cascade);
 
-    public DbSet<User> Users => Set<User>();
+            modelBuilder.Entity<MixItem>()
+                .HasOne(item => item.Track)
+                .WithMany()
+                .HasForeignKey(item => item.TrackId)
+                .IsRequired(false)
+                .OnDelete(DeleteBehavior.Cascade);
 
-    public DbSet<PlayList> PlayLists => Set<PlayList>();
+            modelBuilder.Entity<MixItem>()
+                .HasIndex(item => new { item.MixId, item.Position });
+        }
 
-    public DbSet<Album> Albums => Set<Album>();
+        public DbSet<User> Users => Set<User>();
 
-    public DbSet<UserAlbum> UserAlbums => Set<UserAlbum>();
+        public DbSet<PlayList> PlayLists => Set<PlayList>();
 
-    public DbSet<ExternalAlbum> ExternalAlbums => Set<ExternalAlbum>();
+        public DbSet<Album> Albums => Set<Album>();
 
-    public DbSet<AlbumHasTrack> AlbumHasTracks => Set<AlbumHasTrack>();
+        public DbSet<UserAlbum> UserAlbums => Set<UserAlbum>();
 
-    public DbSet<Track> Tracks => Set<Track>();
+        public DbSet<ExternalAlbum> ExternalAlbums => Set<ExternalAlbum>();
 
-    public DbSet<LocalTrack> LocalTracks => Set<LocalTrack>();
+        public DbSet<AlbumHasTrack> AlbumHasTracks => Set<AlbumHasTrack>();
 
-    public DbSet<ExternalTrack> ExternalTracks => Set<ExternalTrack>();
+        public DbSet<Track> Tracks => Set<Track>();
 
-    public DbSet<Artist> Artists => Set<Artist>();
+        public DbSet<LocalTrack> LocalTracks => Set<LocalTrack>();
 
-    public DbSet<TrackArtist> TrackArtists => Set<TrackArtist>();
+        public DbSet<ExternalTrack> ExternalTracks => Set<ExternalTrack>();
 
-    public DbSet<UserHasTrack> UserHasTracks => Set<UserHasTrack>();
+        public DbSet<Artist> Artists => Set<Artist>();
 
-    public DbSet<PlayListHasTrack> PlayListHasTracks => Set<PlayListHasTrack>();
+        public DbSet<TrackArtist> TrackArtists => Set<TrackArtist>();
 
-    public DbSet<Mix> Mixes => Set<Mix>();
+        public DbSet<UserHasTrack> UserHasTracks => Set<UserHasTrack>();
 
-    public DbSet<MixItem> MixItems => Set<MixItem>();
+        public DbSet<PlayListHasTrack> PlayListHasTracks => Set<PlayListHasTrack>();
 
-    public DbSet<Upload> Uploads => Set<Upload>();
+        public DbSet<Mix> Mixes => Set<Mix>();
 
-    public DbSet<UploadIntent> UploadIntents => Set<UploadIntent>();
+        public DbSet<MixItem> MixItems => Set<MixItem>();
 
-    public DbSet<ListeningHistory> ListeningHistories => Set<ListeningHistory>();
+        public DbSet<Upload> Uploads => Set<Upload>();
 
-    public async Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken)
-    {
-        var transaction = await Database.BeginTransactionAsync(isolationLevel, cancellationToken);
-        return new SqliteDatabaseTransaction(transaction);
-    }
+        public DbSet<UploadIntent> UploadIntents => Set<UploadIntent>();
 
-    public override async ValueTask DisposeAsync()
-    {
-        await base.DisposeAsync();
-        await connection.DisposeAsync();
-    }
+        public DbSet<ListeningHistory> ListeningHistories => Set<ListeningHistory>();
 
-    private sealed class SqliteDatabaseTransaction(Microsoft.EntityFrameworkCore.Storage.IDbContextTransaction inner)
-        : IDatabaseTransaction
-    {
-        public Task CommitAsync(CancellationToken cancellationToken = default) =>
-            inner.CommitAsync(cancellationToken);
+        public async Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken)
+        {
+            var transaction = await Database.BeginTransactionAsync(isolationLevel, cancellationToken);
+            return new SqliteDatabaseTransaction(transaction);
+        }
 
-        public ValueTask DisposeAsync() => inner.DisposeAsync();
+        public override async ValueTask DisposeAsync()
+        {
+            await base.DisposeAsync();
+            await connection.DisposeAsync();
+        }
+
+        private sealed class SqliteDatabaseTransaction(Microsoft.EntityFrameworkCore.Storage.IDbContextTransaction inner)
+            : IDatabaseTransaction
+        {
+            public Task CommitAsync(CancellationToken cancellationToken = default) =>
+                inner.CommitAsync(cancellationToken);
+
+            public ValueTask DisposeAsync() => inner.DisposeAsync();
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/TestSupport/TestEntities.cs b/backend/Tests/Musify.Application.Tests/TestSupport/TestEntities.cs
index 94dab2e..ca3556f 100644
--- a/backend/Tests/Musify.Application.Tests/TestSupport/TestEntities.cs
+++ b/backend/Tests/Musify.Application.Tests/TestSupport/TestEntities.cs
@@ -1,237 +1,238 @@
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.Tests.TestSupport;
-
-/// <summary>
-/// Builds fully-populated domain entities for tests, with sensible defaults for every
-/// <c>required</c> member. Every factory always returns a valid instance — never null — so
-/// callers never need a null check on what this class hands back.
-/// </summary>
-public static class TestEntities
+namespace Musify.Application.Tests.TestSupport
 {
-    public static User User(
-        long id = 1,
-        string name = "test-user",
-        string? firstName = "Test",
-        string? secondName = "User",
-        string? profilePictureUrl = null) =>
-        new()
-        {
-            Id = id,
-            Name = name,
-            NormalizedName = name.ToUpperInvariant(),
-            FirstName = firstName,
-            SecondName = secondName,
-            ProfilePictureUrl = profilePictureUrl
-        };
-
-    public static TrackPictures ProcessedPictures() => new()
+    /// <summary>
+    /// Builds fully-populated domain entities for tests, with sensible defaults for every
+    /// <c>required</c> member. Every factory always returns a valid instance — never null — so
+    /// callers never need a null check on what this class hands back.
+    /// </summary>
+    public static class TestEntities
     {
-        OriginalName = "original.webp",
-        SmallName = "small.webp",
-        MediumName = "medium.webp",
-        LargeName = "large.webp",
-        ProcessingStatus = ProcessingStatus.Completed
-    };
+        public static User User(
+            long id = 1,
+            string name = "test-user",
+            string? firstName = "Test",
+            string? secondName = "User",
+            string? profilePictureUrl = null) =>
+            new()
+            {
+                Id = id,
+                Name = name,
+                NormalizedName = name.ToUpperInvariant(),
+                FirstName = firstName,
+                SecondName = secondName,
+                ProfilePictureUrl = profilePictureUrl
+            };
 
-    public static TrackPictures PendingPictures() => new()
-    {
-        OriginalName = "original.webp",
-        ProcessingStatus = ProcessingStatus.Pending
-    };
-
-    public static TrackAudio ProcessedAudio(string folderName = "audio-folder") => new()
-    {
-        OriginalName = "original.mp3",
-        FolderName = folderName,
-        TranscodeStatus = ProcessingStatus.Completed
-    };
-
-    public static TrackAudio PendingAudio() => new()
-    {
-        OriginalName = "original.mp3",
-        TranscodeStatus = ProcessingStatus.Pending
-    };
-
-    public static LocalTrack LocalTrack(
-        User owner,
-        string title = "Test Track",
-        double durationSeconds = 180,
-        TrackPictures? pictures = null,
-        TrackAudio? audio = null,
-        LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
-        new()
+        public static TrackPictures ProcessedPictures() => new()
         {
-            Title = title,
-            NormalizedTitle = title.ToUpperInvariant(),
-            DurationSeconds = durationSeconds,
-            LifeCycleStatus = lifeCycleStatus,
-            OwnerUserId = owner.Id,
-            Owner = owner,
-            Pictures = pictures ?? ProcessedPictures(),
-            Audio = audio ?? ProcessedAudio()
+            OriginalName = "original.webp",
+            SmallName = "small.webp",
+            MediumName = "medium.webp",
+            LargeName = "large.webp",
+            ProcessingStatus = ProcessingStatus.Completed
         };
 
-    public static ExternalTrack ExternalTrack(
-        string externalId = "video-id",
-        string title = "Test External Track",
-        double durationSeconds = 180,
-        TrackSource source = TrackSource.YouTube,
-        TrackPictures? pictures = null,
-        TrackAudio? audio = null,
-        LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
-        new()
+        public static TrackPictures PendingPictures() => new()
         {
-            Title = title,
-            NormalizedTitle = title.ToUpperInvariant(),
-            DurationSeconds = durationSeconds,
-            LifeCycleStatus = lifeCycleStatus,
-            Source = source,
-            ExternalId = externalId,
-            Pictures = pictures ?? ProcessedPictures(),
-            Audio = audio ?? ProcessedAudio()
+            OriginalName = "original.webp",
+            ProcessingStatus = ProcessingStatus.Pending
         };
 
-    public static Artist Artist(
-        string name = "Test Artist",
-        string externalId = "artist-id") =>
-        new()
+        public static TrackAudio ProcessedAudio(string folderName = "audio-folder") => new()
         {
-            Name = name,
-            NormalizedName = name.ToUpperInvariant(),
-            ExternalId = externalId
+            OriginalName = "original.mp3",
+            FolderName = folderName,
+            TranscodeStatus = ProcessingStatus.Completed
         };
 
-    public static PlayListPictures PlayListPictures() => new()
-    {
-        OriginalName = "original.webp",
-        SmallName = "small.webp",
-        MediumName = "medium.webp",
-        LargeName = "large.webp"
-    };
-
-    public static PlayList PlayList(
-        long userId,
-        string name = "Test Playlist",
-        string? description = null,
-        PlayListPictures? pictures = null,
-        LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
-        new()
+        public static TrackAudio PendingAudio() => new()
         {
-            UserId = userId,
-            Name = name,
-            NormalizedName = name.ToUpperInvariant(),
-            Description = description,
-            Pictures = pictures ?? PlayListPictures(),
-            LifeCycleStatus = lifeCycleStatus
+            OriginalName = "original.mp3",
+            TranscodeStatus = ProcessingStatus.Pending
         };
 
-    public static AlbumPictures AlbumPictures() => new()
-    {
-        OriginalName = "original.webp",
-        SmallName = "small.webp",
-        MediumName = "medium.webp",
-        LargeName = "large.webp"
-    };
+        public static LocalTrack LocalTrack(
+            User owner,
+            string title = "Test Track",
+            double durationSeconds = 180,
+            TrackPictures? pictures = null,
+            TrackAudio? audio = null,
+            LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
+            new()
+            {
+                Title = title,
+                NormalizedTitle = title.ToUpperInvariant(),
+                DurationSeconds = durationSeconds,
+                LifeCycleStatus = lifeCycleStatus,
+                OwnerUserId = owner.Id,
+                Owner = owner,
+                Pictures = pictures ?? ProcessedPictures(),
+                Audio = audio ?? ProcessedAudio()
+            };
 
-    public static UserAlbum UserAlbum(
-        long ownerUserId,
-        string title = "Test Album",
-        string? description = null,
-        int? releaseYear = 2024,
-        AlbumPictures? pictures = null) =>
-        new()
+        public static ExternalTrack ExternalTrack(
+            string externalId = "video-id",
+            string title = "Test External Track",
+            double durationSeconds = 180,
+            TrackSource source = TrackSource.YouTube,
+            TrackPictures? pictures = null,
+            TrackAudio? audio = null,
+            LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
+            new()
+            {
+                Title = title,
+                NormalizedTitle = title.ToUpperInvariant(),
+                DurationSeconds = durationSeconds,
+                LifeCycleStatus = lifeCycleStatus,
+                Source = source,
+                ExternalId = externalId,
+                Pictures = pictures ?? ProcessedPictures(),
+                Audio = audio ?? ProcessedAudio()
+            };
+
+        public static Artist Artist(
+            string name = "Test Artist",
+            string externalId = "artist-id") =>
+            new()
+            {
+                Name = name,
+                NormalizedName = name.ToUpperInvariant(),
+                ExternalId = externalId
+            };
+
+        public static PlayListPictures PlayListPictures() => new()
         {
-            Title = title,
-            NormalizedTitle = title.ToUpperInvariant(),
-            Description = description,
-            ReleaseYear = releaseYear,
-            OwnerUserId = ownerUserId,
-            Pictures = pictures ?? AlbumPictures()
+            OriginalName = "original.webp",
+            SmallName = "small.webp",
+            MediumName = "medium.webp",
+            LargeName = "large.webp"
         };
 
-    public static ExternalAlbum ExternalAlbum(
-        string externalId = "album-id",
-        string title = "Test External Album",
-        TrackSource source = TrackSource.YouTube,
-        string? thumbnailUrl = null) =>
-        new()
+        public static PlayList PlayList(
+            long userId,
+            string name = "Test Playlist",
+            string? description = null,
+            PlayListPictures? pictures = null,
+            LifeCycleStatus lifeCycleStatus = LifeCycleStatus.Active) =>
+            new()
+            {
+                UserId = userId,
+                Name = name,
+                NormalizedName = name.ToUpperInvariant(),
+                Description = description,
+                Pictures = pictures ?? PlayListPictures(),
+                LifeCycleStatus = lifeCycleStatus
+            };
+
+        public static AlbumPictures AlbumPictures() => new()
         {
-            Title = title,
-            NormalizedTitle = title.ToUpperInvariant(),
-            Source = source,
-            ExternalId = externalId,
-            ThumbnailUrl = thumbnailUrl
+            OriginalName = "original.webp",
+            SmallName = "small.webp",
+            MediumName = "medium.webp",
+            LargeName = "large.webp"
         };
 
-    public static UploadIntent UploadIntent(
-        long userId,
-        UploadIntentPurpose purpose = UploadIntentPurpose.TrackPicture,
-        string bucket = "test-bucket",
-        string key = "temp/object.webp",
-        string objectName = "object.webp",
-        string contentType = "image/webp",
-        long? expectedSizeBytes = 1024,
-        UploadIntentStatus status = UploadIntentStatus.Issued,
-        DateTime? expiresAt = null) =>
-        new()
-        {
-            UserId = userId,
-            Bucket = bucket,
-            Key = key,
-            ObjectName = objectName,
-            ContentType = contentType,
-            ExpectedSizeBytes = expectedSizeBytes,
-            Purpose = purpose,
-            Status = status,
-            ExpiresAt = expiresAt ?? DateTime.UtcNow.AddMinutes(5)
-        };
+        public static UserAlbum UserAlbum(
+            long ownerUserId,
+            string title = "Test Album",
+            string? description = null,
+            int? releaseYear = 2024,
+            AlbumPictures? pictures = null) =>
+            new()
+            {
+                Title = title,
+                NormalizedTitle = title.ToUpperInvariant(),
+                Description = description,
+                ReleaseYear = releaseYear,
+                OwnerUserId = ownerUserId,
+                Pictures = pictures ?? AlbumPictures()
+            };
 
-    public static Mix Mix(
-        long userId,
-        string title = "Test Mix",
-        string? subtitle = null,
-        int position = 0) =>
-        new()
-        {
-            UserId = userId,
-            Title = title,
-            Subtitle = subtitle,
-            Position = position
-        };
+        public static ExternalAlbum ExternalAlbum(
+            string externalId = "album-id",
+            string title = "Test External Album",
+            TrackSource source = TrackSource.YouTube,
+            string? thumbnailUrl = null) =>
+            new()
+            {
+                Title = title,
+                NormalizedTitle = title.ToUpperInvariant(),
+                Source = source,
+                ExternalId = externalId,
+                ThumbnailUrl = thumbnailUrl
+            };
 
-    public static MixItem MixItem(
-        Guid mixId,
-        int position = 0,
-        MixItemSource source = MixItemSource.Musify,
-        Guid? trackId = null,
-        string? videoId = null,
-        string title = "Test Mix Item",
-        string? artist = "Test Artist",
-        double durationSeconds = 180,
-        bool isExplicit = false) =>
-        new()
-        {
-            MixId = mixId,
-            Position = position,
-            Source = source,
-            TrackId = trackId,
-            VideoId = videoId,
-            Title = title,
-            Artist = artist,
-            DurationSeconds = durationSeconds,
-            IsExplicit = isExplicit
-        };
+        public static UploadIntent UploadIntent(
+            long userId,
+            UploadIntentPurpose purpose = UploadIntentPurpose.TrackPicture,
+            string bucket = "test-bucket",
+            string key = "temp/object.webp",
+            string objectName = "object.webp",
+            string contentType = "image/webp",
+            long? expectedSizeBytes = 1024,
+            UploadIntentStatus status = UploadIntentStatus.Issued,
+            DateTime? expiresAt = null) =>
+            new()
+            {
+                UserId = userId,
+                Bucket = bucket,
+                Key = key,
+                ObjectName = objectName,
+                ContentType = contentType,
+                ExpectedSizeBytes = expectedSizeBytes,
+                Purpose = purpose,
+                Status = status,
+                ExpiresAt = expiresAt ?? DateTime.UtcNow.AddMinutes(5)
+            };
 
-    public static ListeningHistory ListeningHistory(
-        long userId,
-        Guid trackId,
-        DateTime? listenedAt = null) =>
-        new()
-        {
-            UserId = userId,
-            TrackId = trackId,
-            ListenedAt = listenedAt ?? DateTime.UtcNow
-        };
+        public static Mix Mix(
+            long userId,
+            string title = "Test Mix",
+            string? subtitle = null,
+            int position = 0) =>
+            new()
+            {
+                UserId = userId,
+                Title = title,
+                Subtitle = subtitle,
+                Position = position
+            };
+
+        public static MixItem MixItem(
+            Guid mixId,
+            int position = 0,
+            MixItemSource source = MixItemSource.Musify,
+            Guid? trackId = null,
+            string? videoId = null,
+            string title = "Test Mix Item",
+            string? artist = "Test Artist",
+            double durationSeconds = 180,
+            bool isExplicit = false) =>
+            new()
+            {
+                MixId = mixId,
+                Position = position,
+                Source = source,
+                TrackId = trackId,
+                VideoId = videoId,
+                Title = title,
+                Artist = artist,
+                DurationSeconds = durationSeconds,
+                IsExplicit = isExplicit
+            };
+
+        public static ListeningHistory ListeningHistory(
+            long userId,
+            Guid trackId,
+            DateTime? listenedAt = null) =>
+            new()
+            {
+                UserId = userId,
+                TrackId = trackId,
+                ListenedAt = listenedAt ?? DateTime.UtcNow
+            };
+    }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/CreateTrackCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/CreateTrackCommandHandlerTests.cs
index c4a48cb..90cc775 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/CreateTrackCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/CreateTrackCommandHandlerTests.cs
@@ -7,92 +7,93 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class CreateTrackCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
-    private CreateTrackCommandHandler CreateHandler()
+    public sealed class CreateTrackCommandHandlerTests : HandlerTestBase
     {
-        storageService
-            .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-            .Returns(new ObjectMetaData("image/webp", 1024));
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
 
-        return new CreateTrackCommandHandler(
-            Database,
-            eventBus,
-            new UploadIntentValidator(Database, storageService),
-            NoOpLogger<CreateTrackCommandHandler>(),
-            TestConfigurations.Storage(),
-            TestConfigurations.Track(),
-            TestConfigurations.UploadIntent());
-    }
+        private CreateTrackCommandHandler CreateHandler()
+        {
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 1024));
 
-    private static (Domain.Entities.UploadIntent Picture, Domain.Entities.UploadIntent Audio) SeedIntents(long userId) =>
-        (TestEntities.UploadIntent(userId, UploadIntentPurpose.TrackPicture, objectName: "cover.webp"),
-         TestEntities.UploadIntent(userId, UploadIntentPurpose.TrackAudio, objectName: "song.mp3"));
+            return new CreateTrackCommandHandler(
+                Database,
+                eventBus,
+                new UploadIntentValidator(Database, storageService),
+                NoOpLogger<CreateTrackCommandHandler>(),
+                TestConfigurations.Storage(),
+                TestConfigurations.Track(),
+                TestConfigurations.UploadIntent());
+        }
 
-    [Fact]
-    public async Task Handle_ValidIntents_CreatesTrackAndPublishesEvent()
-    {
-        var user = TestEntities.User();
-        var (picture, audio) = SeedIntents(user.Id);
-        await SeedAsync(user, picture, audio);
+        private static (Domain.Entities.UploadIntent Picture, Domain.Entities.UploadIntent Audio) SeedIntents(long userId) =>
+            (TestEntities.UploadIntent(userId, UploadIntentPurpose.TrackPicture, objectName: "cover.webp"),
+             TestEntities.UploadIntent(userId, UploadIntentPurpose.TrackAudio, objectName: "song.mp3"));
 
-        var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
+        [Fact]
+        public async Task Handle_ValidIntents_CreatesTrackAndPublishesEvent()
+        {
+            var user = TestEntities.User();
+            var (picture, audio) = SeedIntents(user.Id);
+            await SeedAsync(user, picture, audio);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
 
-        Assert.False(result.IsError);
-        Assert.Equal("My Song", result.Value.Title);
-        Assert.Equal(user.Id, result.Value.OwnerUserId);
-        await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.CreateTrackResourcesEvent>(), Arg.Any<CancellationToken>());
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var stored = await Database.LocalTracks.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal(ProcessingStatus.Pending, stored.Audio.TranscodeStatus);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("My Song", result.Value.Title);
+            Assert.Equal(user.Id, result.Value.OwnerUserId);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.CreateTrackResourcesEvent>(), Arg.Any<CancellationToken>());
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var command = new CreateTrackCommand(404, "Orphan Song", Guid.NewGuid(), Guid.NewGuid());
+            var stored = await Database.LocalTracks.FindAsync([result.Value.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal(ProcessingStatus.Pending, stored.Audio.TranscodeStatus);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var command = new CreateTrackCommand(404, "Orphan Song", Guid.NewGuid(), Guid.NewGuid());
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PictureIntentBelongsToAnotherUser_ReturnsError()
-    {
-        var user = TestEntities.User(1, "user");
-        var otherUser = TestEntities.User(2, "other");
-        var (picture, audio) = SeedIntents(otherUser.Id);
-        await SeedAsync(user, otherUser, picture, audio);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
+        [Fact]
+        public async Task Handle_PictureIntentBelongsToAnotherUser_ReturnsError()
+        {
+            var user = TestEntities.User(1, "user");
+            var otherUser = TestEntities.User(2, "other");
+            var (picture, audio) = SeedIntents(otherUser.Id);
+            await SeedAsync(user, otherUser, picture, audio);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
 
-        Assert.True(result.IsError);
-        await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.CreateTrackResourcesEvent>(), Arg.Any<CancellationToken>());
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AudioIntentAlreadyConsumed_ReturnsError()
-    {
-        var user = TestEntities.User();
-        var picture = TestEntities.UploadIntent(user.Id, UploadIntentPurpose.TrackPicture, objectName: "cover.webp");
-        var audio = TestEntities.UploadIntent(user.Id, UploadIntentPurpose.TrackAudio, objectName: "song.mp3", status: UploadIntentStatus.Consumed);
-        await SeedAsync(user, picture, audio);
+            Assert.True(result.IsError);
+            await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.CreateTrackResourcesEvent>(), Arg.Any<CancellationToken>());
+        }
 
-        var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
+        [Fact]
+        public async Task Handle_AudioIntentAlreadyConsumed_ReturnsError()
+        {
+            var user = TestEntities.User();
+            var picture = TestEntities.UploadIntent(user.Id, UploadIntentPurpose.TrackPicture, objectName: "cover.webp");
+            var audio = TestEntities.UploadIntent(user.Id, UploadIntentPurpose.TrackAudio, objectName: "song.mp3", status: UploadIntentStatus.Consumed);
+            await SeedAsync(user, picture, audio);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new CreateTrackCommand(user.Id, "My Song", picture.Id, audio.Id);
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/DeleteTrackCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/DeleteTrackCommandHandlerTests.cs
index 3bd62e6..df70129 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/DeleteTrackCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/DeleteTrackCommandHandlerTests.cs
@@ -6,71 +6,72 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class DeleteTrackCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-
-    private DeleteTrackCommandHandler CreateHandler() => new(Database, eventBus, NoOpLogger<DeleteTrackCommandHandler>());
-
-    [Fact]
-    public async Task Handle_Owner_MarksTrackAsRemovingAndPublishesEvent()
+    public sealed class DeleteTrackCommandHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
 
-        var result = await CreateHandler().Handle(new DeleteTrackCommand(owner.Id, track.Id), TestContext.Current.CancellationToken);
+        private DeleteTrackCommandHandler CreateHandler() => new(Database, eventBus, NoOpLogger<DeleteTrackCommandHandler>());
 
-        Assert.False(result.IsError);
-        var stored = await Database.Tracks.FindAsync([track.Id], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal(LifeCycleStatus.Removing, stored.LifeCycleStatus);
-        await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DeleteTrackEvent>(), Arg.Any<CancellationToken>());
-    }
+        [Fact]
+        public async Task Handle_Owner_MarksTrackAsRemovingAndPublishesEvent()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new DeleteTrackCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
+            var result = await CreateHandler().Handle(new DeleteTrackCommand(owner.Id, track.Id), TestContext.Current.CancellationToken);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            Assert.False(result.IsError);
+            var stored = await Database.Tracks.FindAsync([track.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal(LifeCycleStatus.Removing, stored.LifeCycleStatus);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.DeleteTrackEvent>(), Arg.Any<CancellationToken>());
+        }
 
-    [Fact]
-    public async Task Handle_NotOwner_ReturnsUnauthorized()
-    {
-        var owner = TestEntities.User(1, "owner");
-        var stranger = TestEntities.User(2, "stranger");
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, stranger, track);
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new DeleteTrackCommand(1, Guid.NewGuid()), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new DeleteTrackCommand(stranger.Id, track.Id), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsUnauthorized()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, stranger, track);
 
-    [Fact]
-    public async Task Handle_ExternalTrack_ReturnsUnauthorized()
-    {
-        var externalTrack = TestEntities.ExternalTrack();
-        await SeedAsync(externalTrack);
+            var result = await CreateHandler().Handle(new DeleteTrackCommand(stranger.Id, track.Id), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new DeleteTrackCommand(1, externalTrack.Id), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_ExternalTrack_ReturnsUnauthorized()
+        {
+            var externalTrack = TestEntities.ExternalTrack();
+            await SeedAsync(externalTrack);
 
-    [Fact]
-    public async Task Handle_AudioStillProcessing_ReturnsConflict()
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner, audio: TestEntities.PendingAudio());
-        await SeedAsync(owner, track);
+            var result = await CreateHandler().Handle(new DeleteTrackCommand(1, externalTrack.Id), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new DeleteTrackCommand(owner.Id, track.Id), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_AudioStillProcessing_ReturnsConflict()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner, audio: TestEntities.PendingAudio());
+            await SeedAsync(owner, track);
+
+            var result = await CreateHandler().Handle(new DeleteTrackCommand(owner.Id, track.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetListeningHistoryQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetListeningHistoryQueryHandlerTests.cs
index bcae1eb..97178d0 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetListeningHistoryQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetListeningHistoryQueryHandlerTests.cs
@@ -2,37 +2,38 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Tracks;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetListeningHistoryQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private GetListeningHistoryQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_MultipleListens_ReturnsDistinctTracksMostRecentFirst()
+    public sealed class GetListeningHistoryQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var older = TestEntities.LocalTrack(owner, "Older listen");
-        var newer = TestEntities.LocalTrack(owner, "Newer listen");
-        await SeedAsync(
-            owner, older, newer,
-            TestEntities.ListeningHistory(owner.Id, older.Id, DateTime.UtcNow.AddMinutes(-10)),
-            TestEntities.ListeningHistory(owner.Id, older.Id, DateTime.UtcNow.AddMinutes(-5)),
-            TestEntities.ListeningHistory(owner.Id, newer.Id, DateTime.UtcNow));
+        private GetListeningHistoryQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetListeningHistoryQuery(owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_MultipleListens_ReturnsDistinctTracksMostRecentFirst()
+        {
+            var owner = TestEntities.User();
+            var older = TestEntities.LocalTrack(owner, "Older listen");
+            var newer = TestEntities.LocalTrack(owner, "Newer listen");
+            await SeedAsync(
+                owner, older, newer,
+                TestEntities.ListeningHistory(owner.Id, older.Id, DateTime.UtcNow.AddMinutes(-10)),
+                TestEntities.ListeningHistory(owner.Id, older.Id, DateTime.UtcNow.AddMinutes(-5)),
+                TestEntities.ListeningHistory(owner.Id, newer.Id, DateTime.UtcNow));
 
-        Assert.Equal(["Newer listen", "Older listen"], result.Select(track => track.Title));
-    }
+            var result = await CreateHandler().Handle(new GetListeningHistoryQuery(owner.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NoHistory_ReturnsEmpty()
-    {
-        var owner = TestEntities.User();
-        await SeedAsync(owner);
+            Assert.Equal(["Newer listen", "Older listen"], result.Select(track => track.Title));
+        }
 
-        var result = await CreateHandler().Handle(new GetListeningHistoryQuery(owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoHistory_ReturnsEmpty()
+        {
+            var owner = TestEntities.User();
+            await SeedAsync(owner);
 
-        Assert.Empty(result);
+            var result = await CreateHandler().Handle(new GetListeningHistoryQuery(owner.Id), TestContext.Current.CancellationToken);
+
+            Assert.Empty(result);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackByIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackByIdQueryHandlerTests.cs
index 645a4f6..0e7cd05 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackByIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackByIdQueryHandlerTests.cs
@@ -3,32 +3,33 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Tracks;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetTrackByIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private GetTrackByIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_LocalTrack_ReturnsItWithOwnerAsArtist()
+    public sealed class GetTrackByIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User(1, "artist-name");
-        var track = TestEntities.LocalTrack(owner, "My Song");
-        await SeedAsync(owner, track);
+        private GetTrackByIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetTrackByIdQuery(track.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_LocalTrack_ReturnsItWithOwnerAsArtist()
+        {
+            var owner = TestEntities.User(1, "artist-name");
+            var track = TestEntities.LocalTrack(owner, "My Song");
+            await SeedAsync(owner, track);
 
-        Assert.False(result.IsError);
-        Assert.Equal("My Song", result.Value.Title);
-        Assert.Equal(owner.Name, result.Value.Artist);
-        Assert.Equal(owner.Id, result.Value.OwnerUserId);
-    }
+            var result = await CreateHandler().Handle(new GetTrackByIdQuery(track.Id), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetTrackByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("My Song", result.Value.Title);
+            Assert.Equal(owner.Name, result.Value.Artist);
+            Assert.Equal(owner.Id, result.Value.OwnerUserId);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetTrackByIdQuery(Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackCoverQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackCoverQueryHandlerTests.cs
index 0a524af..c1144a1 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackCoverQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackCoverQueryHandlerTests.cs
@@ -3,49 +3,50 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Tracks;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetTrackCoverQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private GetTrackCoverQueryHandler CreateHandler() =>
-        new(Database, TestConfigurations.Storage("covers-bucket"), TestConfigurations.Track());
-
-    [Theory]
-    [InlineData("small", "small.webp")]
-    [InlineData("medium", "medium.webp")]
-    [InlineData("large", "large.webp")]
-    [InlineData("unknown-size-falls-back-to-medium", "medium.webp")]
-    public async Task Handle_ProcessedTrack_ReturnsRequestedSize(string size, string expectedFileName)
+    public sealed class GetTrackCoverQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+        private GetTrackCoverQueryHandler CreateHandler() =>
+            new(Database, TestConfigurations.Storage("covers-bucket"), TestConfigurations.Track());
 
-        var result = await CreateHandler().Handle(new GetTrackCoverQuery(track.Id, size), TestContext.Current.CancellationToken);
+        [Theory]
+        [InlineData("small", "small.webp")]
+        [InlineData("medium", "medium.webp")]
+        [InlineData("large", "large.webp")]
+        [InlineData("unknown-size-falls-back-to-medium", "medium.webp")]
+        public async Task Handle_ProcessedTrack_ReturnsRequestedSize(string size, string expectedFileName)
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
 
-        Assert.False(result.IsError);
-        Assert.Equal("covers-bucket", result.Value.Bucket);
-        Assert.EndsWith(expectedFileName, result.Value.Key);
-        Assert.Equal("image/webp", result.Value.ContentType);
-    }
+            var result = await CreateHandler().Handle(new GetTrackCoverQuery(track.Id, size), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetTrackCoverQuery(Guid.NewGuid(), "small"), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("covers-bucket", result.Value.Bucket);
+            Assert.EndsWith(expectedFileName, result.Value.Key);
+            Assert.Equal("image/webp", result.Value.ContentType);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetTrackCoverQuery(Guid.NewGuid(), "small"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_PictureNotProcessedYet_ReturnsNotFound()
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner, pictures: TestEntities.PendingPictures());
-        await SeedAsync(owner, track);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new GetTrackCoverQuery(track.Id, "small"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_PictureNotProcessedYet_ReturnsNotFound()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner, pictures: TestEntities.PendingPictures());
+            await SeedAsync(owner, track);
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new GetTrackCoverQuery(track.Id, "small"), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackStreamQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackStreamQueryHandlerTests.cs
index 78a0006..ccfdc4b 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetTrackStreamQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetTrackStreamQueryHandlerTests.cs
@@ -7,61 +7,62 @@ using Musify.Application.Tracks;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetTrackStreamQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
-
-    private GetTrackStreamQueryHandler CreateHandler()
+    public sealed class GetTrackStreamQueryHandlerTests : HandlerTestBase
     {
-        ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("ticket-token", 60));
+        private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
 
-        var issuer = new TrackStreamIssuer(
-            Database,
-            ticketService,
-            TestConfigurations.Track(),
-            TestConfigurations.StreamGateway("https://stream.musify.test"));
+        private GetTrackStreamQueryHandler CreateHandler()
+        {
+            ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("ticket-token", 60));
 
-        return new GetTrackStreamQueryHandler(Database, issuer, NoOpLogger<GetTrackStreamQueryHandler>());
-    }
+            var issuer = new TrackStreamIssuer(
+                Database,
+                ticketService,
+                TestConfigurations.Track(),
+                TestConfigurations.StreamGateway("https://stream.musify.test"));
 
-    [Fact]
-    public async Task Handle_ProcessedTrack_IssuesTicketAndRecordsListen()
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track);
+            return new GetTrackStreamQueryHandler(Database, issuer, NoOpLogger<GetTrackStreamQueryHandler>());
+        }
 
-        var result = await CreateHandler().Handle(new GetTrackStreamQuery(track.Id, owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ProcessedTrack_IssuesTicketAndRecordsListen()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track);
 
-        Assert.False(result.IsError);
-        Assert.Equal("ticket-token", result.Value.Ticket);
-        Assert.Equal(60, result.Value.ExpiresInSeconds);
-        Assert.Contains("audio-folder", result.Value.ManifestUrl);
+            var result = await CreateHandler().Handle(new GetTrackStreamQuery(track.Id, owner.Id), TestContext.Current.CancellationToken);
 
-        var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(owner.Id, history.UserId);
-        Assert.Equal(track.Id, history.TrackId);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("ticket-token", result.Value.Ticket);
+            Assert.Equal(60, result.Value.ExpiresInSeconds);
+            Assert.Contains("audio-folder", result.Value.ManifestUrl);
 
-    [Fact]
-    public async Task Handle_TrackMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetTrackStreamQuery(Guid.NewGuid(), 1), TestContext.Current.CancellationToken);
+            var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(owner.Id, history.UserId);
+            Assert.Equal(track.Id, history.TrackId);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_TrackMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetTrackStreamQuery(Guid.NewGuid(), 1), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_AudioNotProcessedYet_ReturnsConflict()
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner, audio: TestEntities.PendingAudio());
-        await SeedAsync(owner, track);
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new GetTrackStreamQuery(track.Id, owner.Id), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_AudioNotProcessedYet_ReturnsConflict()
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner, audio: TestEntities.PendingAudio());
+            await SeedAsync(owner, track);
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+            var result = await CreateHandler().Handle(new GetTrackStreamQuery(track.Id, owner.Id), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetTracksByUserIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetTracksByUserIdQueryHandlerTests.cs
index 5a76cf8..1a24965 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetTracksByUserIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetTracksByUserIdQueryHandlerTests.cs
@@ -3,43 +3,44 @@ using Musify.Application.Tracks;
 using Musify.Domain.Entities;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetTracksByUserIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private GetTracksByUserIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ReturnsOnlyTracksLinkedToThatUser()
+    public sealed class GetTracksByUserIdQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User(1, "owner");
-        var other = TestEntities.User(2, "other");
-        var mine = TestEntities.LocalTrack(owner, "Mine");
-        var theirs = TestEntities.LocalTrack(other, "Theirs");
-        await SeedAsync(
-            owner, other, mine, theirs,
-            new UserHasTrack { UserId = owner.Id, TrackId = mine.Id },
-            new UserHasTrack { UserId = other.Id, TrackId = theirs.Id });
+        private GetTracksByUserIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetTracksByUserIdQuery(owner.Id, Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ReturnsOnlyTracksLinkedToThatUser()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var other = TestEntities.User(2, "other");
+            var mine = TestEntities.LocalTrack(owner, "Mine");
+            var theirs = TestEntities.LocalTrack(other, "Theirs");
+            await SeedAsync(
+                owner, other, mine, theirs,
+                new UserHasTrack { UserId = owner.Id, TrackId = mine.Id },
+                new UserHasTrack { UserId = other.Id, TrackId = theirs.Id });
 
-        Assert.False(result.IsError);
-        var track = Assert.Single(result.Value.Items);
-        Assert.Equal("Mine", track.Title);
-    }
+            var result = await CreateHandler().Handle(new GetTracksByUserIdQuery(owner.Id, Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Theory]
-    [InlineData(0, 1)]
-    [InlineData(-5, 1)]
-    public async Task Handle_NonPositivePageNumber_FallsBackToFirstPage(int requestedPageNumber, int expectedPageNumber)
-    {
-        var owner = TestEntities.User();
-        var track = TestEntities.LocalTrack(owner);
-        await SeedAsync(owner, track, new UserHasTrack { UserId = owner.Id, TrackId = track.Id });
+            Assert.False(result.IsError);
+            var track = Assert.Single(result.Value.Items);
+            Assert.Equal("Mine", track.Title);
+        }
 
-        var result = await CreateHandler().Handle(new GetTracksByUserIdQuery(owner.Id, Name: null, PageNumber: requestedPageNumber, PageSize: 10), TestContext.Current.CancellationToken);
+        [Theory]
+        [InlineData(0, 1)]
+        [InlineData(-5, 1)]
+        public async Task Handle_NonPositivePageNumber_FallsBackToFirstPage(int requestedPageNumber, int expectedPageNumber)
+        {
+            var owner = TestEntities.User();
+            var track = TestEntities.LocalTrack(owner);
+            await SeedAsync(owner, track, new UserHasTrack { UserId = owner.Id, TrackId = track.Id });
 
-        Assert.False(result.IsError);
-        Assert.Equal(expectedPageNumber, result.Value.PageNumber);
+            var result = await CreateHandler().Handle(new GetTracksByUserIdQuery(owner.Id, Name: null, PageNumber: requestedPageNumber, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal(expectedPageNumber, result.Value.PageNumber);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/GetTracksQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/GetTracksQueryHandlerTests.cs
index dd1854a..4867871 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/GetTracksQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/GetTracksQueryHandlerTests.cs
@@ -2,44 +2,45 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Tracks;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class GetTracksQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private GetTracksQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_NoNameFilter_ReturnsEveryTrackAUserOwns()
+    public sealed class GetTracksQueryHandlerTests : HandlerTestBase
     {
-        var owner = TestEntities.User();
-        var trackA = TestEntities.LocalTrack(owner, "Alpha");
-        var trackB = TestEntities.LocalTrack(owner, "Beta");
-        await SeedAsync(
-            owner, trackA, trackB,
-            new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = trackA.Id },
-            new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = trackB.Id });
+        private GetTracksQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetTracksQuery(Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoNameFilter_ReturnsEveryTrackAUserOwns()
+        {
+            var owner = TestEntities.User();
+            var trackA = TestEntities.LocalTrack(owner, "Alpha");
+            var trackB = TestEntities.LocalTrack(owner, "Beta");
+            await SeedAsync(
+                owner, trackA, trackB,
+                new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = trackA.Id },
+                new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = trackB.Id });
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.TotalItemCount);
-    }
+            var result = await CreateHandler().Handle(new GetTracksQuery(Name: null, PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_NameFilter_ReturnsOnlyMatchingTracks()
-    {
-        var owner = TestEntities.User();
-        var match = TestEntities.LocalTrack(owner, "Bohemian Rhapsody");
-        var other = TestEntities.LocalTrack(owner, "Imagine");
-        await SeedAsync(
-            owner, match, other,
-            new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = match.Id },
-            new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = other.Id });
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.TotalItemCount);
+        }
 
-        var result = await CreateHandler().Handle(new GetTracksQuery(Name: "rhapsody", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NameFilter_ReturnsOnlyMatchingTracks()
+        {
+            var owner = TestEntities.User();
+            var match = TestEntities.LocalTrack(owner, "Bohemian Rhapsody");
+            var other = TestEntities.LocalTrack(owner, "Imagine");
+            await SeedAsync(
+                owner, match, other,
+                new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = match.Id },
+                new Musify.Domain.Entities.UserHasTrack { UserId = owner.Id, TrackId = other.Id });
 
-        Assert.False(result.IsError);
-        var track = Assert.Single(result.Value.Items);
-        Assert.Equal("Bohemian Rhapsody", track.Title);
+            var result = await CreateHandler().Handle(new GetTracksQuery(Name: "rhapsody", PageNumber: 1, PageSize: 10), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var track = Assert.Single(result.Value.Items);
+            Assert.Equal("Bohemian Rhapsody", track.Title);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Tracks/RequestTrackUploadUrlsCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Tracks/RequestTrackUploadUrlsCommandHandlerTests.cs
index eab3b41..8867b86 100644
--- a/backend/Tests/Musify.Application.Tests/Tracks/RequestTrackUploadUrlsCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Tracks/RequestTrackUploadUrlsCommandHandlerTests.cs
@@ -9,72 +9,73 @@ using Musify.Domain.ValueObjects;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.Tracks;
-
-public sealed class RequestTrackUploadUrlsCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Tracks
 {
-    private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
-    private RequestTrackUploadUrlsCommandHandler CreateHandler(UploadIntentConfiguration? uploadIntentConfig = null)
+    public sealed class RequestTrackUploadUrlsCommandHandlerTests : HandlerTestBase
     {
-        storageService
-            .GetUploadUrlAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<TimeSpan>(), Arg.Any<CancellationToken>())
-            .Returns("https://storage.musify.test/presigned-upload");
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
 
-        return new RequestTrackUploadUrlsCommandHandler(
-            Database,
-            new UploadIntentValidator(Database, storageService),
-            storageService,
-            NoOpLogger<RequestTrackUploadUrlsCommandHandler>(),
-            TestConfigurations.Storage(),
-            TestConfigurations.Track(),
-            uploadIntentConfig ?? TestConfigurations.UploadIntent());
-    }
+        private RequestTrackUploadUrlsCommandHandler CreateHandler(UploadIntentConfiguration? uploadIntentConfig = null)
+        {
+            storageService
+                .GetUploadUrlAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<TimeSpan>(), Arg.Any<CancellationToken>())
+                .Returns("https://storage.musify.test/presigned-upload");
 
-    [Fact]
-    public async Task Handle_UserExists_IssuesBothUploadUrlsAndCreatesIntents()
-    {
-        var user = TestEntities.User();
-        await SeedAsync(user);
+            return new RequestTrackUploadUrlsCommandHandler(
+                Database,
+                new UploadIntentValidator(Database, storageService),
+                storageService,
+                NoOpLogger<RequestTrackUploadUrlsCommandHandler>(),
+                TestConfigurations.Storage(),
+                TestConfigurations.Track(),
+                uploadIntentConfig ?? TestConfigurations.UploadIntent());
+        }
 
-        var command = new RequestTrackUploadUrlsCommand(user.Id, "webp", "image/webp", "mp3", "audio/mpeg");
+        [Fact]
+        public async Task Handle_UserExists_IssuesBothUploadUrlsAndCreatesIntents()
+        {
+            var user = TestEntities.User();
+            await SeedAsync(user);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new RequestTrackUploadUrlsCommand(user.Id, "webp", "image/webp", "mp3", "audio/mpeg");
 
-        Assert.False(result.IsError);
-        Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.PictureUploadUrl);
-        Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.AudioUploadUrl);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var intents = await Database.UploadIntents.Where(intent => intent.UserId == user.Id).ToListAsync(TestContext.Current.CancellationToken);
-        Assert.Equal(2, intents.Count);
-        Assert.Contains(intents, intent => intent.Purpose == UploadIntentPurpose.TrackPicture);
-        Assert.Contains(intents, intent => intent.Purpose == UploadIntentPurpose.TrackAudio);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.PictureUploadUrl);
+            Assert.Equal("https://storage.musify.test/presigned-upload", result.Value.AudioUploadUrl);
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var command = new RequestTrackUploadUrlsCommand(404, "webp", "image/webp", "mp3", "audio/mpeg");
+            var intents = await Database.UploadIntents.Where(intent => intent.UserId == user.Id).ToListAsync(TestContext.Current.CancellationToken);
+            Assert.Equal(2, intents.Count);
+            Assert.Contains(intents, intent => intent.Purpose == UploadIntentPurpose.TrackPicture);
+            Assert.Contains(intents, intent => intent.Purpose == UploadIntentPurpose.TrackAudio);
+        }
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var command = new RequestTrackUploadUrlsCommand(404, "webp", "image/webp", "mp3", "audio/mpeg");
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UserAtActiveIntentLimit_ReturnsValidationErrorAndCreatesNothing()
-    {
-        var config = TestConfigurations.UploadIntent();
-        config.MaxActiveUploadIntentsPerUser = 1;
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
 
-        var user = TestEntities.User();
-        await SeedAsync(user, TestEntities.UploadIntent(user.Id));
+        [Fact]
+        public async Task Handle_UserAtActiveIntentLimit_ReturnsValidationErrorAndCreatesNothing()
+        {
+            var config = TestConfigurations.UploadIntent();
+            config.MaxActiveUploadIntentsPerUser = 1;
 
-        var command = new RequestTrackUploadUrlsCommand(user.Id, "webp", "image/webp", "mp3", "audio/mpeg");
+            var user = TestEntities.User();
+            await SeedAsync(user, TestEntities.UploadIntent(user.Id));
 
-        var result = await CreateHandler(config).Handle(command, TestContext.Current.CancellationToken);
+            var command = new RequestTrackUploadUrlsCommand(user.Id, "webp", "image/webp", "mp3", "audio/mpeg");
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-        Assert.Equal(1, await Database.UploadIntents.CountAsync(TestContext.Current.CancellationToken));
+            var result = await CreateHandler(config).Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+            Assert.Equal(1, await Database.UploadIntents.CountAsync(TestContext.Current.CancellationToken));
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Users/CreateUserCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Users/CreateUserCommandHandlerTests.cs
index 1dd4718..eb15fa6 100644
--- a/backend/Tests/Musify.Application.Tests/Users/CreateUserCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Users/CreateUserCommandHandlerTests.cs
@@ -3,38 +3,39 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Users;
 using Xunit;
 
-namespace Musify.Application.Tests.Users;
-
-public sealed class CreateUserCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Users
 {
-    private CreateUserCommandHandler CreateHandler() => new(Database, NoOpLogger<CreateUserCommandHandler>());
-
-    [Fact]
-    public async Task Handle_NewId_CreatesUser()
+    public sealed class CreateUserCommandHandlerTests : HandlerTestBase
     {
-        var command = new CreateUserCommand(1, "Jane Doe", "Jane", "Doe");
+        private CreateUserCommandHandler CreateHandler() => new(Database, NoOpLogger<CreateUserCommandHandler>());
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NewId_CreatesUser()
+        {
+            var command = new CreateUserCommand(1, "Jane Doe", "Jane", "Doe");
 
-        Assert.False(result.IsError);
-        Assert.Equal("Jane Doe", result.Value.Name);
-        Assert.Equal(1, result.Value.Id);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-        var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("JANE DOE", stored.NormalizedName);
-    }
+            Assert.False(result.IsError);
+            Assert.Equal("Jane Doe", result.Value.Name);
+            Assert.Equal(1, result.Value.Id);
 
-    [Fact]
-    public async Task Handle_IdAlreadyExists_ReturnsConflict()
-    {
-        var existing = TestEntities.User(1);
-        await SeedAsync(existing);
+            var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("JANE DOE", stored.NormalizedName);
+        }
 
-        var command = new CreateUserCommand(1, "Someone Else", null, null);
+        [Fact]
+        public async Task Handle_IdAlreadyExists_ReturnsConflict()
+        {
+            var existing = TestEntities.User(1);
+            await SeedAsync(existing);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new CreateUserCommand(1, "Someone Else", null, null);
 
-        Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Users/GetUserByIdQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Users/GetUserByIdQueryHandlerTests.cs
index 2bcb0ac..1854be6 100644
--- a/backend/Tests/Musify.Application.Tests/Users/GetUserByIdQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Users/GetUserByIdQueryHandlerTests.cs
@@ -3,29 +3,30 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Users;
 using Xunit;
 
-namespace Musify.Application.Tests.Users;
-
-public sealed class GetUserByIdQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Users
 {
-    private GetUserByIdQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_ExistingUser_ReturnsIt()
+    public sealed class GetUserByIdQueryHandlerTests : HandlerTestBase
     {
-        var user = TestEntities.User(1, "Jane Doe");
-        await SeedAsync(user);
+        private GetUserByIdQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetUserByIdQuery(1), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ExistingUser_ReturnsIt()
+        {
+            var user = TestEntities.User(1, "Jane Doe");
+            await SeedAsync(user);
 
-        Assert.False(result.IsError);
-        Assert.Equal("Jane Doe", result.Value.Name);
-    }
+            var result = await CreateHandler().Handle(new GetUserByIdQuery(1), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UserMissing_ReturnsNotFound()
-    {
-        var result = await CreateHandler().Handle(new GetUserByIdQuery(404), TestContext.Current.CancellationToken);
+            Assert.False(result.IsError);
+            Assert.Equal("Jane Doe", result.Value.Name);
+        }
 
-        Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        [Fact]
+        public async Task Handle_UserMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new GetUserByIdQuery(404), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Users/GetUsersQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Users/GetUsersQueryHandlerTests.cs
index 516e6b1..f60f180 100644
--- a/backend/Tests/Musify.Application.Tests/Users/GetUsersQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Users/GetUsersQueryHandlerTests.cs
@@ -2,32 +2,33 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Users;
 using Xunit;
 
-namespace Musify.Application.Tests.Users;
-
-public sealed class GetUsersQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Users
 {
-    private GetUsersQueryHandler CreateHandler() => new(Database);
-
-    [Fact]
-    public async Task Handle_NoSearch_ReturnsEveryUser()
+    public sealed class GetUsersQueryHandlerTests : HandlerTestBase
     {
-        await SeedAsync(TestEntities.User(1, "alice"), TestEntities.User(2, "bob"));
+        private GetUsersQueryHandler CreateHandler() => new(Database);
 
-        var result = await CreateHandler().Handle(new GetUsersQuery(PageNumber: 1, PageSize: 10, UsernameSearch: null), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_NoSearch_ReturnsEveryUser()
+        {
+            await SeedAsync(TestEntities.User(1, "alice"), TestEntities.User(2, "bob"));
 
-        Assert.False(result.IsError);
-        Assert.Equal(2, result.Value.TotalItemCount);
-    }
+            var result = await CreateHandler().Handle(new GetUsersQuery(PageNumber: 1, PageSize: 10, UsernameSearch: null), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UsernameSearch_ReturnsOnlyMatches()
-    {
-        await SeedAsync(TestEntities.User(1, "alice-wonderland"), TestEntities.User(2, "bob-builder"));
+            Assert.False(result.IsError);
+            Assert.Equal(2, result.Value.TotalItemCount);
+        }
 
-        var result = await CreateHandler().Handle(new GetUsersQuery(PageNumber: 1, PageSize: 10, UsernameSearch: "alice"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UsernameSearch_ReturnsOnlyMatches()
+        {
+            await SeedAsync(TestEntities.User(1, "alice-wonderland"), TestEntities.User(2, "bob-builder"));
 
-        Assert.False(result.IsError);
-        var user = Assert.Single(result.Value.Items);
-        Assert.Equal(1, user.Id);
+            var result = await CreateHandler().Handle(new GetUsersQuery(PageNumber: 1, PageSize: 10, UsernameSearch: "alice"), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var user = Assert.Single(result.Value.Items);
+            Assert.Equal(1, user.Id);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/Users/SyncUserCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/Users/SyncUserCommandHandlerTests.cs
index 4a73c0f..3702165 100644
--- a/backend/Tests/Musify.Application.Tests/Users/SyncUserCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/Users/SyncUserCommandHandlerTests.cs
@@ -2,41 +2,42 @@ using Musify.Application.Tests.TestSupport;
 using Musify.Application.Users;
 using Xunit;
 
-namespace Musify.Application.Tests.Users;
-
-public sealed class SyncUserCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.Users
 {
-    private SyncUserCommandHandler CreateHandler() => new(Database, NoOpLogger<SyncUserCommandHandler>());
-
-    [Fact]
-    public async Task Handle_UnknownUser_ProvisionsIt()
+    public sealed class SyncUserCommandHandlerTests : HandlerTestBase
     {
-        var command = new SyncUserCommand(1, "Jane Doe", "Jane", "Doe", "https://avatar.example/jane.png");
+        private SyncUserCommandHandler CreateHandler() => new(Database, NoOpLogger<SyncUserCommandHandler>());
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UnknownUser_ProvisionsIt()
+        {
+            var command = new SyncUserCommand(1, "Jane Doe", "Jane", "Doe", "https://avatar.example/jane.png");
 
-        Assert.False(result.IsError);
-        var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("Jane Doe", stored.Name);
-        Assert.Equal("https://avatar.example/jane.png", stored.ProfilePictureUrl);
-    }
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_ExistingUser_UpdatesProfileFields()
-    {
-        var user = TestEntities.User(1, "Old Name", profilePictureUrl: null);
-        await SeedAsync(user);
+            Assert.False(result.IsError);
+            var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("Jane Doe", stored.Name);
+            Assert.Equal("https://avatar.example/jane.png", stored.ProfilePictureUrl);
+        }
 
-        var command = new SyncUserCommand(1, "New Name", "New", "Name", "https://avatar.example/new.png");
+        [Fact]
+        public async Task Handle_ExistingUser_UpdatesProfileFields()
+        {
+            var user = TestEntities.User(1, "Old Name", profilePictureUrl: null);
+            await SeedAsync(user);
 
-        var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var command = new SyncUserCommand(1, "New Name", "New", "Name", "https://avatar.example/new.png");
 
-        Assert.False(result.IsError);
-        var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
-        Assert.NotNull(stored);
-        Assert.Equal("New Name", stored.Name);
-        Assert.Equal("NEW NAME", stored.NormalizedName);
-        Assert.Equal("https://avatar.example/new.png", stored.ProfilePictureUrl);
+            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            var stored = await Database.Users.FindAsync([1L], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("New Name", stored.Name);
+            Assert.Equal("NEW NAME", stored.NormalizedName);
+            Assert.Equal("https://avatar.example/new.png", stored.ProfilePictureUrl);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/YouTube/GetYouTubeAlbumQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/YouTube/GetYouTubeAlbumQueryHandlerTests.cs
index b438db4..ff13a7d 100644
--- a/backend/Tests/Musify.Application.Tests/YouTube/GetYouTubeAlbumQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/YouTube/GetYouTubeAlbumQueryHandlerTests.cs
@@ -7,55 +7,56 @@ using Musify.Application.YouTube;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.YouTube;
-
-public sealed class GetYouTubeAlbumQueryHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.YouTube
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private GetYouTubeAlbumQueryHandler CreateHandler()
+    public sealed class GetYouTubeAlbumQueryHandlerTests : HandlerTestBase
     {
-        var provisioner = new YouTubeTrackProvisioner(
-            Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        return new GetYouTubeAlbumQueryHandler(youTubeMusicService, provisioner, NoOpLogger<GetYouTubeAlbumQueryHandler>());
-    }
+        private GetYouTubeAlbumQueryHandler CreateHandler()
+        {
+            var provisioner = new YouTubeTrackProvisioner(
+                Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
 
-    private static YouTubeAlbumDetail BuildDetail() => new(
-        new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false, []),
-        Description: "An album",
-        TotalDurationSeconds: 600,
-        Tracks: [new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false)]);
+            return new GetYouTubeAlbumQueryHandler(youTubeMusicService, provisioner, NoOpLogger<GetYouTubeAlbumQueryHandler>());
+        }
 
-    [Fact]
-    public async Task Handle_EmptyAlbumId_ReturnsValidationError()
-    {
-        var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery(string.Empty), TestContext.Current.CancellationToken);
+        private static YouTubeAlbumDetail BuildDetail() => new(
+            new YouTubeAlbumResult("album-1", "Album Title", "Album Artist", "https://img/thumb.jpg", 2024, false, false, []),
+            Description: "An album",
+            TotalDurationSeconds: 600,
+            Tracks: [new YouTubeAlbumTrack("track-1", "Track One", 200, 1, false)]);
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task Handle_EmptyAlbumId_ReturnsValidationError()
+        {
+            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery(string.Empty), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_ServiceSucceeds_MaterializesAlbumAndReturnsDetail()
-    {
-        var detail = BuildDetail();
-        youTubeMusicService.GetAlbumAsync("album-1", Arg.Any<CancellationToken>()).Returns(detail);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+        }
 
-        var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("album-1"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ServiceSucceeds_MaterializesAlbumAndReturnsDetail()
+        {
+            var detail = BuildDetail();
+            youTubeMusicService.GetAlbumAsync("album-1", Arg.Any<CancellationToken>()).Returns(detail);
 
-        Assert.False(result.IsError);
-        Assert.Same(detail, result.Value);
-        Assert.NotEmpty(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
-    }
+            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("album-1"), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_ServiceFails_ReturnsError()
-    {
-        youTubeMusicService.GetAlbumAsync("missing", Arg.Any<CancellationToken>())
-            .Returns(Error.NotFound(description: "Album not found"));
+            Assert.False(result.IsError);
+            Assert.Same(detail, result.Value);
+            Assert.NotEmpty(await Database.ExternalAlbums.ToListAsync(TestContext.Current.CancellationToken));
+        }
 
-        var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("missing"), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_ServiceFails_ReturnsError()
+        {
+            youTubeMusicService.GetAlbumAsync("missing", Arg.Any<CancellationToken>())
+                .Returns(Error.NotFound(description: "Album not found"));
 
-        Assert.True(result.IsError);
+            var result = await CreateHandler().Handle(new GetYouTubeAlbumQuery("missing"), TestContext.Current.CancellationToken);
+
+            Assert.True(result.IsError);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/YouTube/ResolveYouTubeTrackStreamCommandHandlerTests.cs b/backend/Tests/Musify.Application.Tests/YouTube/ResolveYouTubeTrackStreamCommandHandlerTests.cs
index 3ffbb46..300f64b 100644
--- a/backend/Tests/Musify.Application.Tests/YouTube/ResolveYouTubeTrackStreamCommandHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/YouTube/ResolveYouTubeTrackStreamCommandHandlerTests.cs
@@ -7,59 +7,60 @@ using Musify.Application.YouTube.Responses;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.YouTube;
-
-public sealed class ResolveYouTubeTrackStreamCommandHandlerTests : HandlerTestBase
+namespace Musify.Application.Tests.YouTube
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-    private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
-
-    private ResolveYouTubeTrackStreamCommandHandler CreateHandler()
+    public sealed class ResolveYouTubeTrackStreamCommandHandlerTests : HandlerTestBase
     {
-        var provisioner = new YouTubeTrackProvisioner(
-            Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
-        var issuer = new TrackStreamIssuer(
-            Database, ticketService, TestConfigurations.Track(), TestConfigurations.StreamGateway());
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
+        private readonly IStreamTicketService ticketService = Substitute.For<IStreamTicketService>();
 
-        return new ResolveYouTubeTrackStreamCommandHandler(
-            Database, youTubeMusicService, provisioner, issuer, NoOpLogger<ResolveYouTubeTrackStreamCommandHandler>());
-    }
+        private ResolveYouTubeTrackStreamCommandHandler CreateHandler()
+        {
+            var provisioner = new YouTubeTrackProvisioner(
+                Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
+            var issuer = new TrackStreamIssuer(
+                Database, ticketService, TestConfigurations.Track(), TestConfigurations.StreamGateway());
 
-    [Fact]
-    public async Task Handle_AlreadyProcessedTrack_IssuesServerStreamWithoutCallingYouTubeForAudio()
-    {
-        ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("token", 60));
+            return new ResolveYouTubeTrackStreamCommandHandler(
+                Database, youTubeMusicService, provisioner, issuer, NoOpLogger<ResolveYouTubeTrackStreamCommandHandler>());
+        }
 
-        var user = TestEntities.User(1);
-        var track = TestEntities.ExternalTrack(externalId: "abc123");
-        await SeedAsync(user, track);
+        [Fact]
+        public async Task Handle_AlreadyProcessedTrack_IssuesServerStreamWithoutCallingYouTubeForAudio()
+        {
+            ticketService.IssueTicket(Arg.Any<long>(), Arg.Any<string>()).Returns(new StreamTicket("token", 60));
 
-        var result = await CreateHandler().Handle(new ResolveYouTubeTrackStreamCommand("abc123", 1), TestContext.Current.CancellationToken);
+            var user = TestEntities.User(1);
+            var track = TestEntities.ExternalTrack(externalId: "abc123");
+            await SeedAsync(user, track);
 
-        Assert.False(result.IsError);
-        Assert.Equal(YouTubeStreamMode.Server, result.Value.Mode);
-        Assert.Equal("token", result.Value.Ticket);
-        await youTubeMusicService.DidNotReceiveWithAnyArgs().GetAudioStreamAsync(default!, TestContext.Current.CancellationToken);
-    }
+            var result = await CreateHandler().Handle(new ResolveYouTubeTrackStreamCommand("abc123", 1), TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task Handle_UnknownTrack_ProvisionsItAndRecordsListeningHistory()
-    {
-        youTubeMusicService.GetAudioStreamAsync("new-video", Arg.Any<CancellationToken>())
-            .Returns(new YouTubeStreamInfo("https://youtube.example/stream", 300));
-        youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>())
-            .Returns(new YouTubeSongResult("new-video", "Title", "Artist", "Album", 200, "https://img/thumb.jpg", false, []));
-        youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
-        await SeedAsync(TestEntities.User(42));
+            Assert.False(result.IsError);
+            Assert.Equal(YouTubeStreamMode.Server, result.Value.Mode);
+            Assert.Equal("token", result.Value.Ticket);
+            await youTubeMusicService.DidNotReceiveWithAnyArgs().GetAudioStreamAsync(default!, TestContext.Current.CancellationToken);
+        }
 
-        var result = await CreateHandler().Handle(new ResolveYouTubeTrackStreamCommand("new-video", 42), TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task Handle_UnknownTrack_ProvisionsItAndRecordsListeningHistory()
+        {
+            youTubeMusicService.GetAudioStreamAsync("new-video", Arg.Any<CancellationToken>())
+                .Returns(new YouTubeStreamInfo("https://youtube.example/stream", 300));
+            youTubeMusicService.GetSongAsync("new-video", Arg.Any<CancellationToken>())
+                .Returns(new YouTubeSongResult("new-video", "Title", "Artist", "Album", 200, "https://img/thumb.jpg", false, []));
+            youTubeMusicService.ResolveArtworkUrl(Arg.Any<string>()).Returns(callInfo => callInfo.Arg<string>());
+            await SeedAsync(TestEntities.User(42));
 
-        Assert.False(result.IsError);
-        Assert.Equal(YouTubeStreamMode.YouTube, result.Value.Mode);
-        Assert.Equal("https://youtube.example/stream", result.Value.StreamUrl);
-        Assert.NotNull(result.Value.TrackId);
+            var result = await CreateHandler().Handle(new ResolveYouTubeTrackStreamCommand("new-video", 42), TestContext.Current.CancellationToken);
 
-        var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
-        Assert.Equal(42, history.UserId);
+            Assert.False(result.IsError);
+            Assert.Equal(YouTubeStreamMode.YouTube, result.Value.Mode);
+            Assert.Equal("https://youtube.example/stream", result.Value.StreamUrl);
+            Assert.NotNull(result.Value.TrackId);
+
+            var history = Assert.Single(await Database.ListeningHistories.ToListAsync(TestContext.Current.CancellationToken));
+            Assert.Equal(42, history.UserId);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeAlbumsQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeAlbumsQueryHandlerTests.cs
index 86290b3..9532847 100644
--- a/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeAlbumsQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeAlbumsQueryHandlerTests.cs
@@ -4,33 +4,34 @@ using Musify.Application.YouTube;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.YouTube;
-
-public sealed class SearchYouTubeAlbumsQueryHandlerTests
+namespace Musify.Application.Tests.YouTube
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private SearchYouTubeAlbumsQueryHandler CreateHandler() => new(youTubeMusicService);
-
-    [Fact]
-    public async Task Handle_EmptyQuery_ReturnsValidationErrorWithoutCallingTheService()
+    public sealed class SearchYouTubeAlbumsQueryHandlerTests
     {
-        var result = await CreateHandler().Handle(new SearchYouTubeAlbumsQuery(string.Empty, string.Empty), TestContext.Current.CancellationToken);
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-        await youTubeMusicService.DidNotReceiveWithAnyArgs()
-            .SearchAlbumsAsync(default!, default!, TestContext.Current.CancellationToken);
-    }
+        private SearchYouTubeAlbumsQueryHandler CreateHandler() => new(youTubeMusicService);
 
-    [Fact]
-    public async Task Handle_NonEmptyQuery_DelegatesToTheService()
-    {
-        var expected = new YouTubeAlbumSearchResult([], "next-token");
-        youTubeMusicService.SearchAlbumsAsync("query", "token", Arg.Any<CancellationToken>()).Returns(expected);
+        [Fact]
+        public async Task Handle_EmptyQuery_ReturnsValidationErrorWithoutCallingTheService()
+        {
+            var result = await CreateHandler().Handle(new SearchYouTubeAlbumsQuery(string.Empty, string.Empty), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new SearchYouTubeAlbumsQuery("query", "token"), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+            await youTubeMusicService.DidNotReceiveWithAnyArgs()
+                .SearchAlbumsAsync(default!, default!, TestContext.Current.CancellationToken);
+        }
 
-        Assert.False(result.IsError);
-        Assert.Same(expected, result.Value);
+        [Fact]
+        public async Task Handle_NonEmptyQuery_DelegatesToTheService()
+        {
+            var expected = new YouTubeAlbumSearchResult([], "next-token");
+            youTubeMusicService.SearchAlbumsAsync("query", "token", Arg.Any<CancellationToken>()).Returns(expected);
+
+            var result = await CreateHandler().Handle(new SearchYouTubeAlbumsQuery("query", "token"), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Same(expected, result.Value);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeTracksQueryHandlerTests.cs b/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeTracksQueryHandlerTests.cs
index d6d8aba..73c4495 100644
--- a/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeTracksQueryHandlerTests.cs
+++ b/backend/Tests/Musify.Application.Tests/YouTube/SearchYouTubeTracksQueryHandlerTests.cs
@@ -4,33 +4,34 @@ using Musify.Application.YouTube;
 using NSubstitute;
 using Xunit;
 
-namespace Musify.Application.Tests.YouTube;
-
-public sealed class SearchYouTubeTracksQueryHandlerTests
+namespace Musify.Application.Tests.YouTube
 {
-    private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-    private SearchYouTubeTracksQueryHandler CreateHandler() => new(youTubeMusicService);
-
-    [Fact]
-    public async Task Handle_EmptyQuery_ReturnsValidationErrorWithoutCallingTheService()
+    public sealed class SearchYouTubeTracksQueryHandlerTests
     {
-        var result = await CreateHandler().Handle(new SearchYouTubeTracksQuery(string.Empty, string.Empty), TestContext.Current.CancellationToken);
+        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
 
-        Assert.Equal(ErrorType.Validation, result.FirstError.Type);
-        await youTubeMusicService.DidNotReceiveWithAnyArgs()
-            .SearchSongsAsync(default!, default!, TestContext.Current.CancellationToken);
-    }
+        private SearchYouTubeTracksQueryHandler CreateHandler() => new(youTubeMusicService);
 
-    [Fact]
-    public async Task Handle_NonEmptyQuery_DelegatesToTheService()
-    {
-        var expected = new YouTubeSearchResult([], "next-token");
-        youTubeMusicService.SearchSongsAsync("query", "token", Arg.Any<CancellationToken>()).Returns(expected);
+        [Fact]
+        public async Task Handle_EmptyQuery_ReturnsValidationErrorWithoutCallingTheService()
+        {
+            var result = await CreateHandler().Handle(new SearchYouTubeTracksQuery(string.Empty, string.Empty), TestContext.Current.CancellationToken);
 
-        var result = await CreateHandler().Handle(new SearchYouTubeTracksQuery("query", "token"), TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Validation, result.FirstError.Type);
+            await youTubeMusicService.DidNotReceiveWithAnyArgs()
+                .SearchSongsAsync(default!, default!, TestContext.Current.CancellationToken);
+        }
 
-        Assert.False(result.IsError);
-        Assert.Same(expected, result.Value);
+        [Fact]
+        public async Task Handle_NonEmptyQuery_DelegatesToTheService()
+        {
+            var expected = new YouTubeSearchResult([], "next-token");
+            youTubeMusicService.SearchSongsAsync("query", "token", Arg.Any<CancellationToken>()).Returns(expected);
+
+            var result = await CreateHandler().Handle(new SearchYouTubeTracksQuery("query", "token"), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Same(expected, result.Value);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackAudioTests.cs b/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackAudioTests.cs
index 7b4e0a5..78fde26 100644
--- a/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackAudioTests.cs
+++ b/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackAudioTests.cs
@@ -1,22 +1,23 @@
 using Musify.Domain.ValueObjects;
 using Xunit;
 
-namespace Musify.Domain.Tests.ValueObjects;
-
-public sealed class TrackAudioTests
+namespace Musify.Domain.Tests.ValueObjects
 {
-    [Theory]
-    [InlineData(ProcessingStatus.Pending, false, false, true)]
-    [InlineData(ProcessingStatus.Processing, false, false, true)]
-    [InlineData(ProcessingStatus.Completed, true, false, false)]
-    [InlineData(ProcessingStatus.Failed, false, true, false)]
-    public void ComputedFlags_ReflectTranscodeStatus(
-        ProcessingStatus status, bool expectedProcessed, bool expectedFailed, bool expectedInProgress)
+    public sealed class TrackAudioTests
     {
-        var audio = new TrackAudio { TranscodeStatus = status };
+        [Theory]
+        [InlineData(ProcessingStatus.Pending, false, false, true)]
+        [InlineData(ProcessingStatus.Processing, false, false, true)]
+        [InlineData(ProcessingStatus.Completed, true, false, false)]
+        [InlineData(ProcessingStatus.Failed, false, true, false)]
+        public void ComputedFlags_ReflectTranscodeStatus(
+            ProcessingStatus status, bool expectedProcessed, bool expectedFailed, bool expectedInProgress)
+        {
+            var audio = new TrackAudio { TranscodeStatus = status };
 
-        Assert.Equal(expectedProcessed, audio.IsProcessed);
-        Assert.Equal(expectedFailed, audio.IsFailed);
-        Assert.Equal(expectedInProgress, audio.IsInProgress);
+            Assert.Equal(expectedProcessed, audio.IsProcessed);
+            Assert.Equal(expectedFailed, audio.IsFailed);
+            Assert.Equal(expectedInProgress, audio.IsInProgress);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackPicturesTests.cs b/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackPicturesTests.cs
index a9b0ca3..9ac53db 100644
--- a/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackPicturesTests.cs
+++ b/backend/Tests/Musify.Domain.Tests/ValueObjects/TrackPicturesTests.cs
@@ -1,19 +1,20 @@
 using Musify.Domain.ValueObjects;
 using Xunit;
 
-namespace Musify.Domain.Tests.ValueObjects;
-
-public sealed class TrackPicturesTests
+namespace Musify.Domain.Tests.ValueObjects
 {
-    [Theory]
-    [InlineData(ProcessingStatus.Pending, false)]
-    [InlineData(ProcessingStatus.Processing, false)]
-    [InlineData(ProcessingStatus.Completed, true)]
-    [InlineData(ProcessingStatus.Failed, false)]
-    public void IsProcessed_ReflectsProcessingStatus(ProcessingStatus status, bool expected)
+    public sealed class TrackPicturesTests
     {
-        var pictures = new TrackPictures { ProcessingStatus = status };
+        [Theory]
+        [InlineData(ProcessingStatus.Pending, false)]
+        [InlineData(ProcessingStatus.Processing, false)]
+        [InlineData(ProcessingStatus.Completed, true)]
+        [InlineData(ProcessingStatus.Failed, false)]
+        public void IsProcessed_ReflectsProcessingStatus(ProcessingStatus status, bool expected)
+        {
+            var pictures = new TrackPictures { ProcessingStatus = status };
 
-        Assert.Equal(expected, pictures.IsProcessed);
+            Assert.Equal(expected, pictures.IsProcessed);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Persistence/AuditableEntityInterceptorTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Persistence/AuditableEntityInterceptorTests.cs
index ff74c7c..d4ae5ac 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Persistence/AuditableEntityInterceptorTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Persistence/AuditableEntityInterceptorTests.cs
@@ -2,44 +2,45 @@ using Musify.Domain.Entities;
 using Musify.Infrastructure.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Persistence;
-
-[Collection(InfrastructureCollection.Name)]
-public sealed class AuditableEntityInterceptorTests(InfrastructureTestFixture fixture)
+namespace Musify.Infrastructure.Tests.Persistence
 {
-    [Fact]
-    public async Task SavingChanges_NewEntity_SetsCreatedAtAndUpdatedAtToNow()
+    [Collection(InfrastructureCollection.Name)]
+    public sealed class AuditableEntityInterceptorTests(InfrastructureTestFixture fixture)
     {
-        await using var database = fixture.CreateDatabase();
-        var before = DateTime.UtcNow;
+        [Fact]
+        public async Task SavingChanges_NewEntity_SetsCreatedAtAndUpdatedAtToNow()
+        {
+            await using var database = fixture.CreateDatabase();
+            var before = DateTime.UtcNow;
 
-        var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "audit-user", NormalizedName = "AUDIT-USER" };
-        await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+            var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "audit-user", NormalizedName = "AUDIT-USER" };
+            await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
 
-        var after = DateTime.UtcNow;
+            var after = DateTime.UtcNow;
 
-        Assert.InRange(user.CreatedAt, before, after);
-        Assert.InRange(user.UpdatedAt, before, after);
-    }
+            Assert.InRange(user.CreatedAt, before, after);
+            Assert.InRange(user.UpdatedAt, before, after);
+        }
 
-    [Fact]
-    public async Task SavingChanges_ModifiedEntity_BumpsUpdatedAtButKeepsCreatedAt()
-    {
-        await using var database = fixture.CreateDatabase();
+        [Fact]
+        public async Task SavingChanges_ModifiedEntity_BumpsUpdatedAtButKeepsCreatedAt()
+        {
+            await using var database = fixture.CreateDatabase();
 
-        var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "audit-user-2", NormalizedName = "AUDIT-USER-2" };
-        await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
-        var originalCreatedAt = user.CreatedAt;
+            var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "audit-user-2", NormalizedName = "AUDIT-USER-2" };
+            await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+            var originalCreatedAt = user.CreatedAt;
 
-        await Task.Delay(TimeSpan.FromMilliseconds(50), TestContext.Current.CancellationToken);
+            await Task.Delay(TimeSpan.FromMilliseconds(50), TestContext.Current.CancellationToken);
 
-        user.Name = "audit-user-2-renamed";
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+            user.Name = "audit-user-2-renamed";
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
 
-        Assert.Equal(originalCreatedAt, user.CreatedAt);
-        Assert.True(user.UpdatedAt > originalCreatedAt,
-            $"original-created-at={originalCreatedAt:O}, final-updated-at={user.UpdatedAt:O}");
+            Assert.Equal(originalCreatedAt, user.CreatedAt);
+            Assert.True(user.UpdatedAt > originalCreatedAt,
+                $"original-created-at={originalCreatedAt:O}, final-updated-at={user.UpdatedAt:O}");
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Persistence/DatabaseTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Persistence/DatabaseTests.cs
index 772da33..6de31d1 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Persistence/DatabaseTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Persistence/DatabaseTests.cs
@@ -4,88 +4,89 @@ using Musify.Domain.ValueObjects;
 using Musify.Infrastructure.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Persistence;
-
-[Collection(InfrastructureCollection.Name)]
-public sealed class DatabaseTests(InfrastructureTestFixture fixture)
+namespace Musify.Infrastructure.Tests.Persistence
 {
-    [Fact]
-    public async Task SaveChangesAsync_LocalTrackWithOwnedTypes_RoundTripsThroughPostgres()
+    [Collection(InfrastructureCollection.Name)]
+    public sealed class DatabaseTests(InfrastructureTestFixture fixture)
     {
-        await using var database = fixture.CreateDatabase();
-
-        var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "roundtrip-user", NormalizedName = "ROUNDTRIP-USER" };
-        await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
-
-        var track = new LocalTrack
+        [Fact]
+        public async Task SaveChangesAsync_LocalTrackWithOwnedTypes_RoundTripsThroughPostgres()
         {
-            Title = "Round Trip Track",
-            NormalizedTitle = "ROUND TRIP TRACK",
-            DurationSeconds = 123.4,
-            OwnerUserId = user.Id,
-            Owner = user,
-            Pictures = new TrackPictures { OriginalName = "cover.webp", ProcessingStatus = ProcessingStatus.Pending },
-            Audio = new TrackAudio { OriginalName = "song.mp3", TranscodeStatus = ProcessingStatus.Pending }
+            await using var database = fixture.CreateDatabase();
+
+            var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "roundtrip-user", NormalizedName = "ROUNDTRIP-USER" };
+            await database.Users.AddAsync(user, TestContext.Current.CancellationToken);
+
+            var track = new LocalTrack
+            {
+                Title = "Round Trip Track",
+                NormalizedTitle = "ROUND TRIP TRACK",
+                DurationSeconds = 123.4,
+                OwnerUserId = user.Id,
+                Owner = user,
+                Pictures = new TrackPictures { OriginalName = "cover.webp", ProcessingStatus = ProcessingStatus.Pending },
+                Audio = new TrackAudio { OriginalName = "song.mp3", TranscodeStatus = ProcessingStatus.Pending }
+            };
+            await database.LocalTracks.AddAsync(track, TestContext.Current.CancellationToken);
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+
+            await using var reloaded = fixture.CreateDatabase();
+            var stored = await reloaded.Tracks.AsNoTracking().SingleAsync(t => t.Id == track.Id, TestContext.Current.CancellationToken);
+
+            Assert.IsType<LocalTrack>(stored);
+            Assert.Equal("Round Trip Track", stored.Title);
+            Assert.Equal("cover.webp", stored.Pictures.OriginalName);
+            Assert.Equal("song.mp3", stored.Audio.OriginalName);
+            Assert.Equal(user.Id, ((LocalTrack)stored).OwnerUserId);
+        }
+
+        [Fact]
+        public async Task ExternalTracks_SourceAndExternalIdUniqueIndex_RejectsDuplicates()
+        {
+            await using var database = fixture.CreateDatabase();
+
+            var videoId = $"dup-{Guid.NewGuid():N}";
+            await database.ExternalTracks.AddAsync(BuildExternalTrack(videoId), TestContext.Current.CancellationToken);
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+
+            await using var second = fixture.CreateDatabase();
+            await second.ExternalTracks.AddAsync(BuildExternalTrack(videoId), TestContext.Current.CancellationToken);
+
+            await Assert.ThrowsAsync<DbUpdateException>(() => second.SaveChangesAsync(TestContext.Current.CancellationToken));
+        }
+
+        [Fact]
+        public async Task AlbumHasTracks_DeletingAlbum_CascadesToTheLinkRows()
+        {
+            await using var database = fixture.CreateDatabase();
+
+            var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "cascade-user", NormalizedName = "CASCADE-USER" };
+            var album = new UserAlbum { Title = "Cascade Album", NormalizedTitle = "CASCADE ALBUM", OwnerUserId = user.Id };
+            var track = BuildExternalTrack($"cascade-{Guid.NewGuid():N}");
+            var link = new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 };
+
+            await database.AddRangeAsync(user, album, track, link);
+            await database.SaveChangesAsync(TestContext.Current.CancellationToken);
+
+            await using var deleter = fixture.CreateDatabase();
+            var albumToDelete = await deleter.UserAlbums.SingleAsync(a => a.Id == album.Id, TestContext.Current.CancellationToken);
+            deleter.UserAlbums.Remove(albumToDelete);
+            await deleter.SaveChangesAsync(TestContext.Current.CancellationToken);
+
+            await using var verifier = fixture.CreateDatabase();
+            Assert.False(await verifier.AlbumHasTracks.AnyAsync(l => l.AlbumId == album.Id, TestContext.Current.CancellationToken));
+            Assert.True(await verifier.ExternalTracks.AnyAsync(t => t.Id == track.Id, TestContext.Current.CancellationToken));
+        }
+
+        private static ExternalTrack BuildExternalTrack(string externalId) => new()
+        {
+            Title = "External",
+            NormalizedTitle = "EXTERNAL",
+            DurationSeconds = 100,
+            Source = TrackSource.YouTube,
+            ExternalId = externalId,
+            Pictures = new TrackPictures(),
+            Audio = new TrackAudio()
         };
-        await database.LocalTracks.AddAsync(track, TestContext.Current.CancellationToken);
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
-
-        await using var reloaded = fixture.CreateDatabase();
-        var stored = await reloaded.Tracks.AsNoTracking().SingleAsync(t => t.Id == track.Id, TestContext.Current.CancellationToken);
-
-        Assert.IsType<LocalTrack>(stored);
-        Assert.Equal("Round Trip Track", stored.Title);
-        Assert.Equal("cover.webp", stored.Pictures.OriginalName);
-        Assert.Equal("song.mp3", stored.Audio.OriginalName);
-        Assert.Equal(user.Id, ((LocalTrack)stored).OwnerUserId);
     }
-
-    [Fact]
-    public async Task ExternalTracks_SourceAndExternalIdUniqueIndex_RejectsDuplicates()
-    {
-        await using var database = fixture.CreateDatabase();
-
-        var videoId = $"dup-{Guid.NewGuid():N}";
-        await database.ExternalTracks.AddAsync(BuildExternalTrack(videoId), TestContext.Current.CancellationToken);
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
-
-        await using var second = fixture.CreateDatabase();
-        await second.ExternalTracks.AddAsync(BuildExternalTrack(videoId), TestContext.Current.CancellationToken);
-
-        await Assert.ThrowsAsync<DbUpdateException>(() => second.SaveChangesAsync(TestContext.Current.CancellationToken));
-    }
-
-    [Fact]
-    public async Task AlbumHasTracks_DeletingAlbum_CascadesToTheLinkRows()
-    {
-        await using var database = fixture.CreateDatabase();
-
-        var user = new User { Id = Random.Shared.NextInt64(1, long.MaxValue), Name = "cascade-user", NormalizedName = "CASCADE-USER" };
-        var album = new UserAlbum { Title = "Cascade Album", NormalizedTitle = "CASCADE ALBUM", OwnerUserId = user.Id };
-        var track = BuildExternalTrack($"cascade-{Guid.NewGuid():N}");
-        var link = new AlbumHasTrack { AlbumId = album.Id, TrackId = track.Id, TrackNumber = 1 };
-
-        await database.AddRangeAsync(user, album, track, link);
-        await database.SaveChangesAsync(TestContext.Current.CancellationToken);
-
-        await using var deleter = fixture.CreateDatabase();
-        var albumToDelete = await deleter.UserAlbums.SingleAsync(a => a.Id == album.Id, TestContext.Current.CancellationToken);
-        deleter.UserAlbums.Remove(albumToDelete);
-        await deleter.SaveChangesAsync(TestContext.Current.CancellationToken);
-
-        await using var verifier = fixture.CreateDatabase();
-        Assert.False(await verifier.AlbumHasTracks.AnyAsync(l => l.AlbumId == album.Id, TestContext.Current.CancellationToken));
-        Assert.True(await verifier.ExternalTracks.AnyAsync(t => t.Id == track.Id, TestContext.Current.CancellationToken));
-    }
-
-    private static ExternalTrack BuildExternalTrack(string externalId) => new()
-    {
-        Title = "External",
-        NormalizedTitle = "EXTERNAL",
-        DurationSeconds = 100,
-        Source = TrackSource.YouTube,
-        ExternalId = externalId,
-        Pictures = new TrackPictures(),
-        Audio = new TrackAudio()
-    };
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/DisabledYouTubeMusicServiceTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/DisabledYouTubeMusicServiceTests.cs
index 6ef3286..632b041 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/DisabledYouTubeMusicServiceTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/DisabledYouTubeMusicServiceTests.cs
@@ -2,57 +2,58 @@ using ErrorOr;
 using Musify.Infrastructure.Services;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-public sealed class DisabledYouTubeMusicServiceTests
+namespace Musify.Infrastructure.Tests.Services
 {
-    private readonly DisabledYouTubeMusicService service = new();
-
-    [Fact]
-    public async Task SearchSongsAsync_ReturnsForbidden()
+    public sealed class DisabledYouTubeMusicServiceTests
     {
-        var result = await service.SearchSongsAsync("query", string.Empty, TestContext.Current.CancellationToken);
+        private readonly DisabledYouTubeMusicService service = new();
 
-        Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task SearchSongsAsync_ReturnsForbidden()
+        {
+            var result = await service.SearchSongsAsync("query", string.Empty, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task SearchAlbumsAsync_ReturnsForbidden()
-    {
-        var result = await service.SearchAlbumsAsync("query", string.Empty, TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task SearchAlbumsAsync_ReturnsForbidden()
+        {
+            var result = await service.SearchAlbumsAsync("query", string.Empty, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task GetAlbumAsync_ReturnsForbidden()
-    {
-        var result = await service.GetAlbumAsync("album-1", TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task GetAlbumAsync_ReturnsForbidden()
+        {
+            var result = await service.GetAlbumAsync("album-1", TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task GetAudioStreamAsync_ReturnsForbidden()
-    {
-        var result = await service.GetAudioStreamAsync("video-1", TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task GetAudioStreamAsync_ReturnsForbidden()
+        {
+            var result = await service.GetAudioStreamAsync("video-1", TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task GetSongAsync_ReturnsForbidden()
-    {
-        var result = await service.GetSongAsync("video-1", TestContext.Current.CancellationToken);
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+        }
 
-        Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
-    }
+        [Fact]
+        public async Task GetSongAsync_ReturnsForbidden()
+        {
+            var result = await service.GetSongAsync("video-1", TestContext.Current.CancellationToken);
 
-    [Fact]
-    public void ResolveArtworkUrl_ReturnsTheUrlUnchanged()
-    {
-        var result = service.ResolveArtworkUrl("https://img.example/thumb.jpg");
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+        }
 
-        Assert.Equal("https://img.example/thumb.jpg", result);
+        [Fact]
+        public void ResolveArtworkUrl_ReturnsTheUrlUnchanged()
+        {
+            var result = service.ResolveArtworkUrl("https://img.example/thumb.jpg");
+
+            Assert.Equal("https://img.example/thumb.jpg", result);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/PictureServiceTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/PictureServiceTests.cs
index bf893c8..7b0f086 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/PictureServiceTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/PictureServiceTests.cs
@@ -4,54 +4,55 @@ using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-public sealed class PictureServiceTests
+namespace Musify.Infrastructure.Tests.Services
 {
-    private static PictureService CreateService() => new(NullLogger<PictureService>.Instance);
-
-    private static MemoryStream CreateSourceImage(int width, int height)
+    public sealed class PictureServiceTests
     {
-        using var image = new Image<Rgba32>(width, height, new Rgba32(255, 0, 0));
-        var stream = new MemoryStream();
-        image.SaveAsPng(stream);
-        stream.Position = 0;
-        return stream;
-    }
+        private static PictureService CreateService() => new(NullLogger<PictureService>.Instance);
 
-    [Fact]
-    public async Task ResizePictureAsWebpAsync_LargerThanTarget_ShrinksToFitWithinTheRequestedBox()
-    {
-        using var source = CreateSourceImage(800, 600);
+        private static MemoryStream CreateSourceImage(int width, int height)
+        {
+            using var image = new Image<Rgba32>(width, height, new Rgba32(255, 0, 0));
+            var stream = new MemoryStream();
+            image.SaveAsPng(stream);
+            stream.Position = 0;
+            return stream;
+        }
 
-        await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 200, 200, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task ResizePictureAsWebpAsync_LargerThanTarget_ShrinksToFitWithinTheRequestedBox()
+        {
+            using var source = CreateSourceImage(800, 600);
 
-        using var result = await Image.LoadAsync(resized, TestContext.Current.CancellationToken);
-        Assert.InRange(result.Width, 1, 200);
-        Assert.InRange(result.Height, 1, 200);
-        Assert.True(result.Width == 200 || result.Height == 200, "expected the longer side to land exactly on the target box");
-    }
+            await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 200, 200, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task ResizePictureAsWebpAsync_ReturnsAValidWebpStream()
-    {
-        using var source = CreateSourceImage(100, 100);
+            using var result = await Image.LoadAsync(resized, TestContext.Current.CancellationToken);
+            Assert.InRange(result.Width, 1, 200);
+            Assert.InRange(result.Height, 1, 200);
+            Assert.True(result.Width == 200 || result.Height == 200, "expected the longer side to land exactly on the target box");
+        }
 
-        await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 50, 50, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task ResizePictureAsWebpAsync_ReturnsAValidWebpStream()
+        {
+            using var source = CreateSourceImage(100, 100);
 
-        var format = await Image.DetectFormatAsync(resized, TestContext.Current.CancellationToken);
-        Assert.Equal("WEBP", format?.Name, ignoreCase: true);
-    }
+            await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 50, 50, TestContext.Current.CancellationToken);
 
-    [Fact]
-    public async Task ResizePictureAsWebpAsync_PreservesAspectRatio()
-    {
-        using var source = CreateSourceImage(400, 200);
+            var format = await Image.DetectFormatAsync(resized, TestContext.Current.CancellationToken);
+            Assert.Equal("WEBP", format?.Name, ignoreCase: true);
+        }
 
-        await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 100, 100, TestContext.Current.CancellationToken);
+        [Fact]
+        public async Task ResizePictureAsWebpAsync_PreservesAspectRatio()
+        {
+            using var source = CreateSourceImage(400, 200);
 
-        using var result = await Image.LoadAsync(resized, TestContext.Current.CancellationToken);
-        Assert.Equal(100, result.Width);
-        Assert.Equal(50, result.Height);
+            await using var resized = await CreateService().ResizePictureAsWebpAsync(source, 100, 100, TestContext.Current.CancellationToken);
+
+            using var result = await Image.LoadAsync(resized, TestContext.Current.CancellationToken);
+            Assert.Equal(100, result.Width);
+            Assert.Equal(50, result.Height);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/PlayListPresetSeederTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/PlayListPresetSeederTests.cs
index acd4d9c..6cbcfb3 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/PlayListPresetSeederTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/PlayListPresetSeederTests.cs
@@ -7,96 +7,97 @@ using Musify.Infrastructure.Services;
 using Musify.Infrastructure.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-[Collection(InfrastructureCollection.Name)]
-public sealed class PlayListPresetSeederTests(InfrastructureTestFixture fixture)
+namespace Musify.Infrastructure.Tests.Services
 {
-    private static PlayListConfiguration NewConfiguration(bool overwritePresetPictures) => new()
+    [Collection(InfrastructureCollection.Name)]
+    public sealed class PlayListPresetSeederTests(InfrastructureTestFixture fixture)
     {
-        Routes = new PlayListRoutes { ParentFolders = $"PlayLists-{Guid.NewGuid():N}" },
-        SeedPresetPictures = true,
-        OverwritePresetPictures = overwritePresetPictures
-    };
-
-    private (PlayListPresetSeeder Seeder, IStorageService Storage) Build(PlayListConfiguration configuration)
-    {
-        var services = new ServiceCollection();
-        services.AddSingleton(configuration);
-        services.AddSingleton(new ApplicationStorageConfiguration { Bucket = InfrastructureTestFixture.S3Bucket });
-        services.AddSingleton<IStorageService>(_ => new StorageService(
-            fixture.CreateDatabase(),
-            fixture.CreateS3Client(),
-            NullLogger<StorageService>.Instance,
-            new InfrastructureStorageConfiguration
-            {
-                Address = fixture.S3ServiceUrl,
-                AccessKey = InfrastructureTestFixture.S3AccessKey,
-                SecretAccessKey = InfrastructureTestFixture.S3SecretKey,
-                ForcePathStyle = true,
-                UseHttp = true,
-            }));
-        services.AddSingleton<IPictureService>(new PictureService(NullLogger<PictureService>.Instance));
-
-        var provider = services.BuildServiceProvider();
-        var seeder = new PlayListPresetSeeder(provider.GetRequiredService<IServiceScopeFactory>(), NullLogger<PlayListPresetSeeder>.Instance);
-        return (seeder, provider.GetRequiredService<IStorageService>());
-    }
-
-    private static async Task RunToCompletionAsync(PlayListPresetSeeder seeder)
-    {
-        await seeder.StartAsync(TestContext.Current.CancellationToken);
-        await (seeder.ExecuteTask ?? Task.CompletedTask);
-    }
-
-    [Fact]
-    public async Task ExecuteAsync_SeedsAllFourPresetPictures()
-    {
-        var configuration = NewConfiguration(overwritePresetPictures: false);
-        var (seeder, storage) = Build(configuration);
-
-        await RunToCompletionAsync(seeder);
-
-        var routes = configuration.Routes;
-        foreach (var key in new[]
-                 {
-                     routes.BuildOriginalPicturePath(routes.PresetOriginalPicture),
-                     routes.PresetSmallPicturePath,
-                     routes.PresetMediumPicturePath,
-                     routes.PresetLargePicturePath
-                 })
+        private static PlayListConfiguration NewConfiguration(bool overwritePresetPictures) => new()
         {
-            var metadata = await storage.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-            Assert.True(metadata is not null, $"expected {key} to have been seeded");
+            Routes = new PlayListRoutes { ParentFolders = $"PlayLists-{Guid.NewGuid():N}" },
+            SeedPresetPictures = true,
+            OverwritePresetPictures = overwritePresetPictures
+        };
+
+        private (PlayListPresetSeeder Seeder, IStorageService Storage) Build(PlayListConfiguration configuration)
+        {
+            var services = new ServiceCollection();
+            services.AddSingleton(configuration);
+            services.AddSingleton(new ApplicationStorageConfiguration { Bucket = InfrastructureTestFixture.S3Bucket });
+            services.AddSingleton<IStorageService>(_ => new StorageService(
+                fixture.CreateDatabase(),
+                fixture.CreateS3Client(),
+                NullLogger<StorageService>.Instance,
+                new InfrastructureStorageConfiguration
+                {
+                    Address = fixture.S3ServiceUrl,
+                    AccessKey = InfrastructureTestFixture.S3AccessKey,
+                    SecretAccessKey = InfrastructureTestFixture.S3SecretKey,
+                    ForcePathStyle = true,
+                    UseHttp = true,
+                }));
+            services.AddSingleton<IPictureService>(new PictureService(NullLogger<PictureService>.Instance));
+
+            var provider = services.BuildServiceProvider();
+            var seeder = new PlayListPresetSeeder(provider.GetRequiredService<IServiceScopeFactory>(), NullLogger<PlayListPresetSeeder>.Instance);
+            return (seeder, provider.GetRequiredService<IStorageService>());
+        }
+
+        private static async Task RunToCompletionAsync(PlayListPresetSeeder seeder)
+        {
+            await seeder.StartAsync(TestContext.Current.CancellationToken);
+            await (seeder.ExecuteTask ?? Task.CompletedTask);
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_SeedsAllFourPresetPictures()
+        {
+            var configuration = NewConfiguration(overwritePresetPictures: false);
+            var (seeder, storage) = Build(configuration);
+
+            await RunToCompletionAsync(seeder);
+
+            var routes = configuration.Routes;
+            foreach (var key in new[]
+                     {
+                         routes.BuildOriginalPicturePath(routes.PresetOriginalPicture),
+                         routes.PresetSmallPicturePath,
+                         routes.PresetMediumPicturePath,
+                         routes.PresetLargePicturePath
+                     })
+            {
+                var metadata = await storage.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+                Assert.True(metadata is not null, $"expected {key} to have been seeded");
+            }
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_RunTwiceWithoutOverwrite_StaysIdempotent()
+        {
+            var configuration = NewConfiguration(overwritePresetPictures: false);
+            var (firstSeeder, storage) = Build(configuration);
+            await RunToCompletionAsync(firstSeeder);
+
+            var (secondSeeder, _) = Build(configuration);
+            await RunToCompletionAsync(secondSeeder);
+
+            var metadata = await storage.HeadObjectAsync(
+                InfrastructureTestFixture.S3Bucket, configuration.Routes.PresetSmallPicturePath, TestContext.Current.CancellationToken);
+            Assert.NotNull(metadata);
+        }
+
+        [Fact]
+        public async Task ExecuteAsync_SeedPresetPicturesDisabled_UploadsNothing()
+        {
+            var configuration = NewConfiguration(overwritePresetPictures: false);
+            configuration.SeedPresetPictures = false;
+            var (seeder, storage) = Build(configuration);
+
+            await RunToCompletionAsync(seeder);
+
+            var metadata = await storage.HeadObjectAsync(
+                InfrastructureTestFixture.S3Bucket, configuration.Routes.PresetSmallPicturePath, TestContext.Current.CancellationToken);
+            Assert.Null(metadata);
         }
     }
-
-    [Fact]
-    public async Task ExecuteAsync_RunTwiceWithoutOverwrite_StaysIdempotent()
-    {
-        var configuration = NewConfiguration(overwritePresetPictures: false);
-        var (firstSeeder, storage) = Build(configuration);
-        await RunToCompletionAsync(firstSeeder);
-
-        var (secondSeeder, _) = Build(configuration);
-        await RunToCompletionAsync(secondSeeder);
-
-        var metadata = await storage.HeadObjectAsync(
-            InfrastructureTestFixture.S3Bucket, configuration.Routes.PresetSmallPicturePath, TestContext.Current.CancellationToken);
-        Assert.NotNull(metadata);
-    }
-
-    [Fact]
-    public async Task ExecuteAsync_SeedPresetPicturesDisabled_UploadsNothing()
-    {
-        var configuration = NewConfiguration(overwritePresetPictures: false);
-        configuration.SeedPresetPictures = false;
-        var (seeder, storage) = Build(configuration);
-
-        await RunToCompletionAsync(seeder);
-
-        var metadata = await storage.HeadObjectAsync(
-            InfrastructureTestFixture.S3Bucket, configuration.Routes.PresetSmallPicturePath, TestContext.Current.CancellationToken);
-        Assert.Null(metadata);
-    }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/SingleFlightCacheTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/SingleFlightCacheTests.cs
index da41272..50d7158 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/SingleFlightCacheTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/SingleFlightCacheTests.cs
@@ -3,78 +3,79 @@ using Microsoft.Extensions.Caching.Memory;
 using Musify.Infrastructure.Services;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-public sealed class SingleFlightCacheTests
+namespace Musify.Infrastructure.Tests.Services
 {
-    private static SingleFlightCache CreateCache() => new(new MemoryCache(new MemoryCacheOptions()));
-
-    [Fact]
-    public async Task GetOrCreateAsync_SecondCallWithinDuration_ReturnsCachedValueWithoutCallingFactory()
+    public sealed class SingleFlightCacheTests
     {
-        var cache = CreateCache();
-        var calls = 0;
-        Task<ErrorOr<int>> Factory() { calls++; return Task.FromResult<ErrorOr<int>>(calls); }
+        private static SingleFlightCache CreateCache() => new(new MemoryCache(new MemoryCacheOptions()));
 
-        var first = await cache.GetOrCreateAsync("key", TimeSpan.FromMinutes(1), Factory);
-        var second = await cache.GetOrCreateAsync("key", TimeSpan.FromMinutes(1), Factory);
-
-        Assert.Equal(1, first.Value);
-        Assert.Equal(1, second.Value);
-        Assert.Equal(1, calls);
-    }
-
-    [Fact]
-    public async Task GetOrCreateAsync_ConcurrentCallsForTheSameKey_CollapseIntoASingleFactoryCall()
-    {
-        var cache = CreateCache();
-        var calls = 0;
-        var gate = new TaskCompletionSource();
-
-        async Task<ErrorOr<int>> Factory()
+        [Fact]
+        public async Task GetOrCreateAsync_SecondCallWithinDuration_ReturnsCachedValueWithoutCallingFactory()
         {
-            Interlocked.Increment(ref calls);
-            await gate.Task;
-            return 7;
+            var cache = CreateCache();
+            var calls = 0;
+            Task<ErrorOr<int>> Factory() { calls++; return Task.FromResult<ErrorOr<int>>(calls); }
+
+            var first = await cache.GetOrCreateAsync("key", TimeSpan.FromMinutes(1), Factory);
+            var second = await cache.GetOrCreateAsync("key", TimeSpan.FromMinutes(1), Factory);
+
+            Assert.Equal(1, first.Value);
+            Assert.Equal(1, second.Value);
+            Assert.Equal(1, calls);
         }
 
-        var first = cache.GetOrCreateAsync("concurrent-key", TimeSpan.FromMinutes(1), Factory);
-        var second = cache.GetOrCreateAsync("concurrent-key", TimeSpan.FromMinutes(1), Factory);
-        gate.SetResult();
-
-        var results = await Task.WhenAll(first, second);
-
-        Assert.Equal(1, calls);
-        Assert.All(results, result => Assert.Equal(7, result.Value));
-    }
-
-    [Fact]
-    public async Task GetOrCreateAsync_FactoryReturnsError_DoesNotCacheIt()
-    {
-        var cache = CreateCache();
-        var calls = 0;
-        Task<ErrorOr<int>> Factory()
+        [Fact]
+        public async Task GetOrCreateAsync_ConcurrentCallsForTheSameKey_CollapseIntoASingleFactoryCall()
         {
-            calls++;
-            return Task.FromResult<ErrorOr<int>>(Error.Failure(description: "boom"));
+            var cache = CreateCache();
+            var calls = 0;
+            var gate = new TaskCompletionSource();
+
+            async Task<ErrorOr<int>> Factory()
+            {
+                Interlocked.Increment(ref calls);
+                await gate.Task;
+                return 7;
+            }
+
+            var first = cache.GetOrCreateAsync("concurrent-key", TimeSpan.FromMinutes(1), Factory);
+            var second = cache.GetOrCreateAsync("concurrent-key", TimeSpan.FromMinutes(1), Factory);
+            gate.SetResult();
+
+            var results = await Task.WhenAll(first, second);
+
+            Assert.Equal(1, calls);
+            Assert.All(results, result => Assert.Equal(7, result.Value));
         }
 
-        await cache.GetOrCreateAsync("error-key", TimeSpan.FromMinutes(1), Factory);
-        await cache.GetOrCreateAsync("error-key", TimeSpan.FromMinutes(1), Factory);
+        [Fact]
+        public async Task GetOrCreateAsync_FactoryReturnsError_DoesNotCacheIt()
+        {
+            var cache = CreateCache();
+            var calls = 0;
+            Task<ErrorOr<int>> Factory()
+            {
+                calls++;
+                return Task.FromResult<ErrorOr<int>>(Error.Failure(description: "boom"));
+            }
 
-        Assert.Equal(2, calls);
-    }
+            await cache.GetOrCreateAsync("error-key", TimeSpan.FromMinutes(1), Factory);
+            await cache.GetOrCreateAsync("error-key", TimeSpan.FromMinutes(1), Factory);
 
-    [Fact]
-    public async Task GetOrCreateAsync_NonPositiveDuration_AlwaysCallsTheFactory()
-    {
-        var cache = CreateCache();
-        var calls = 0;
-        Task<ErrorOr<int>> Factory() { calls++; return Task.FromResult<ErrorOr<int>>(calls); }
+            Assert.Equal(2, calls);
+        }
 
-        await cache.GetOrCreateAsync("no-cache-key", TimeSpan.Zero, Factory);
-        await cache.GetOrCreateAsync("no-cache-key", TimeSpan.Zero, Factory);
+        [Fact]
+        public async Task GetOrCreateAsync_NonPositiveDuration_AlwaysCallsTheFactory()
+        {
+            var cache = CreateCache();
+            var calls = 0;
+            Task<ErrorOr<int>> Factory() { calls++; return Task.FromResult<ErrorOr<int>>(calls); }
 
-        Assert.Equal(2, calls);
+            await cache.GetOrCreateAsync("no-cache-key", TimeSpan.Zero, Factory);
+            await cache.GetOrCreateAsync("no-cache-key", TimeSpan.Zero, Factory);
+
+            Assert.Equal(2, calls);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/StorageServiceTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/StorageServiceTests.cs
index 9b606e4..5cc045c 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/StorageServiceTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/StorageServiceTests.cs
@@ -8,144 +8,145 @@ using Musify.Infrastructure.Services;
 using Musify.Infrastructure.Tests.TestSupport;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-[Collection(InfrastructureCollection.Name)]
-public sealed class StorageServiceTests(InfrastructureTestFixture fixture) : IAsyncLifetime
+namespace Musify.Infrastructure.Tests.Services
 {
-    private Database database = null!;
-    private StorageService service = null!;
-
-    public ValueTask InitializeAsync()
+    [Collection(InfrastructureCollection.Name)]
+    public sealed class StorageServiceTests(InfrastructureTestFixture fixture) : IAsyncLifetime
     {
-        database = fixture.CreateDatabase();
-        var storageConfiguration = new InfrastructureStorageConfiguration
+        private Database database = null!;
+        private StorageService service = null!;
+
+        public ValueTask InitializeAsync()
         {
-            Address = fixture.S3ServiceUrl,
-            AccessKey = InfrastructureTestFixture.S3AccessKey,
-            SecretAccessKey = InfrastructureTestFixture.S3SecretKey,
-            ForcePathStyle = true,
-            UseHttp = true,
-        };
-        service = new StorageService(database, fixture.CreateS3Client(), NullLogger<StorageService>.Instance, storageConfiguration);
-        return ValueTask.CompletedTask;
-    }
+            database = fixture.CreateDatabase();
+            var storageConfiguration = new InfrastructureStorageConfiguration
+            {
+                Address = fixture.S3ServiceUrl,
+                AccessKey = InfrastructureTestFixture.S3AccessKey,
+                SecretAccessKey = InfrastructureTestFixture.S3SecretKey,
+                ForcePathStyle = true,
+                UseHttp = true,
+            };
+            service = new StorageService(database, fixture.CreateS3Client(), NullLogger<StorageService>.Instance, storageConfiguration);
+            return ValueTask.CompletedTask;
+        }
 
-    public ValueTask DisposeAsync() => database.DisposeAsync();
+        public ValueTask DisposeAsync() => database.DisposeAsync();
 
-    [Fact]
-    public async Task UploadThenGetFile_RoundTripsTheSameBytes()
-    {
-        var key = $"tests/{Guid.NewGuid():N}/round-trip.txt";
-        var content = "hello seaweedfs"u8.ToArray();
-
-        await service.UploadFileAsync(new MemoryStream(content), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-
-        await using var stream = await service.GetFileAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-        using var reader = new StreamReader(stream, Encoding.UTF8);
-        var readBack = await reader.ReadToEndAsync(TestContext.Current.CancellationToken);
-
-        Assert.Equal("hello seaweedfs", readBack);
-    }
-
-    [Fact]
-    public async Task HeadObjectAsync_ExistingObject_ReturnsMetadata()
-    {
-        var key = $"tests/{Guid.NewGuid():N}/head.txt";
-        await service.UploadFileAsync(new MemoryStream("x"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-
-        var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-
-        Assert.NotNull(metadata);
-        Assert.Equal(1, metadata.ContentLength);
-    }
-
-    [Fact]
-    public async Task HeadObjectAsync_MissingObject_ReturnsNull()
-    {
-        var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, $"tests/{Guid.NewGuid():N}/missing.txt", TestContext.Current.CancellationToken);
-
-        Assert.Null(metadata);
-    }
-
-    [Fact]
-    public async Task RemoveFileAsync_ExistingObject_DeletesIt()
-    {
-        var key = $"tests/{Guid.NewGuid():N}/to-remove.txt";
-        await service.UploadFileAsync(new MemoryStream("x"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-
-        await service.RemoveFileAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-
-        Assert.Null(await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken));
-    }
-
-    [Fact]
-    public async Task CopyFileAsync_CopiesToTheDestinationKey()
-    {
-        var sourceKey = $"tests/{Guid.NewGuid():N}/source.txt";
-        var destinationKey = $"tests/{Guid.NewGuid():N}/destination.txt";
-        await service.UploadFileAsync(new MemoryStream("copy-me"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, sourceKey, TestContext.Current.CancellationToken);
-
-        await service.CopyFileAsync(InfrastructureTestFixture.S3Bucket, sourceKey, InfrastructureTestFixture.S3Bucket, destinationKey, TestContext.Current.CancellationToken);
-
-        Assert.NotNull(await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, destinationKey, TestContext.Current.CancellationToken));
-    }
-
-    [Fact]
-    public async Task ListObjectsAsync_ReturnsEveryObjectUnderThePrefix()
-    {
-        var prefix = $"tests/{Guid.NewGuid():N}";
-        await service.UploadFileAsync(new MemoryStream("a"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/a.txt", TestContext.Current.CancellationToken);
-        await service.UploadFileAsync(new MemoryStream("b"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/b.txt", TestContext.Current.CancellationToken);
-
-        var keys = new List<string>();
-        await foreach (var item in service.ListObjectsAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken))
-            keys.Add(item.Key);
-
-        Assert.Equal([$"{prefix}/a.txt", $"{prefix}/b.txt"], keys.Order());
-    }
-
-    [Fact]
-    public async Task RemoveFolderAsync_DeletesEveryObjectUnderThePrefix()
-    {
-        var prefix = $"tests/{Guid.NewGuid():N}";
-        await service.UploadFileAsync(new MemoryStream("a"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/a.txt", TestContext.Current.CancellationToken);
-        await service.UploadFileAsync(new MemoryStream("b"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/nested/b.txt", TestContext.Current.CancellationToken);
-
-        await service.RemoveFolderAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken);
-
-        var remaining = new List<string>();
-        await foreach (var item in service.ListObjectsAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken))
-            remaining.Add(item.Key);
-        Assert.Empty(remaining);
-    }
-
-    [Fact]
-    public async Task GetUploadUrlAsync_PresignedPut_CanActuallyUploadTheObject()
-    {
-        var key = $"tests/{Guid.NewGuid():N}/presigned.txt";
-
-        var uploadUrl = await service.GetUploadUrlAsync(
-            InfrastructureTestFixture.S3Bucket, key, "text/plain", TimeSpan.FromMinutes(5), TestContext.Current.CancellationToken);
-
-        using var httpClient = new HttpClient();
-        using var request = new HttpRequestMessage(HttpMethod.Put, uploadUrl)
+        [Fact]
+        public async Task UploadThenGetFile_RoundTripsTheSameBytes()
         {
-            // Not StringContent: it appends "; charset=utf-8" to Content-Type, which no longer
-            // matches the "text/plain" the presigned URL's signature was computed over (SigV4
-            // signs Content-Type byte-for-byte) and the server answers 403 SignatureDoesNotMatch.
-            Content = new ByteArrayContent(Encoding.UTF8.GetBytes("presigned content"))
-        };
-        request.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
-        // GetUploadUrlAsync defaults preventOverwrite to true, which signs the URL together with
-        // this header (see StorageService.GetUploadUrlAsync) — the actual PUT has to send it too,
-        // or the signature no longer matches and the server answers 403.
-        request.Headers.TryAddWithoutValidation("If-None-Match", "*");
-        var response = await httpClient.SendAsync(request, TestContext.Current.CancellationToken);
+            var key = $"tests/{Guid.NewGuid():N}/round-trip.txt";
+            var content = "hello seaweedfs"u8.ToArray();
 
-        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
-        var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
-        Assert.NotNull(metadata);
-        Assert.Equal("presigned content".Length, metadata.ContentLength);
+            await service.UploadFileAsync(new MemoryStream(content), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+
+            await using var stream = await service.GetFileAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+            using var reader = new StreamReader(stream, Encoding.UTF8);
+            var readBack = await reader.ReadToEndAsync(TestContext.Current.CancellationToken);
+
+            Assert.Equal("hello seaweedfs", readBack);
+        }
+
+        [Fact]
+        public async Task HeadObjectAsync_ExistingObject_ReturnsMetadata()
+        {
+            var key = $"tests/{Guid.NewGuid():N}/head.txt";
+            await service.UploadFileAsync(new MemoryStream("x"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+
+            var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+
+            Assert.NotNull(metadata);
+            Assert.Equal(1, metadata.ContentLength);
+        }
+
+        [Fact]
+        public async Task HeadObjectAsync_MissingObject_ReturnsNull()
+        {
+            var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, $"tests/{Guid.NewGuid():N}/missing.txt", TestContext.Current.CancellationToken);
+
+            Assert.Null(metadata);
+        }
+
+        [Fact]
+        public async Task RemoveFileAsync_ExistingObject_DeletesIt()
+        {
+            var key = $"tests/{Guid.NewGuid():N}/to-remove.txt";
+            await service.UploadFileAsync(new MemoryStream("x"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+
+            await service.RemoveFileAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+
+            Assert.Null(await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken));
+        }
+
+        [Fact]
+        public async Task CopyFileAsync_CopiesToTheDestinationKey()
+        {
+            var sourceKey = $"tests/{Guid.NewGuid():N}/source.txt";
+            var destinationKey = $"tests/{Guid.NewGuid():N}/destination.txt";
+            await service.UploadFileAsync(new MemoryStream("copy-me"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, sourceKey, TestContext.Current.CancellationToken);
+
+            await service.CopyFileAsync(InfrastructureTestFixture.S3Bucket, sourceKey, InfrastructureTestFixture.S3Bucket, destinationKey, TestContext.Current.CancellationToken);
+
+            Assert.NotNull(await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, destinationKey, TestContext.Current.CancellationToken));
+        }
+
+        [Fact]
+        public async Task ListObjectsAsync_ReturnsEveryObjectUnderThePrefix()
+        {
+            var prefix = $"tests/{Guid.NewGuid():N}";
+            await service.UploadFileAsync(new MemoryStream("a"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/a.txt", TestContext.Current.CancellationToken);
+            await service.UploadFileAsync(new MemoryStream("b"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/b.txt", TestContext.Current.CancellationToken);
+
+            var keys = new List<string>();
+            await foreach (var item in service.ListObjectsAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken))
+                keys.Add(item.Key);
+
+            Assert.Equal([$"{prefix}/a.txt", $"{prefix}/b.txt"], keys.Order());
+        }
+
+        [Fact]
+        public async Task RemoveFolderAsync_DeletesEveryObjectUnderThePrefix()
+        {
+            var prefix = $"tests/{Guid.NewGuid():N}";
+            await service.UploadFileAsync(new MemoryStream("a"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/a.txt", TestContext.Current.CancellationToken);
+            await service.UploadFileAsync(new MemoryStream("b"u8.ToArray()), "text/plain", InfrastructureTestFixture.S3Bucket, $"{prefix}/nested/b.txt", TestContext.Current.CancellationToken);
+
+            await service.RemoveFolderAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken);
+
+            var remaining = new List<string>();
+            await foreach (var item in service.ListObjectsAsync(InfrastructureTestFixture.S3Bucket, prefix, TestContext.Current.CancellationToken))
+                remaining.Add(item.Key);
+            Assert.Empty(remaining);
+        }
+
+        [Fact]
+        public async Task GetUploadUrlAsync_PresignedPut_CanActuallyUploadTheObject()
+        {
+            var key = $"tests/{Guid.NewGuid():N}/presigned.txt";
+
+            var uploadUrl = await service.GetUploadUrlAsync(
+                InfrastructureTestFixture.S3Bucket, key, "text/plain", TimeSpan.FromMinutes(5), TestContext.Current.CancellationToken);
+
+            using var httpClient = new HttpClient();
+            using var request = new HttpRequestMessage(HttpMethod.Put, uploadUrl)
+            {
+                // Not StringContent: it appends "; charset=utf-8" to Content-Type, which no longer
+                // matches the "text/plain" the presigned URL's signature was computed over (SigV4
+                // signs Content-Type byte-for-byte) and the server answers 403 SignatureDoesNotMatch.
+                Content = new ByteArrayContent(Encoding.UTF8.GetBytes("presigned content"))
+            };
+            request.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
+            // GetUploadUrlAsync defaults preventOverwrite to true, which signs the URL together with
+            // this header (see StorageService.GetUploadUrlAsync) — the actual PUT has to send it too,
+            // or the signature no longer matches and the server answers 403.
+            request.Headers.TryAddWithoutValidation("If-None-Match", "*");
+            var response = await httpClient.SendAsync(request, TestContext.Current.CancellationToken);
+
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            var metadata = await service.HeadObjectAsync(InfrastructureTestFixture.S3Bucket, key, TestContext.Current.CancellationToken);
+            Assert.NotNull(metadata);
+            Assert.Equal("presigned content".Length, metadata.ContentLength);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/Services/StreamTicketServiceTests.cs b/backend/Tests/Musify.Infrastructure.Tests/Services/StreamTicketServiceTests.cs
index b701dc9..f233fd3 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/Services/StreamTicketServiceTests.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/Services/StreamTicketServiceTests.cs
@@ -5,67 +5,68 @@ using Musify.Infrastructure.Configuration;
 using Musify.Infrastructure.Services;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.Services;
-
-public sealed class StreamTicketServiceTests : IDisposable
+namespace Musify.Infrastructure.Tests.Services
 {
-    private readonly string privateKeyPath = Path.GetTempFileName();
-    private readonly RSA rsa = RSA.Create(2048);
-
-    public StreamTicketServiceTests() => File.WriteAllText(privateKeyPath, rsa.ExportPkcs8PrivateKeyPem());
-
-    public void Dispose()
+    public sealed class StreamTicketServiceTests : IDisposable
     {
-        rsa.Dispose();
-        File.Delete(privateKeyPath);
-    }
+        private readonly string privateKeyPath = Path.GetTempFileName();
+        private readonly RSA rsa = RSA.Create(2048);
 
-    private StreamTicketService CreateService(int ticketTtlSeconds = 3600) => new(new StreamTicketConfiguration
-    {
-        PrivateKeyPath = privateKeyPath,
-        Audience = "media-gateway",
-        Issuer = "musify-webapi",
-        TicketTtlSeconds = ticketTtlSeconds
-    });
+        public StreamTicketServiceTests() => File.WriteAllText(privateKeyPath, rsa.ExportPkcs8PrivateKeyPem());
 
-    [Fact]
-    public void IssueTicket_ReturnsATokenSignedWithTheConfiguredKeyAndClaims()
-    {
-        using var service = CreateService(ticketTtlSeconds: 120);
-
-        var ticket = service.IssueTicket(userId: 42, keyPrefix: "Tracks/ProcessedAudios/abc/");
-
-        Assert.Equal(120, ticket.ExpiresInSeconds);
-
-        var handler = new JsonWebTokenHandler();
-        var jwt = handler.ReadJsonWebToken(ticket.Token);
-        Assert.Equal("42", jwt.GetClaim("sub").Value);
-        Assert.Equal("Tracks/ProcessedAudios/abc/", jwt.GetClaim("prefix").Value);
-        Assert.Equal("musify-webapi", jwt.Issuer);
-        Assert.Contains("media-gateway", jwt.Audiences);
-    }
-
-    [Fact]
-    public async Task IssueTicket_TokenValidatesAgainstTheMatchingPublicKey()
-    {
-        using var service = CreateService();
-        var ticket = service.IssueTicket(userId: 1, keyPrefix: "Tracks/ProcessedAudios/xyz/");
-
-        var publicKeyPem = rsa.ExportSubjectPublicKeyInfoPem();
-        using var verifyingRsa = RSA.Create();
-        verifyingRsa.ImportFromPem(publicKeyPem);
-
-        var handler = new JsonWebTokenHandler();
-        var result = await handler.ValidateTokenAsync(ticket.Token, new TokenValidationParameters
+        public void Dispose()
         {
-            ValidIssuer = "musify-webapi",
-            ValidAudience = "media-gateway",
-            ValidateIssuer = true,
-            ValidateAudience = true,
-            ValidateLifetime = true,
-            IssuerSigningKey = new RsaSecurityKey(verifyingRsa),
+            rsa.Dispose();
+            File.Delete(privateKeyPath);
+        }
+
+        private StreamTicketService CreateService(int ticketTtlSeconds = 3600) => new(new StreamTicketConfiguration
+        {
+            PrivateKeyPath = privateKeyPath,
+            Audience = "media-gateway",
+            Issuer = "musify-webapi",
+            TicketTtlSeconds = ticketTtlSeconds
         });
 
-        Assert.True(result.IsValid);
+        [Fact]
+        public void IssueTicket_ReturnsATokenSignedWithTheConfiguredKeyAndClaims()
+        {
+            using var service = CreateService(ticketTtlSeconds: 120);
+
+            var ticket = service.IssueTicket(userId: 42, keyPrefix: "Tracks/ProcessedAudios/abc/");
+
+            Assert.Equal(120, ticket.ExpiresInSeconds);
+
+            var handler = new JsonWebTokenHandler();
+            var jwt = handler.ReadJsonWebToken(ticket.Token);
+            Assert.Equal("42", jwt.GetClaim("sub").Value);
+            Assert.Equal("Tracks/ProcessedAudios/abc/", jwt.GetClaim("prefix").Value);
+            Assert.Equal("musify-webapi", jwt.Issuer);
+            Assert.Contains("media-gateway", jwt.Audiences);
+        }
+
+        [Fact]
+        public async Task IssueTicket_TokenValidatesAgainstTheMatchingPublicKey()
+        {
+            using var service = CreateService();
+            var ticket = service.IssueTicket(userId: 1, keyPrefix: "Tracks/ProcessedAudios/xyz/");
+
+            var publicKeyPem = rsa.ExportSubjectPublicKeyInfoPem();
+            using var verifyingRsa = RSA.Create();
+            verifyingRsa.ImportFromPem(publicKeyPem);
+
+            var handler = new JsonWebTokenHandler();
+            var result = await handler.ValidateTokenAsync(ticket.Token, new TokenValidationParameters
+            {
+                ValidIssuer = "musify-webapi",
+                ValidAudience = "media-gateway",
+                ValidateIssuer = true,
+                ValidateAudience = true,
+                ValidateLifetime = true,
+                IssuerSigningKey = new RsaSecurityKey(verifyingRsa),
+            });
+
+            Assert.True(result.IsValid);
+        }
     }
 }
diff --git a/backend/Tests/Musify.Infrastructure.Tests/TestSupport/InfrastructureTestFixture.cs b/backend/Tests/Musify.Infrastructure.Tests/TestSupport/InfrastructureTestFixture.cs
index ae27607..940dfd3 100644
--- a/backend/Tests/Musify.Infrastructure.Tests/TestSupport/InfrastructureTestFixture.cs
+++ b/backend/Tests/Musify.Infrastructure.Tests/TestSupport/InfrastructureTestFixture.cs
@@ -10,108 +10,109 @@ using DotNet.Testcontainers.Builders;
 using DotNet.Testcontainers.Containers;
 using Xunit;
 
-namespace Musify.Infrastructure.Tests.TestSupport;
-
-/// <summary>
-/// One Postgres container and one SeaweedFS container (same image and startup
-/// command as <c>deploy/compose.yml</c>), started once for every test in the
-/// <see cref="InfrastructureCollection"/> and torn down when the run finishes.
-/// EF Core migrations run once here too, against the real <c>Database</c>
-/// DbContext, so a broken migration fails the whole run immediately.
-/// </summary>
-public sealed class InfrastructureTestFixture : IAsyncLifetime
+namespace Musify.Infrastructure.Tests.TestSupport
 {
-    public const string S3AccessKey = "musify-test";
-    public const string S3SecretKey = "musify-test-secret";
-    public const string S3Bucket = "musify-test-bucket";
-
-    private readonly PostgreSqlContainer postgres = new PostgreSqlBuilder("postgres:17-alpine")
-        .WithDatabase("musify_test")
-        .WithUsername("postgres")
-        .WithPassword("postgres")
-        .Build();
-
-    private readonly IContainer seaweedFs = new ContainerBuilder("chrislusf/seaweedfs:latest")
-        .WithEntrypoint("/bin/sh", "-c")
-        .WithCommand(BuildSeaweedFsStartupScript())
-        .WithPortBinding(9333, assignRandomHostPort: true)
-        .WithPortBinding(8333, assignRandomHostPort: true)
-        .WithWaitStrategy(Wait.ForUnixContainer()
-            .UntilHttpRequestIsSucceeded(request => request.ForPort(9333).ForPath("/cluster/healthz")))
-        .Build();
-
-    public string ConnectionString => postgres.GetConnectionString();
-
-    public string S3ServiceUrl => $"http://{seaweedFs.Hostname}:{seaweedFs.GetMappedPublicPort(8333)}";
-
-    public async ValueTask InitializeAsync()
+    /// <summary>
+    /// One Postgres container and one SeaweedFS container (same image and startup
+    /// command as <c>deploy/compose.yml</c>), started once for every test in the
+    /// <see cref="InfrastructureCollection"/> and torn down when the run finishes.
+    /// EF Core migrations run once here too, against the real <c>Database</c>
+    /// DbContext, so a broken migration fails the whole run immediately.
+    /// </summary>
+    public sealed class InfrastructureTestFixture : IAsyncLifetime
     {
-        await Task.WhenAll(postgres.StartAsync(), seaweedFs.StartAsync());
+        public const string S3AccessKey = "musify-test";
+        public const string S3SecretKey = "musify-test-secret";
+        public const string S3Bucket = "musify-test-bucket";
 
-        await using var database = new Database(new DatabaseConfiguration { ConnectionString = ConnectionString });
-        await database.Database.MigrateAsync();
-
-        // SeaweedFS does not auto-create buckets (see deploy/compose.yml's seaweedfs-init).
-        using var s3 = CreateS3Client();
-        await s3.PutBucketAsync(S3Bucket);
-    }
-
-    public async ValueTask DisposeAsync()
-    {
-        await postgres.DisposeAsync();
-        await seaweedFs.DisposeAsync();
-    }
-
-    /// <summary>A fresh, DI-wired <see cref="Database"/>, so <c>AuditableEntityInterceptor</c>
-    /// (attached in <c>AddDatabase</c>'s DI registration, not in the class itself) is active —
-    /// same wiring the real app uses, not a bare <c>new Database(...)</c>.</summary>
-    public Database CreateDatabase()
-    {
-        var configuration = new ConfigurationBuilder()
-            .AddInMemoryCollection([new("Database:ConnectionString", ConnectionString)])
+        private readonly PostgreSqlContainer postgres = new PostgreSqlBuilder("postgres:17-alpine")
+            .WithDatabase("musify_test")
+            .WithUsername("postgres")
+            .WithPassword("postgres")
             .Build();
 
-        var services = new ServiceCollection();
-        services.AddDatabase(configuration);
-        return services.BuildServiceProvider().GetRequiredService<Database>();
-    }
+        private readonly IContainer seaweedFs = new ContainerBuilder("chrislusf/seaweedfs:latest")
+            .WithEntrypoint("/bin/sh", "-c")
+            .WithCommand(BuildSeaweedFsStartupScript())
+            .WithPortBinding(9333, assignRandomHostPort: true)
+            .WithPortBinding(8333, assignRandomHostPort: true)
+            .WithWaitStrategy(Wait.ForUnixContainer()
+                .UntilHttpRequestIsSucceeded(request => request.ForPort(9333).ForPath("/cluster/healthz")))
+            .Build();
 
-    /// <summary>An <see cref="IAmazonS3"/> client configured exactly like
-    /// <c>ServicesDependencyInjection.AddStorageService</c>, pointed at the SeaweedFS container.</summary>
-    public IAmazonS3 CreateS3Client() =>
-        new AmazonS3Client(S3AccessKey, S3SecretKey, new AmazonS3Config
-        {
-            ServiceURL = S3ServiceUrl,
-            ForcePathStyle = true,
-            UseHttp = true,
-        });
+        public string ConnectionString => postgres.GetConnectionString();
 
-    private static string BuildSeaweedFsStartupScript()
-    {
-        var identity = JsonSerializer.Serialize(new
+        public string S3ServiceUrl => $"http://{seaweedFs.Hostname}:{seaweedFs.GetMappedPublicPort(8333)}";
+
+        public async ValueTask InitializeAsync()
         {
-            identities = new[]
+            await Task.WhenAll(postgres.StartAsync(), seaweedFs.StartAsync());
+
+            await using var database = new Database(new DatabaseConfiguration { ConnectionString = ConnectionString });
+            await database.Database.MigrateAsync();
+
+            // SeaweedFS does not auto-create buckets (see deploy/compose.yml's seaweedfs-init).
+            using var s3 = CreateS3Client();
+            await s3.PutBucketAsync(S3Bucket);
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await postgres.DisposeAsync();
+            await seaweedFs.DisposeAsync();
+        }
+
+        /// <summary>A fresh, DI-wired <see cref="Database"/>, so <c>AuditableEntityInterceptor</c>
+        /// (attached in <c>AddDatabase</c>'s DI registration, not in the class itself) is active —
+        /// same wiring the real app uses, not a bare <c>new Database(...)</c>.</summary>
+        public Database CreateDatabase()
+        {
+            var configuration = new ConfigurationBuilder()
+                .AddInMemoryCollection([new("Database:ConnectionString", ConnectionString)])
+                .Build();
+
+            var services = new ServiceCollection();
+            services.AddDatabase(configuration);
+            return services.BuildServiceProvider().GetRequiredService<Database>();
+        }
+
+        /// <summary>An <see cref="IAmazonS3"/> client configured exactly like
+        /// <c>ServicesDependencyInjection.AddStorageService</c>, pointed at the SeaweedFS container.</summary>
+        public IAmazonS3 CreateS3Client() =>
+            new AmazonS3Client(S3AccessKey, S3SecretKey, new AmazonS3Config
             {
-                new
-                {
-                    name = "musify-test",
-                    credentials = new[] { new { accessKey = S3AccessKey, secretKey = S3SecretKey } },
-                    actions = new[] { "Admin", "Read", "Write" }
-                }
-            }
-        });
+                ServiceURL = S3ServiceUrl,
+                ForcePathStyle = true,
+                UseHttp = true,
+            });
 
-        return $"""
-            cat > /tmp/s3.conf <<'JSON'
-            {identity}
-            JSON
-            exec weed server -ip.bind=0.0.0.0 -dir=/data -master.volumeSizeLimitMB=1024 -volume.max=0 -filer -s3 -s3.config=/tmp/s3.conf
-            """;
+        private static string BuildSeaweedFsStartupScript()
+        {
+            var identity = JsonSerializer.Serialize(new
+            {
+                identities = new[]
+                {
+                    new
+                    {
+                        name = "musify-test",
+                        credentials = new[] { new { accessKey = S3AccessKey, secretKey = S3SecretKey } },
+                        actions = new[] { "Admin", "Read", "Write" }
+                    }
+                }
+            });
+
+            return $"""
+                cat > /tmp/s3.conf <<'JSON'
+                {identity}
+                JSON
+                exec weed server -ip.bind=0.0.0.0 -dir=/data -master.volumeSizeLimitMB=1024 -volume.max=0 -filer -s3 -s3.config=/tmp/s3.conf
+                """;
+        }
+    }
+
+    [CollectionDefinition(Name)]
+    public sealed class InfrastructureCollection : ICollectionFixture<InfrastructureTestFixture>
+    {
+        public const string Name = "Infrastructure";
     }
 }
-
-[CollectionDefinition(Name)]
-public sealed class InfrastructureCollection : ICollectionFixture<InfrastructureTestFixture>
-{
-    public const string Name = "Infrastructure";
-}
diff --git a/backend/Tests/Musify.StreamingGateway.Tests/Authentication/TicketValidatorTests.cs b/backend/Tests/Musify.StreamingGateway.Tests/Authentication/TicketValidatorTests.cs
index 1f95b55..d907ed4 100644
--- a/backend/Tests/Musify.StreamingGateway.Tests/Authentication/TicketValidatorTests.cs
+++ b/backend/Tests/Musify.StreamingGateway.Tests/Authentication/TicketValidatorTests.cs
@@ -6,141 +6,142 @@ using Musify.StreamingGateway.Authentication;
 using Musify.StreamingGateway.Configuration;
 using Xunit;
 
-namespace Musify.StreamingGateway.Tests.Authentication;
-
-public sealed class TicketValidatorTests : IDisposable
+namespace Musify.StreamingGateway.Tests.Authentication
 {
-    private const string Issuer = "musify-webapi";
-    private const string Audience = "media-gateway";
-
-    private readonly string publicKeyPath = Path.GetTempFileName();
-    private readonly RSA rsa = RSA.Create(2048);
-    private readonly JsonWebTokenHandler tokenHandler = new();
-
-    public TicketValidatorTests() => File.WriteAllText(publicKeyPath, rsa.ExportSubjectPublicKeyInfoPem());
-
-    public void Dispose()
+    public sealed class TicketValidatorTests : IDisposable
     {
-        rsa.Dispose();
-        File.Delete(publicKeyPath);
-    }
+        private const string Issuer = "musify-webapi";
+        private const string Audience = "media-gateway";
 
-    private TicketValidator CreateValidator() => new(Options.Create(new StreamTicketValidationOptions
-    {
-        PublicKeyPath = publicKeyPath,
-        Audience = Audience,
-        Issuer = Issuer
-    }));
+        private readonly string publicKeyPath = Path.GetTempFileName();
+        private readonly RSA rsa = RSA.Create(2048);
+        private readonly JsonWebTokenHandler tokenHandler = new();
 
-    private string IssueToken(string prefix = "Tracks/ProcessedAudios/abc/", string issuer = Issuer, string audience = Audience,
-        DateTime? expires = null, DateTime? notBefore = null)
-    {
-        var descriptor = new SecurityTokenDescriptor
+        public TicketValidatorTests() => File.WriteAllText(publicKeyPath, rsa.ExportSubjectPublicKeyInfoPem());
+
+        public void Dispose()
         {
-            Issuer = issuer,
-            Audience = audience,
-            NotBefore = notBefore ?? DateTime.UtcNow.AddMinutes(-1),
-            Expires = expires ?? DateTime.UtcNow.AddMinutes(5),
-            Claims = new Dictionary<string, object> { ["prefix"] = prefix },
-            SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
-        };
-        return tokenHandler.CreateToken(descriptor);
-    }
+            rsa.Dispose();
+            File.Delete(publicKeyPath);
+        }
 
-    [Fact]
-    public async Task ValidateTicketAsync_ValidToken_ReturnsThePrefixClaim()
-    {
-        var token = IssueToken(prefix: "Tracks/ProcessedAudios/xyz/");
-
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal("Tracks/ProcessedAudios/xyz/", prefix);
-    }
-
-    [Theory]
-    [InlineData(null)]
-    [InlineData("")]
-    [InlineData("   ")]
-    public async Task ValidateTicketAsync_BlankToken_ReturnsEmptyString(string? token)
-    {
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_MalformedToken_ReturnsEmptyString()
-    {
-        var prefix = await CreateValidator().ValidateTicketAsync("not-a-real-jwt");
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_ExpiredToken_ReturnsEmptyString()
-    {
-        var token = IssueToken(expires: DateTime.UtcNow.AddMinutes(-40), notBefore: DateTime.UtcNow.AddMinutes(-50));
-
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_WrongIssuer_ReturnsEmptyString()
-    {
-        var token = IssueToken(issuer: "someone-else");
-
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_WrongAudience_ReturnsEmptyString()
-    {
-        var token = IssueToken(audience: "someone-else");
-
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_SignedWithADifferentKey_ReturnsEmptyString()
-    {
-        using var otherKey = RSA.Create(2048);
-        var descriptor = new SecurityTokenDescriptor
+        private TicketValidator CreateValidator() => new(Options.Create(new StreamTicketValidationOptions
         {
-            Issuer = Issuer,
+            PublicKeyPath = publicKeyPath,
             Audience = Audience,
-            NotBefore = DateTime.UtcNow.AddMinutes(-1),
-            Expires = DateTime.UtcNow.AddMinutes(5),
-            Claims = new Dictionary<string, object> { ["prefix"] = "Tracks/ProcessedAudios/abc/" },
-            SigningCredentials = new SigningCredentials(new RsaSecurityKey(otherKey), SecurityAlgorithms.RsaSha256),
-        };
-        var token = tokenHandler.CreateToken(descriptor);
+            Issuer = Issuer
+        }));
 
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
-
-        Assert.Equal(string.Empty, prefix);
-    }
-
-    [Fact]
-    public async Task ValidateTicketAsync_MissingPrefixClaim_ReturnsEmptyString()
-    {
-        var descriptor = new SecurityTokenDescriptor
+        private string IssueToken(string prefix = "Tracks/ProcessedAudios/abc/", string issuer = Issuer, string audience = Audience,
+            DateTime? expires = null, DateTime? notBefore = null)
         {
-            Issuer = Issuer,
-            Audience = Audience,
-            NotBefore = DateTime.UtcNow.AddMinutes(-1),
-            Expires = DateTime.UtcNow.AddMinutes(5),
-            SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
-        };
-        var token = tokenHandler.CreateToken(descriptor);
+            var descriptor = new SecurityTokenDescriptor
+            {
+                Issuer = issuer,
+                Audience = audience,
+                NotBefore = notBefore ?? DateTime.UtcNow.AddMinutes(-1),
+                Expires = expires ?? DateTime.UtcNow.AddMinutes(5),
+                Claims = new Dictionary<string, object> { ["prefix"] = prefix },
+                SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
+            };
+            return tokenHandler.CreateToken(descriptor);
+        }
 
-        var prefix = await CreateValidator().ValidateTicketAsync(token);
+        [Fact]
+        public async Task ValidateTicketAsync_ValidToken_ReturnsThePrefixClaim()
+        {
+            var token = IssueToken(prefix: "Tracks/ProcessedAudios/xyz/");
 
-        Assert.Equal(string.Empty, prefix);
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal("Tracks/ProcessedAudios/xyz/", prefix);
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("   ")]
+        public async Task ValidateTicketAsync_BlankToken_ReturnsEmptyString(string? token)
+        {
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_MalformedToken_ReturnsEmptyString()
+        {
+            var prefix = await CreateValidator().ValidateTicketAsync("not-a-real-jwt");
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_ExpiredToken_ReturnsEmptyString()
+        {
+            var token = IssueToken(expires: DateTime.UtcNow.AddMinutes(-40), notBefore: DateTime.UtcNow.AddMinutes(-50));
+
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_WrongIssuer_ReturnsEmptyString()
+        {
+            var token = IssueToken(issuer: "someone-else");
+
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_WrongAudience_ReturnsEmptyString()
+        {
+            var token = IssueToken(audience: "someone-else");
+
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_SignedWithADifferentKey_ReturnsEmptyString()
+        {
+            using var otherKey = RSA.Create(2048);
+            var descriptor = new SecurityTokenDescriptor
+            {
+                Issuer = Issuer,
+                Audience = Audience,
+                NotBefore = DateTime.UtcNow.AddMinutes(-1),
+                Expires = DateTime.UtcNow.AddMinutes(5),
+                Claims = new Dictionary<string, object> { ["prefix"] = "Tracks/ProcessedAudios/abc/" },
+                SigningCredentials = new SigningCredentials(new RsaSecurityKey(otherKey), SecurityAlgorithms.RsaSha256),
+            };
+            var token = tokenHandler.CreateToken(descriptor);
+
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
+
+        [Fact]
+        public async Task ValidateTicketAsync_MissingPrefixClaim_ReturnsEmptyString()
+        {
+            var descriptor = new SecurityTokenDescriptor
+            {
+                Issuer = Issuer,
+                Audience = Audience,
+                NotBefore = DateTime.UtcNow.AddMinutes(-1),
+                Expires = DateTime.UtcNow.AddMinutes(5),
+                SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
+            };
+            var token = tokenHandler.CreateToken(descriptor);
+
+            var prefix = await CreateValidator().ValidateTicketAsync(token);
+
+            Assert.Equal(string.Empty, prefix);
+        }
     }
 }
diff --git a/backend/Tests/Musify.StreamingGateway.Tests/Middleware/TicketValidationMiddlewareTests.cs b/backend/Tests/Musify.StreamingGateway.Tests/Middleware/TicketValidationMiddlewareTests.cs
index 8585975..00bebdc 100644
--- a/backend/Tests/Musify.StreamingGateway.Tests/Middleware/TicketValidationMiddlewareTests.cs
+++ b/backend/Tests/Musify.StreamingGateway.Tests/Middleware/TicketValidationMiddlewareTests.cs
@@ -9,145 +9,146 @@ using Musify.StreamingGateway.Configuration;
 using Musify.StreamingGateway.Middleware;
 using Xunit;
 
-namespace Musify.StreamingGateway.Tests.Middleware;
-
-public sealed class TicketValidationMiddlewareTests : IDisposable
+namespace Musify.StreamingGateway.Tests.Middleware
 {
-    private const string Prefix = "Tracks/ProcessedAudios/abc";
-
-    private readonly string publicKeyPath = Path.GetTempFileName();
-    private readonly RSA rsa = RSA.Create(2048);
-    private readonly StreamTicketValidationOptions options;
-
-    public TicketValidationMiddlewareTests()
+    public sealed class TicketValidationMiddlewareTests : IDisposable
     {
-        File.WriteAllText(publicKeyPath, rsa.ExportSubjectPublicKeyInfoPem());
-        options = new StreamTicketValidationOptions
+        private const string Prefix = "Tracks/ProcessedAudios/abc";
+
+        private readonly string publicKeyPath = Path.GetTempFileName();
+        private readonly RSA rsa = RSA.Create(2048);
+        private readonly StreamTicketValidationOptions options;
+
+        public TicketValidationMiddlewareTests()
         {
-            PublicKeyPath = publicKeyPath,
-            Audience = "media-gateway",
-            Issuer = "musify-webapi",
-        };
-    }
+            File.WriteAllText(publicKeyPath, rsa.ExportSubjectPublicKeyInfoPem());
+            options = new StreamTicketValidationOptions
+            {
+                PublicKeyPath = publicKeyPath,
+                Audience = "media-gateway",
+                Issuer = "musify-webapi",
+            };
+        }
 
-    public void Dispose()
-    {
-        rsa.Dispose();
-        File.Delete(publicKeyPath);
-    }
+        public void Dispose()
+        {
+            rsa.Dispose();
+            File.Delete(publicKeyPath);
+        }
 
-    private string IssueValidToken(string prefix = Prefix) => new JsonWebTokenHandler().CreateToken(new SecurityTokenDescriptor
-    {
-        Issuer = options.Issuer,
-        Audience = options.Audience,
-        NotBefore = DateTime.UtcNow.AddMinutes(-1),
-        Expires = DateTime.UtcNow.AddMinutes(5),
-        Claims = new Dictionary<string, object> { ["prefix"] = prefix },
-        SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
-    });
+        private string IssueValidToken(string prefix = Prefix) => new JsonWebTokenHandler().CreateToken(new SecurityTokenDescriptor
+        {
+            Issuer = options.Issuer,
+            Audience = options.Audience,
+            NotBefore = DateTime.UtcNow.AddMinutes(-1),
+            Expires = DateTime.UtcNow.AddMinutes(5),
+            Claims = new Dictionary<string, object> { ["prefix"] = prefix },
+            SigningCredentials = new SigningCredentials(new RsaSecurityKey(rsa), SecurityAlgorithms.RsaSha256),
+        });
 
-    private (TicketValidationMiddleware Middleware, Func<bool> WasNextCalled) CreateMiddleware()
-    {
-        var nextCalled = false;
-        RequestDelegate next = _ => { nextCalled = true; return Task.CompletedTask; };
-        var validator = new TicketValidator(Options.Create(options));
-        var middleware = new TicketValidationMiddleware(next, validator, Options.Create(options), NullLogger<TicketValidationMiddleware>.Instance);
-        return (middleware, () => nextCalled);
-    }
+        private (TicketValidationMiddleware Middleware, Func<bool> WasNextCalled) CreateMiddleware()
+        {
+            var nextCalled = false;
+            RequestDelegate next = _ => { nextCalled = true; return Task.CompletedTask; };
+            var validator = new TicketValidator(Options.Create(options));
+            var middleware = new TicketValidationMiddleware(next, validator, Options.Create(options), NullLogger<TicketValidationMiddleware>.Instance);
+            return (middleware, () => nextCalled);
+        }
 
-    [Fact]
-    public async Task InvokeAsync_PathOutsideMediaPrefix_PassesThroughWithoutValidatingATicket()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = "/health";
+        [Fact]
+        public async Task InvokeAsync_PathOutsideMediaPrefix_PassesThroughWithoutValidatingATicket()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = "/health";
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.True(wasNextCalled());
-        Assert.Equal(StatusCodes.Status200OK, context.Response.StatusCode);
-    }
+            Assert.True(wasNextCalled());
+            Assert.Equal(StatusCodes.Status200OK, context.Response.StatusCode);
+        }
 
-    [Fact]
-    public async Task InvokeAsync_NoTicket_ReturnsUnauthorized()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = $"/media/{Prefix}/audio.m4a";
+        [Fact]
+        public async Task InvokeAsync_NoTicket_ReturnsUnauthorized()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = $"/media/{Prefix}/audio.m4a";
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.False(wasNextCalled());
-        Assert.Equal(StatusCodes.Status401Unauthorized, context.Response.StatusCode);
-    }
+            Assert.False(wasNextCalled());
+            Assert.Equal(StatusCodes.Status401Unauthorized, context.Response.StatusCode);
+        }
 
-    [Fact]
-    public async Task InvokeAsync_ValidTicketAsQueryParameter_ForTheRequestedObject_PassesThroughAndStripsTheTicket()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = $"/media/{Prefix}/audio.m4a";
-        context.Request.QueryString = new QueryString($"?t={IssueValidToken()}&keep=1");
+        [Fact]
+        public async Task InvokeAsync_ValidTicketAsQueryParameter_ForTheRequestedObject_PassesThroughAndStripsTheTicket()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = $"/media/{Prefix}/audio.m4a";
+            context.Request.QueryString = new QueryString($"?t={IssueValidToken()}&keep=1");
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.True(wasNextCalled());
-        Assert.Equal("keep=1", context.Request.QueryString.Value?.TrimStart('?'));
-    }
+            Assert.True(wasNextCalled());
+            Assert.Equal("keep=1", context.Request.QueryString.Value?.TrimStart('?'));
+        }
 
-    [Fact]
-    public async Task InvokeAsync_ValidTicketAsHeader_PassesThrough()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = $"/media/{Prefix}/audio.m4a";
-        context.Request.Headers["X-Stream-Ticket"] = IssueValidToken();
+        [Fact]
+        public async Task InvokeAsync_ValidTicketAsHeader_PassesThrough()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = $"/media/{Prefix}/audio.m4a";
+            context.Request.Headers["X-Stream-Ticket"] = IssueValidToken();
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.True(wasNextCalled());
-    }
+            Assert.True(wasNextCalled());
+        }
 
-    [Fact]
-    public async Task InvokeAsync_ObjectKeyOutsideAuthorizedPrefix_ReturnsForbidden()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = "/media/Tracks/ProcessedAudios/someone-elses-track/audio.m4a";
-        context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
+        [Fact]
+        public async Task InvokeAsync_ObjectKeyOutsideAuthorizedPrefix_ReturnsForbidden()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = "/media/Tracks/ProcessedAudios/someone-elses-track/audio.m4a";
+            context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.False(wasNextCalled());
-        Assert.Equal(StatusCodes.Status403Forbidden, context.Response.StatusCode);
-    }
+            Assert.False(wasNextCalled());
+            Assert.Equal(StatusCodes.Status403Forbidden, context.Response.StatusCode);
+        }
 
-    [Theory]
-    [InlineData($"/media/{Prefix}/../../etc/passwd")]
-    [InlineData($"/media/{Prefix}/./audio.m4a")]
-    public async Task InvokeAsync_PathTraversalSegment_ReturnsBadRequest(string path)
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = path;
-        context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
+        [Theory]
+        [InlineData($"/media/{Prefix}/../../etc/passwd")]
+        [InlineData($"/media/{Prefix}/./audio.m4a")]
+        public async Task InvokeAsync_PathTraversalSegment_ReturnsBadRequest(string path)
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = path;
+            context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.False(wasNextCalled());
-        Assert.Equal(StatusCodes.Status400BadRequest, context.Response.StatusCode);
-    }
+            Assert.False(wasNextCalled());
+            Assert.Equal(StatusCodes.Status400BadRequest, context.Response.StatusCode);
+        }
 
-    [Fact]
-    public async Task InvokeAsync_TicketPrefixExactlyMatchesTheRequestedObject_PassesThrough()
-    {
-        var (middleware, wasNextCalled) = CreateMiddleware();
-        var context = new DefaultHttpContext();
-        context.Request.Path = $"/media/{Prefix}";
-        context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
+        [Fact]
+        public async Task InvokeAsync_TicketPrefixExactlyMatchesTheRequestedObject_PassesThrough()
+        {
+            var (middleware, wasNextCalled) = CreateMiddleware();
+            var context = new DefaultHttpContext();
+            context.Request.Path = $"/media/{Prefix}";
+            context.Request.QueryString = new QueryString($"?t={IssueValidToken()}");
 
-        await middleware.InvokeAsync(context);
+            await middleware.InvokeAsync(context);
 
-        Assert.True(wasNextCalled());
+            Assert.True(wasNextCalled());
+        }
     }
 }