Remove YouTube integration from backend and deployment config

Drops the YouTube-backed second catalog source entirely: the
Local/External split on Track/Album collapses into single concrete
entities, Artist/TrackArtist/ExternalTrack/ExternalAlbum and the
YouTube service/download pipeline (yt-dlp, MassTransit consumer,
routing slip) are deleted, and mixes now source discovery only from
local listening history. Includes the RemoveYouTubeIntegration EF
Core migration and matching Worker/deploy/compose cleanup (no more
yt-dlp/python/deno in the Worker image, no thumbnail-cache/YtDlp
config sections).

backend/Tests/Musify.Application.Tests/PlayLists/AddTrackToPlayListCommandHandlerTests.cs

@@ -16,7 +16,7 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id);
-            var track = TestEntities.LocalTrack(owner);
+            var track = TestEntities.Track(owner);
             await SeedAsync(owner, playList, track);
 
             var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);
@@ -31,8 +31,8 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id);
-            var existingTrack = TestEntities.LocalTrack(owner, "Existing");
-            var newTrack = TestEntities.LocalTrack(owner, "New");
+            var existingTrack = TestEntities.Track(owner, "Existing");
+            var newTrack = TestEntities.Track(owner, "New");
             await SeedAsync(
                 owner, playList, existingTrack, newTrack,
                 new PlayListHasTrack { PlayListId = playList.Id, TrackId = existingTrack.Id, Position = 0 });
@@ -82,7 +82,7 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id);
-            var track = TestEntities.LocalTrack(owner);
+            var track = TestEntities.Track(owner);
             await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
             var result = await CreateHandler().Handle(new AddTrackToPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);

backend/Tests/Musify.Application.Tests/PlayLists/AddYouTubeTrackToPlayListCommandHandlerTests.cs

@@ -1,105 +0,0 @@
-using ErrorOr;
-using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
-using Musify.Application.PlayLists;
-using Musify.Application.Services;
-using Musify.Application.Tests.TestSupport;
-using Musify.Domain.Entities;
-using NSubstitute;
-using Xunit;
-
-namespace Musify.Application.Tests.PlayLists
-{
-    public sealed class AddYouTubeTrackToPlayListCommandHandlerTests : HandlerTestBase
-    {
-        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-        private readonly IYouTubeMusicService youTubeMusicService = Substitute.For<IYouTubeMusicService>();
-
-        private AddYouTubeTrackToPlayListCommandHandler CreateHandler()
-        {
-            var provisioner = new YouTubeTrackProvisioner(
-                Database, youTubeMusicService, TestConfigurations.Track(), NoOpLogger<YouTubeTrackProvisioner>());
-
-            return new AddYouTubeTrackToPlayListCommandHandler(
-                Database,
-                eventBus,
-                youTubeMusicService,
-                provisioner,
-                TestConfigurations.Storage(),
-                TestConfigurations.Track(),
-                NoOpLogger<AddYouTubeTrackToPlayListCommandHandler>());
-        }
-
-        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")]);
-
-        [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);
-
-            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
-
-            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>());
-        }
-
-        [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 owner = TestEntities.User();
-            var playList = TestEntities.PlayList(owner.Id);
-            await SeedAsync(owner, playList);
-
-            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "new-video"), 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>());
-        }
-
-        [Fact]
-        public async Task Handle_PlayListMissing_ReturnsNotFound()
-        {
-            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(1, Guid.NewGuid(), "abc123"), TestContext.Current.CancellationToken);
-
-            Assert.Equal(ErrorType.NotFound, 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 AddYouTubeTrackToPlayListCommand(stranger.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
-
-            Assert.Equal(ErrorType.Unauthorized, result.FirstError.Type);
-        }
-
-        [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 });
-
-            var result = await CreateHandler().Handle(new AddYouTubeTrackToPlayListCommand(owner.Id, playList.Id, "abc123"), TestContext.Current.CancellationToken);
-
-            Assert.Equal(ErrorType.Conflict, result.FirstError.Type);
-        }
-    }
-}

backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListByIdQueryHandlerTests.cs

@@ -15,7 +15,7 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id, visibility: Musify.Domain.ValueObjects.PlaylistVisibility.Public);
-            var track = TestEntities.LocalTrack(owner);
+            var track = TestEntities.Track(owner);
             await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
             var result = await CreateHandler().Handle(new GetPlayListByIdQuery(playList.Id), TestContext.Current.CancellationToken);

backend/Tests/Musify.Application.Tests/PlayLists/GetPlayListTracksQueryHandlerTests.cs

@@ -15,8 +15,8 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id);
-            var second = TestEntities.LocalTrack(owner, "Second");
-            var first = TestEntities.LocalTrack(owner, "First");
+            var second = TestEntities.Track(owner, "Second");
+            var first = TestEntities.Track(owner, "First");
             await SeedAsync(
                 owner, playList, second, first,
                 new PlayListHasTrack { PlayListId = playList.Id, TrackId = second.Id, Position = 1 },

backend/Tests/Musify.Application.Tests/PlayLists/RemoveTrackFromPlayListCommandHandlerTests.cs

@@ -15,7 +15,7 @@ namespace Musify.Application.Tests.PlayLists
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id);
-            var track = TestEntities.LocalTrack(owner);
+            var track = TestEntities.Track(owner);
             await SeedAsync(owner, playList, track, new PlayListHasTrack { PlayListId = playList.Id, TrackId = track.Id, Position = 0 });
 
             var result = await CreateHandler().Handle(new RemoveTrackFromPlayListCommand(owner.Id, playList.Id, track.Id), TestContext.Current.CancellationToken);