Merge remote-tracking branch 'origin/main' into feat/multi-rerun-collections-api

# Conflicts:
#	docs/blazor-route-parity.md
#	docs/endpoint-index.md

.gitea/workflows/docker-build.yml

@@ -50,6 +50,37 @@ jobs:
       - name: Restore
         run: dotnet restore
 
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22.x'
+          cache: npm
+          cache-dependency-path: web/package-lock.json
+
+      - name: Install SPA dependencies
+        working-directory: web
+        run: npm ci
+
+      - name: Check generated SPA API client
+        working-directory: web
+        run: npm run check:api
+
+      - name: Lint SPA
+        working-directory: web
+        run: npm run lint
+
+      - name: Typecheck SPA
+        working-directory: web
+        run: npm run typecheck
+
+      - name: Test SPA
+        working-directory: web
+        run: npm test -- --run
+
+      - name: Build SPA
+        working-directory: web
+        run: npm run build
+
       - name: Strip Scanner project ref (matches Docker build)
         run: sed -i '/Scanner/d' ErsatzTV/ErsatzTV.csproj
 
@@ -243,8 +274,8 @@ jobs:
             done
             echo "  FAIL $path (no 2xx containing '$needle' within timeout)"; return 1
           }
-          if check "/iptv/channels.m3u" "#EXTM3U" && check "/iptv/xmltv.xml" "<tv"; then
-            echo "Smoke + IPTV E2E passed: channels.m3u + xmltv.xml serve a valid playlist + guide"
+          if check "/iptv/channels.m3u" "#EXTM3U" && check "/iptv/xmltv.xml" "<tv" && check "/app/" "ChicoryTV"; then
+            echo "Smoke + IPTV E2E passed: channels.m3u + xmltv.xml serve a valid playlist + guide; /app/ serves the ChicoryTV SPA"
           else
             echo "===== container logs (tail) ====="; docker logs "$NAME" 2>&1 | tail -n 40 || true
             exit 1

.gitignore

@@ -3,9 +3,13 @@
 project.lock.json
 .DS_Store
 *.pyc
+.worktrees/
 
 # Claude Code
 .mcp/
+.mcp.json
+.agents/
+plugins/
 nupkg/
 
 # Visual Studio Code
@@ -48,3 +52,6 @@ scripts/download-test-content.sh
 docker-compose.override.yml
 
 ErsatzTV/wwwroot/v2/
+ErsatzTV/wwwroot/app/
+web/dist/
+web/node_modules/

.mcp.json

@@ -1,56 +0,0 @@
-{
-  "mcpServers": {
-    "docker-mcp": {
-      "command": "uvx",
-      "args": [
-        "mcp-server-docker"
-      ],
-      "env": {
-        "DOCKER_HOST": "ssh://timothy@192.168.1.99"
-      }
-    },
-    "ssh-mcp": {
-      "command": "npx",
-      "args": [
-        "-y",
-        "ssh-mcp",
-        "--",
-        "--host=192.168.1.99",
-        "--user=timothy"
-      ],
-      "env": {}
-    },
-    "gitea": {
-      "command": "gitea-mcp-server",
-      "args": [
-        "-t", "stdio",
-        "-host", "http://192.168.1.95:3000",
-        "-token", "8341af0733ab9ce084ea7adf38b76aa9ebc3bd67"
-      ],
-      "env": {}
-    },
-    "csharp-lsp": {
-      "command": "/usr/local/share/dotnet/dotnet",
-      "args": [
-        "run",
-        "--project", "/Users/timothy/ersatztv/.mcp/csharp-lsp-mcp/csharp-lsp-mcp/src/CSharpLspMcp",
-        "-c", "Release"
-      ],
-      "env": {
-        "PATH": "/usr/local/share/dotnet:/Users/timothy/.dotnet/tools:/usr/bin:/bin:/usr/sbin:/sbin"
-      }
-    },
-    "nuget": {
-      "command": "/usr/local/share/dotnet/dotnet",
-      "args": [
-        "dnx",
-        "NuGet.Mcp.Server",
-        "--source", "https://api.nuget.org/v3/index.json",
-        "--yes"
-      ],
-      "env": {
-        "DOTNET_ROOT": "/usr/local/share/dotnet"
-      }
-    }
-  }
-}

AGENTS.md

@@ -0,0 +1,15 @@
+# Codex Instructions
+
+## Verification Commands
+
+Run .NET restore, build, and test commands outside the sandbox by default in this repo. Sandboxed .NET commands can stall on NuGet/package/compiler cache access, while the same commands complete normally with approved unsandboxed execution.
+
+Preferred verification commands:
+
+```bash
+TZ=UTC dotnet restore ErsatzTV.sln -v minimal
+TZ=UTC dotnet build ErsatzTV.sln --no-restore -v minimal
+TZ=UTC dotnet test ErsatzTV.sln --no-build -v minimal
+```
+
+Use scoped escalated execution for these commands rather than first trying a sandboxed run.

CLAUDE.md

@@ -4,7 +4,8 @@ Custom IPTV channel server for Jellyfin. Forked from [ErsatzTV/ErsatzTV](https:/
 
 ## Architecture
 
-- **Language**: C# / .NET 10, Blazor Server UI (MudBlazor)
+- **Language**: C# / .NET 10
+- **UI**: ChicoryTV React SPA (`web/`, Vite, served at `/app`) over the REST API — the default UI; root `/` and migrated legacy routes 302 there (`ErsatzTV/LegacyUiRedirects.cs`). The legacy Blazor Server UI (MudBlazor) still serves the remaining un-migrated admin screens — playback troubleshooting, multi/rerun collections, and playlist editing depth; Blazor home = `/system/health`, reachable via the Settings → System "Classic UI" link. Media detail pages + image folder browser landed in the SPA via #141 (PR #183); its removal is #91 phase (b), gated on #145 (playback troubleshooting) and API gaps #151/#152/#153/#155 (scheduling parity #144/#162 DONE 2026-07-07: blocks/templates/decos/deco-templates/playout editors all in the SPA; #141/#158/#161/#180 also DONE)
 - **Pattern**: CQRS via MediatR — queries/commands in `ErsatzTV.Application/`
 - **Database**: EF Core (SQLite default, MySQL optional) — context in `ErsatzTV.Infrastructure/Data/TvContext.cs`
 - **Media**: FFmpeg via CliWrap, SkiaSharp for logo generation
@@ -14,7 +15,8 @@ Custom IPTV channel server for Jellyfin. Forked from [ErsatzTV/ErsatzTV](https:/
 
 | Project | Role |
 |---------|------|
-| `ErsatzTV/` | ASP.NET Core host, Blazor pages, API controllers, DI setup |
+| `ErsatzTV/` | ASP.NET Core host, API controllers, SPA static hosting, legacy Blazor pages, DI setup |
+| `web/` | ChicoryTV React SPA (Vite + TypeScript; builds into `ErsatzTV/wwwroot/app`) |
 | `ErsatzTV.Application/` | MediatR handlers (business logic) |
 | `ErsatzTV.Core/` | Domain entities, interfaces, no infrastructure deps |
 | `ErsatzTV.Infrastructure/` | EF Core repos, data access |
@@ -36,7 +38,7 @@ Custom IPTV channel server for Jellyfin. Forked from [ErsatzTV/ErsatzTV](https:/
 - **Docker host**: jazz (192.168.1.99), container `ersatztv`, port 8409
 - **Config volume**: `~/downloadswarm/ersatztv/` on jazz → `/config` in container
 - **SQLite DB**: `/config/ersatztv.sqlite3` (WAL mode, root-owned)
-- **Images** (our fork, built by `.gitea/workflows/docker-build.yml` → `192.168.1.95:3000/timothy/ersatztv`): push to `main` → `:latest` + `:<sha>` (test image); push `v*` tag → `:prod` + `:<version>` + `:<sha>`. Prod container still runs upstream `ghcr.io/ersatztv/ersatztv:latest` pending cutover (server-management#481). Pipeline details: `docs/ci-cd.md`.
+- **Images** (our fork, built by `.gitea/workflows/docker-build.yml` → `192.168.1.95:3000/timothy/ersatztv`): push to `main` → `:latest` + `:<sha>` (test image); push `v*` tag → `:prod` + `:<version>` + `:<sha>`. Prod deploys via **Komodo GitOps**: the `media-servers` compose in `timothy/server-management` (`docker/bumblebee/stacks/media-servers/compose.yaml`) pins the version tag (currently `26.5.0`, deployed 2026-07-07); releasing = tag here, wait for the image build, bump that pin and push (the Komodo pre-deploy hook backs up before recreating). Test container tracks `:latest`. Pipeline details: `docs/ci-cd.md`.
 
 ## Development
 
@@ -54,9 +56,10 @@ docker build -f docker/Dockerfile -t ersatztv:dev .
 ## Conventions
 
 - **Read [`docs/contributing.md`](docs/contributing.md)** before non-trivial changes — it documents the established patterns (layering, CQRS handlers, LanguageExt, Blazor/MudBlazor, EF Core + dual-provider migrations, the FFmpeg pipeline, analyzers, testing) and the **deviation policy**: match the established style; diverge only with a concrete, stated reason.
+- **Convention docs replace re-recon**: before API/SPA/E2E/parity work, read `docs/README.md` (index) → `docs/api-conventions.md`, `docs/spa-conventions.md`, `docs/e2e-local.md`, `docs/domain-model.md`, `docs/blazor-route-parity.md`, `docs/decisions.md`. Any PR that changes a convention, migrates a route, or reverses a decision MUST update the relevant doc in the same PR.
 - Follow existing MediatR CQRS pattern for new features
 - Domain logic in `ErsatzTV.Core`, infrastructure in `ErsatzTV.Infrastructure`
-- Keep Blazor pages thin — delegate to MediatR handlers
+- Keep UI thin: the SPA talks to `/api/*` only; legacy Blazor pages delegate to MediatR handlers. New screens go in the SPA (`web/`), never in Blazor
 - Test with **NUnit** + Shouldly + NSubstitute (the existing `*.Tests` projects); xUnit is **not** used here
 - **Dependencies use Central Package Management**: versions live in the repo-root `Directory.Packages.props`; csproj reference packages by name only. Add/upgrade by editing the central `<PackageVersion>` — never put `Version=` back on a `<PackageReference>` (trips `NU1008`). See `docs/ci-cd.md` → Dependency management.
 - **DB migrations target BOTH providers**: a `TvContext` model change needs a migration in `ErsatzTV.Infrastructure.Sqlite` **and** `ErsatzTV.Infrastructure.MySql` — run `scripts/add-migration.sh <Name>` (does both). CI's `migrations` job enforces model-drift + apply-to-fresh-DB per provider. See `docs/ci-cd.md` → Migration integrity.

Directory.Packages.props

@@ -6,18 +6,18 @@
   <ItemGroup>
     <PackageVersion Include="AsyncFixer" Version="2.1.0" />
     <PackageVersion Include="Blazored.FluentValidation" Version="2.2.0" />
-    <PackageVersion Include="BlazorSortable" Version="5.2.1" />
+    <PackageVersion Include="BlazorSortable" Version="6.0.2" />
     <PackageVersion Include="Blurhash.SkiaSharp" Version="2.0.0" />
     <PackageVersion Include="Chronic.Core" Version="0.4.0" />
-    <PackageVersion Include="CliWrap" Version="3.10.0" />
+    <PackageVersion Include="CliWrap" Version="3.10.2" />
     <PackageVersion Include="coverlet.collector" Version="6.0.4" />
-    <PackageVersion Include="Dapper" Version="2.1.66" />
+    <PackageVersion Include="Dapper" Version="2.1.79" />
     <PackageVersion Include="Destructurama.Attributed" Version="5.2.0" />
     <PackageVersion Include="EFCore.BulkExtensions" Version="[9.0.2,10)" />
     <PackageVersion Include="EFCore.BulkExtensions.MySql" Version="[9.0.2,10)" />
     <PackageVersion Include="EFCore.BulkExtensions.Sqlite" Version="[9.0.2,10)" />
     <PackageVersion Include="Elastic.Clients.Elasticsearch" Version="9.3.0" />
-    <PackageVersion Include="EntityFrameworkProfiler.Appender" Version="6.0.6049" />
+    <PackageVersion Include="EntityFrameworkProfiler.Appender" Version="6.0.6053" />
     <PackageVersion Include="FluentValidation" Version="12.1.1" />
     <PackageVersion Include="FluentValidation.AspNetCore" Version="11.3.1" />
     <PackageVersion Include="Flurl" Version="4.0.0" />
@@ -79,7 +79,7 @@
     <PackageVersion Include="RichTextKit.Stbear" Version="0.4.167.3" />
     <PackageVersion Include="Roslynator.Analyzers" Version="4.15.0" />
     <PackageVersion Include="Scalar.AspNetCore" Version="2.12.32" />
-    <PackageVersion Include="Scriban.Signed" Version="6.5.2" />
+    <PackageVersion Include="Scriban.Signed" Version="7.2.5" />
     <PackageVersion Include="Serilog" Version="4.3.0" />
     <PackageVersion Include="Serilog.AspNetCore" Version="10.0.0" />
     <PackageVersion Include="Serilog.Extensions.Hosting" Version="10.0.0" />

ErsatzTV.Application/Artworks/Commands/UploadArtwork.cs

@@ -0,0 +1,13 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Artwork;
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Application.Artworks;
+
+/// <summary>
+///     Validates and stores an uploaded image as channel logo or watermark artwork,
+///     landing it in the same on-disk cache the Blazor UI uses (via <c>IImageCache</c>),
+///     so the returned path is equivalent to a Blazor-uploaded image.
+/// </summary>
+public record UploadArtwork(Stream Stream, string ContentType, ArtworkKind ArtworkKind)
+    : IRequest<Either<BaseError, ArtworkUploadResponseModel>>;

ErsatzTV.Application/Artworks/Commands/UploadArtworkHandler.cs

@@ -0,0 +1,53 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Artwork;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Images;
+
+namespace ErsatzTV.Application.Artworks;
+
+public class UploadArtworkHandler : IRequestHandler<UploadArtwork, Either<BaseError, ArtworkUploadResponseModel>>
+{
+    // png/jpeg/gif/webp are all decoded by SkiaSharp and read by FFmpeg, matching the
+    // formats the Blazor logo/watermark upload already accepts. Format expansion is ersatztv#66.
+    private static readonly System.Collections.Generic.HashSet<string> AcceptedContentTypes = new(StringComparer.OrdinalIgnoreCase)
+    {
+        "image/png",
+        "image/jpeg",
+        "image/gif",
+        "image/webp"
+    };
+
+    private readonly IImageCache _imageCache;
+
+    public UploadArtworkHandler(IImageCache imageCache) => _imageCache = imageCache;
+
+    public async Task<Either<BaseError, ArtworkUploadResponseModel>> Handle(
+        UploadArtwork request,
+        CancellationToken cancellationToken)
+    {
+        string contentType = (request.ContentType ?? string.Empty).Trim();
+        if (!AcceptedContentTypes.Contains(contentType))
+        {
+            return BaseError.New(
+                $"Unsupported image content type '{contentType}'; supported types are: {string.Join(", ", AcceptedContentTypes)}");
+        }
+
+        Either<BaseError, string> maybeFileName = await _imageCache.SaveArtworkToCache(
+            request.Stream,
+            request.ArtworkKind);
+
+        return maybeFileName.Map(fileName => new ArtworkUploadResponseModel(
+            BuildPath(request.ArtworkKind, fileName),
+            contentType));
+    }
+
+    // Mirror the on-disk conventions the Blazor editors use so the returned path is a drop-in
+    // for ArtworkContentTypeModel.Path: channel logos are addressed as "iptv/logos/{file}"
+    // (see ChannelEditor.UploadLogo), watermarks by the bare cache file name (see WatermarkEditor).
+    private static string BuildPath(ArtworkKind artworkKind, string fileName) =>
+        artworkKind switch
+        {
+            ArtworkKind.Logo => $"iptv/logos/{fileName}",
+            _ => fileName
+        };
+}

ErsatzTV.Application/ChannelTemplates/ChannelTemplateDefault.cs

@@ -0,0 +1,24 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+internal static class ChannelTemplateDefault
+{
+    public static async Task<int?> GetDefaultTemplateId(
+        IConfigElementRepository configElementRepository,
+        CancellationToken cancellationToken)
+    {
+        Option<int> maybeDefault =
+            await configElementRepository.GetValue<int>(
+                ConfigElementKey.ChannelTemplatesDefaultTemplateId,
+                cancellationToken);
+        int? result = null;
+        foreach (int id in maybeDefault)
+        {
+            result = id;
+        }
+
+        return result;
+    }
+}

ErsatzTV.Application/ChannelTemplates/ChannelTemplateMapper.cs

@@ -0,0 +1,38 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public static class ChannelTemplateMapper
+{
+    public static ChannelTemplateResponseModel ProjectToResponseModel(ChannelTemplate template, int? defaultTemplateId) =>
+        new(
+            template.Id,
+            template.Name,
+            template.Description,
+            template.IsSystem,
+            defaultTemplateId == template.Id,
+            template.FFmpegProfileId,
+            template.WatermarkId,
+            template.FallbackFillerId,
+            template.PreRollFillerId,
+            template.MidRollFillerId,
+            template.PostRollFillerId,
+            template.StreamSelectorMode,
+            template.StreamSelector,
+            template.PreferredAudioLanguageCode,
+            template.PreferredAudioTitle,
+            template.PlayoutSource,
+            template.PlayoutMode,
+            template.StreamingMode,
+            template.PreferredSubtitleLanguageCode,
+            template.SubtitleMode,
+            template.MusicVideoCreditsMode,
+            template.MusicVideoCreditsTemplate,
+            template.SongVideoMode,
+            template.TranscodeMode,
+            template.IdleBehavior,
+            template.ShuffleScheduleItems,
+            template.RandomStartPoint,
+            template.FixedStartTimeBehavior);
+}

ErsatzTV.Application/ChannelTemplates/Commands/ChannelTemplateCommandBase.cs

@@ -0,0 +1,155 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public abstract record ChannelTemplateCommandBase(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+{
+    internal static async Task<Option<BaseError>> ValidateCommon(
+        TvContext dbContext,
+        ChannelTemplateCommandBase request,
+        int? existingTemplateId,
+        CancellationToken cancellationToken)
+    {
+        string name = NormalizeName(request.Name);
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            return BaseError.New("Name is required.");
+        }
+
+        if (name.Length > 50)
+        {
+            return BaseError.New("Name must be 50 characters or less.");
+        }
+
+        if (request.Description?.Length > 500)
+        {
+            return BaseError.New("Description must be 500 characters or less.");
+        }
+
+        bool duplicateName = await dbContext.ChannelTemplates
+            .AnyAsync(t => t.Id != existingTemplateId && t.Name == name, cancellationToken);
+        if (duplicateName)
+        {
+            return BaseError.New("Channel template name must be unique.");
+        }
+
+        bool ffmpegProfileExists = await dbContext.FFmpegProfiles
+            .AnyAsync(p => p.Id == request.FFmpegProfileId, cancellationToken);
+        if (!ffmpegProfileExists)
+        {
+            return new NotFoundError($"FFmpegProfile {request.FFmpegProfileId} does not exist.");
+        }
+
+        foreach (int watermarkId in Optional(request.WatermarkId))
+        {
+            bool watermarkExists = await dbContext.ChannelWatermarks
+                .AnyAsync(w => w.Id == watermarkId, cancellationToken);
+            if (!watermarkExists)
+            {
+                return new NotFoundError($"Watermark {watermarkId} does not exist.");
+            }
+        }
+
+        Option<BaseError> maybeFillerError =
+            await FillerMustExist(dbContext, request.FallbackFillerId, FillerKind.Fallback, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        maybeFillerError = await FillerMustExist(dbContext, request.PreRollFillerId, FillerKind.PreRoll, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        maybeFillerError = await FillerMustExist(dbContext, request.MidRollFillerId, FillerKind.MidRoll, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        return await FillerMustExist(dbContext, request.PostRollFillerId, FillerKind.PostRoll, cancellationToken);
+    }
+
+    internal void ApplyTo(ChannelTemplate template)
+    {
+        template.Name = NormalizeName(Name);
+        template.Description = Description ?? string.Empty;
+        template.FFmpegProfileId = FFmpegProfileId;
+        template.WatermarkId = WatermarkId;
+        template.FallbackFillerId = FallbackFillerId;
+        template.PreRollFillerId = PreRollFillerId;
+        template.MidRollFillerId = MidRollFillerId;
+        template.PostRollFillerId = PostRollFillerId;
+        template.StreamSelectorMode = StreamSelectorMode;
+        template.StreamSelector = StreamSelector ?? string.Empty;
+        template.PreferredAudioLanguageCode = PreferredAudioLanguageCode ?? string.Empty;
+        template.PreferredAudioTitle = PreferredAudioTitle ?? string.Empty;
+        template.PlayoutSource = PlayoutSource;
+        template.PlayoutMode = PlayoutMode;
+        template.StreamingMode = StreamingMode;
+        template.PreferredSubtitleLanguageCode = PreferredSubtitleLanguageCode ?? string.Empty;
+        template.SubtitleMode = SubtitleMode;
+        template.MusicVideoCreditsMode = MusicVideoCreditsMode;
+        template.MusicVideoCreditsTemplate = MusicVideoCreditsTemplate ?? string.Empty;
+        template.SongVideoMode = SongVideoMode;
+        template.TranscodeMode = TranscodeMode;
+        template.IdleBehavior = IdleBehavior;
+        template.ShuffleScheduleItems = ShuffleScheduleItems;
+        template.RandomStartPoint = RandomStartPoint;
+        template.FixedStartTimeBehavior = FixedStartTimeBehavior;
+    }
+
+    internal static string NormalizeName(string name) => (name ?? string.Empty).Trim();
+
+    private static async Task<Option<BaseError>> FillerMustExist(
+        TvContext dbContext,
+        int? fillerPresetId,
+        FillerKind fillerKind,
+        CancellationToken cancellationToken)
+    {
+        foreach (int id in Optional(fillerPresetId))
+        {
+            bool exists = await dbContext.FillerPresets
+                .AnyAsync(f => f.Id == id && f.FillerKind == fillerKind, cancellationToken);
+            if (!exists)
+            {
+                return new NotFoundError($"{fillerKind} filler {id} does not exist.");
+            }
+        }
+
+        return Option<BaseError>.None;
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/CreateChannelTemplate.cs

@@ -0,0 +1,60 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record CreateChannelTemplate(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+    : ChannelTemplateCommandBase(
+        Name,
+        Description,
+        FFmpegProfileId,
+        WatermarkId,
+        FallbackFillerId,
+        PreRollFillerId,
+        MidRollFillerId,
+        PostRollFillerId,
+        StreamSelectorMode,
+        StreamSelector,
+        PreferredAudioLanguageCode,
+        PreferredAudioTitle,
+        PlayoutSource,
+        PlayoutMode,
+        StreamingMode,
+        PreferredSubtitleLanguageCode,
+        SubtitleMode,
+        MusicVideoCreditsMode,
+        MusicVideoCreditsTemplate,
+        SongVideoMode,
+        TranscodeMode,
+        IdleBehavior,
+        ShuffleScheduleItems,
+        RandomStartPoint,
+        FixedStartTimeBehavior),
+        IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/CreateChannelTemplateHandler.cs

@@ -0,0 +1,36 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class CreateChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<CreateChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        CreateChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<BaseError> maybeError =
+            await ChannelTemplateCommandBase.ValidateCommon(dbContext, request, null, cancellationToken);
+        foreach (BaseError error in maybeError)
+        {
+            return error;
+        }
+
+        var template = new ChannelTemplate();
+        request.ApplyTo(template);
+        await dbContext.ChannelTemplates.AddAsync(template, cancellationToken);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        return ChannelTemplateMapper.ProjectToResponseModel(template, defaultTemplateId);
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/DeleteChannelTemplate.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record DeleteChannelTemplate(int ChannelTemplateId) : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/ChannelTemplates/Commands/DeleteChannelTemplateHandler.cs

@@ -0,0 +1,42 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class DeleteChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<DeleteChannelTemplate, Either<BaseError, Unit>>
+{
+    public async Task<Either<BaseError, Unit>> Handle(DeleteChannelTemplate request, CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            if (template.IsSystem)
+            {
+                return BaseError.New("System templates cannot be deleted.");
+            }
+
+            int? defaultTemplateId =
+                await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+            if (defaultTemplateId == template.Id)
+            {
+                return BaseError.New("Default channel template cannot be deleted.");
+            }
+
+            dbContext.ChannelTemplates.Remove(template);
+            await dbContext.SaveChangesAsync(cancellationToken);
+            return Unit.Default;
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/SetDefaultChannelTemplate.cs

@@ -0,0 +1,6 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record SetDefaultChannelTemplate(int ChannelTemplateId) : IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/SetDefaultChannelTemplateHandler.cs

@@ -0,0 +1,36 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class SetDefaultChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<SetDefaultChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        SetDefaultChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            await configElementRepository.Upsert(
+                ConfigElementKey.ChannelTemplatesDefaultTemplateId,
+                template.Id,
+                cancellationToken);
+            return ChannelTemplateMapper.ProjectToResponseModel(template, template.Id);
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/UpdateChannelTemplate.cs

@@ -0,0 +1,61 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record UpdateChannelTemplate(
+    int ChannelTemplateId,
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+    : ChannelTemplateCommandBase(
+        Name,
+        Description,
+        FFmpegProfileId,
+        WatermarkId,
+        FallbackFillerId,
+        PreRollFillerId,
+        MidRollFillerId,
+        PostRollFillerId,
+        StreamSelectorMode,
+        StreamSelector,
+        PreferredAudioLanguageCode,
+        PreferredAudioTitle,
+        PlayoutSource,
+        PlayoutMode,
+        StreamingMode,
+        PreferredSubtitleLanguageCode,
+        SubtitleMode,
+        MusicVideoCreditsMode,
+        MusicVideoCreditsTemplate,
+        SongVideoMode,
+        TranscodeMode,
+        IdleBehavior,
+        ShuffleScheduleItems,
+        RandomStartPoint,
+        FixedStartTimeBehavior),
+        IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/UpdateChannelTemplateHandler.cs

@@ -0,0 +1,51 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class UpdateChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<UpdateChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        UpdateChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            if (template.IsSystem)
+            {
+                return BaseError.New("System templates cannot be updated.");
+            }
+
+            Option<BaseError> maybeError =
+                await ChannelTemplateCommandBase.ValidateCommon(
+                    dbContext,
+                    request,
+                    request.ChannelTemplateId,
+                    cancellationToken);
+            foreach (BaseError error in maybeError)
+            {
+                return error;
+            }
+
+            request.ApplyTo(template);
+            await dbContext.SaveChangesAsync(cancellationToken);
+            int? defaultTemplateId =
+                await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+            return ChannelTemplateMapper.ProjectToResponseModel(template, defaultTemplateId);
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetAllChannelTemplates.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetAllChannelTemplates : IRequest<List<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetAllChannelTemplatesHandler.cs

@@ -0,0 +1,28 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetAllChannelTemplatesHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetAllChannelTemplates, List<ChannelTemplateResponseModel>>
+{
+    public async Task<List<ChannelTemplateResponseModel>> Handle(
+        GetAllChannelTemplates request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        return await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .OrderBy(t => t.IsSystem ? 0 : 1)
+            .ThenBy(t => t.Name)
+            .Select(t => ChannelTemplateMapper.ProjectToResponseModel(t, defaultTemplateId))
+            .ToListAsync(cancellationToken);
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetChannelTemplateById.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetChannelTemplateById(int ChannelTemplateId) : IRequest<Option<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetChannelTemplateByIdHandler.cs

@@ -0,0 +1,27 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetChannelTemplateByIdHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetChannelTemplateById, Option<ChannelTemplateResponseModel>>
+{
+    public async Task<Option<ChannelTemplateResponseModel>> Handle(
+        GetChannelTemplateById request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        return maybeTemplate.Map(t => ChannelTemplateMapper.ProjectToResponseModel(t, defaultTemplateId));
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetDefaultChannelTemplate.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetDefaultChannelTemplate : IRequest<Option<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetDefaultChannelTemplateHandler.cs

@@ -0,0 +1,40 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetDefaultChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetDefaultChannelTemplate, Option<ChannelTemplateResponseModel>>
+{
+    public async Task<Option<ChannelTemplateResponseModel>> Handle(
+        GetDefaultChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        foreach (int id in Optional(defaultTemplateId))
+        {
+            Option<ChannelTemplate> maybeConfigured = await dbContext.ChannelTemplates
+                .AsNoTracking()
+                .SelectOneAsync(t => t.Id, t => t.Id == id, cancellationToken);
+            foreach (ChannelTemplate template in maybeConfigured)
+            {
+                return ChannelTemplateMapper.ProjectToResponseModel(template, id);
+            }
+        }
+
+        ChannelTemplate fallback = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .Where(t => t.IsSystem)
+            .OrderBy(t => t.Name)
+            .FirstOrDefaultAsync(cancellationToken);
+        return Optional(fallback).Map(t => ChannelTemplateMapper.ProjectToResponseModel(t, t.Id));
+    }
+}

ErsatzTV.Application/Channels/ChannelGuideMetadata.cs

@@ -0,0 +1,71 @@
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Application.Channels;
+
+/// <summary>
+///     Shared programme-metadata projection for guide output. Both the XMLTV cache builder
+///     (<see cref="RefreshChannelDataHandler" />) and the JSON guide query
+///     (<see cref="GetChannelGuideDataHandler" />) resolve the display title/subtitle/category from a
+///     <see cref="PlayoutItem" /> here so the two representations stay consistent.
+/// </summary>
+public static class ChannelGuideMetadata
+{
+    public static string GetTitle(PlayoutItem playoutItem)
+    {
+        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
+        {
+            return playoutItem.CustomTitle;
+        }
+
+        return playoutItem.MediaItem switch
+        {
+            Movie m => m.MovieMetadata.HeadOrNone().Map(mm => mm.Title ?? string.Empty)
+                .IfNone("[unknown movie]"),
+            Episode e => e.Season.Show.ShowMetadata.HeadOrNone().Map(em => em.Title ?? string.Empty)
+                .IfNone("[unknown show]"),
+            MusicVideo mv => mv.Artist.ArtistMetadata.HeadOrNone().Map(am => am.Title ?? string.Empty)
+                .IfNone("[unknown artist]"),
+            OtherVideo ov => ov.OtherVideoMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
+                .IfNone("[unknown video]"),
+            RemoteStream rs => rs.RemoteStreamMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
+                .IfNone("[unknown remote stream]"),
+            _ => "[unknown]"
+        };
+    }
+
+    public static string GetSubtitle(PlayoutItem playoutItem)
+    {
+        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
+        {
+            return string.Empty;
+        }
+
+        return playoutItem.MediaItem switch
+        {
+            Episode e => e.EpisodeMetadata.HeadOrNone().Match(
+                em => em.Title ?? string.Empty,
+                () => string.Empty),
+            MusicVideo mv => mv.MusicVideoMetadata.HeadOrNone().Match(
+                mvm => mvm.Title ?? string.Empty,
+                () => string.Empty),
+            Song s => s.SongMetadata.HeadOrNone().Match(
+                mvm => mvm.Title ?? string.Empty,
+                () => string.Empty),
+            _ => string.Empty
+        };
+    }
+
+    /// <summary>
+    ///     The primary guide category, mirroring the fixed <c>&lt;category&gt;</c> the XMLTV templates
+    ///     emit per media kind (Movie / Series / Music). Media kinds without a fixed category return null.
+    /// </summary>
+    public static string GetCategory(PlayoutItem playoutItem) =>
+        playoutItem.MediaItem switch
+        {
+            Movie => "Movie",
+            Episode => "Series",
+            MusicVideo => "Music",
+            Song => "Music",
+            _ => null
+        };
+}

ErsatzTV.Application/Channels/ChannelGuideProjector.cs

@@ -0,0 +1,164 @@
+using ErsatzTV.Application.Configuration;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+
+namespace ErsatzTV.Application.Channels;
+
+/// <summary>
+///     A single guide programme resolved from one or more <see cref="PlayoutItem" />s: the
+///     <see cref="DisplayItem" /> whose metadata is shown, plus the coalesced <see cref="Start" />/
+///     <see cref="Stop" /> window and whether the originating item carried a custom title.
+/// </summary>
+public readonly record struct ChannelGuideEntry(
+    PlayoutItem DisplayItem,
+    DateTimeOffset Start,
+    DateTimeOffset Stop,
+    bool HasCustomTitle);
+
+/// <summary>
+///     Shared guide-group / filler-merge projection. This is the single source of truth for turning a
+///     channel's sorted <see cref="PlayoutItem" />s into guide programmes; both the XMLTV cache builder
+///     (<see cref="RefreshChannelDataHandler" />) and the JSON guide query
+///     (<see cref="GetChannelGuideDataHandler" />) consume it so the two representations cannot drift.
+///     The XMLTV path formats <see cref="ChannelGuideEntry.Start" />/<see cref="ChannelGuideEntry.Stop" />
+///     into the XMLTV timestamp strings; the JSON path returns them (and the display item's
+///     <see cref="FillerKind" />) directly and lets the UI decide how to render filler.
+/// </summary>
+public static class ChannelGuideProjector
+{
+    public static IEnumerable<ChannelGuideEntry> Project(
+        PlayoutScheduleKind scheduleKind,
+        IReadOnlyList<PlayoutItem> sorted,
+        XmltvTimeZone timeZone,
+        XmltvBlockBehavior blockBehavior) =>
+        scheduleKind switch
+        {
+            PlayoutScheduleKind.Block => ProjectBlock(sorted, timeZone, blockBehavior),
+            _ => ProjectFlood(sorted, timeZone)
+        };
+
+    // Classic / Sequential / Scripted / ExternalJson: skip leading non-preroll filler, then coalesce
+    // each guide group (following filler) into a single programme using the display item's GuideFinish
+    // override when present.
+    private static IEnumerable<ChannelGuideEntry> ProjectFlood(
+        IReadOnlyList<PlayoutItem> sorted,
+        XmltvTimeZone timeZone)
+    {
+        // skip all filler that isn't pre-roll
+        var i = 0;
+        while (i < sorted.Count && sorted[i].FillerKind != FillerKind.None &&
+               sorted[i].FillerKind != FillerKind.PreRoll)
+        {
+            i++;
+        }
+
+        while (i < sorted.Count)
+        {
+            PlayoutItem startItem = sorted[i];
+            int j = i;
+            while (sorted[j].FillerKind != FillerKind.None && j + 1 < sorted.Count)
+            {
+                j++;
+            }
+
+            PlayoutItem displayItem = sorted[j];
+            bool hasCustomTitle = !string.IsNullOrWhiteSpace(startItem.CustomTitle);
+
+            int finishIndex = j;
+            while (finishIndex + 1 < sorted.Count && (sorted[finishIndex + 1].GuideGroup == startItem.GuideGroup
+                                                      || sorted[finishIndex + 1].FillerKind is FillerKind.GuideMode
+                                                          or FillerKind.PostRoll or FillerKind.Tail
+                                                          or FillerKind.Fallback or FillerKind.DecoDefault))
+            {
+                finishIndex++;
+            }
+
+            PlayoutItem finishItem = sorted[finishIndex];
+            i = finishIndex;
+
+            DateTimeOffset startTime = timeZone switch
+            {
+                XmltvTimeZone.Utc => new DateTimeOffset(startItem.Start, TimeSpan.Zero),
+                _ => startItem.StartOffset
+            };
+
+            DateTimeOffset stopTime = (timeZone, displayItem.GuideFinishOffset.HasValue) switch
+            {
+                (XmltvTimeZone.Utc, true) => new DateTimeOffset(displayItem.GuideFinish!.Value, TimeSpan.Zero),
+                (XmltvTimeZone.Utc, false) => new DateTimeOffset(finishItem.Finish, TimeSpan.Zero),
+                (_, true) => displayItem.GuideFinishOffset!.Value,
+                (_, false) => finishItem.FinishOffset
+            };
+
+            yield return new ChannelGuideEntry(displayItem, startTime, stopTime, hasCustomTitle);
+
+            i++;
+        }
+    }
+
+    // Block: group by guide window, drop filler entirely, then either use the items' actual times or
+    // split the group window evenly across the non-filler items.
+    private static IEnumerable<ChannelGuideEntry> ProjectBlock(
+        IReadOnlyList<PlayoutItem> sorted,
+        XmltvTimeZone timeZone,
+        XmltvBlockBehavior blockBehavior)
+    {
+        var groups = sorted.GroupBy(s => new { s.GuideStart, s.GuideFinish, s.GuideGroup });
+        foreach (var group in groups)
+        {
+            var itemsToInclude = group.Filter(g => g.FillerKind is FillerKind.None).ToList();
+            if (itemsToInclude.Count == 0)
+            {
+                continue;
+            }
+
+            switch (blockBehavior)
+            {
+                case XmltvBlockBehavior.UseActualTimes:
+                    foreach (PlayoutItem item in itemsToInclude)
+                    {
+                        DateTimeOffset actualStart = timeZone switch
+                        {
+                            XmltvTimeZone.Utc => new DateTimeOffset(item.Start, TimeSpan.Zero),
+                            _ => new DateTimeOffset(item.Start, TimeSpan.Zero).ToLocalTime()
+                        };
+
+                        DateTimeOffset actualFinish = timeZone switch
+                        {
+                            XmltvTimeZone.Utc => new DateTimeOffset(item.Finish, TimeSpan.Zero),
+                            _ => new DateTimeOffset(item.Finish, TimeSpan.Zero).ToLocalTime()
+                        };
+
+                        yield return new ChannelGuideEntry(item, actualStart, actualFinish, false);
+                    }
+
+                    break;
+                case XmltvBlockBehavior.SplitTimeEvenly:
+                default:
+                    DateTime groupStart = group.Key.GuideStart!.Value;
+                    DateTime groupFinish = group.Key.GuideFinish!.Value;
+                    TimeSpan groupDuration = groupFinish - groupStart;
+
+                    TimeSpan perItem = groupDuration / itemsToInclude.Count;
+
+                    DateTimeOffset currentStart = timeZone switch
+                    {
+                        XmltvTimeZone.Utc => new DateTimeOffset(groupStart, TimeSpan.Zero),
+                        _ => new DateTimeOffset(groupStart, TimeSpan.Zero).ToLocalTime()
+                    };
+
+                    DateTimeOffset currentFinish = currentStart + perItem;
+
+                    foreach (PlayoutItem item in itemsToInclude)
+                    {
+                        yield return new ChannelGuideEntry(item, currentStart, currentFinish, false);
+
+                        currentStart = currentFinish;
+                        currentFinish += perItem;
+                    }
+
+                    break;
+            }
+        }
+    }
+}

ErsatzTV.Application/Channels/Commands/BulkDeleteChannels.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.Channels;
+
+public record BulkDeleteChannels(IReadOnlyList<int> ChannelIds) : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/Channels/Commands/BulkDeleteChannelsHandler.cs

@@ -0,0 +1,62 @@
+using System.IO.Abstractions;
+using System.Threading.Channels;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Channel = ErsatzTV.Core.Domain.Channel;
+
+namespace ErsatzTV.Application.Channels;
+
+public class BulkDeleteChannelsHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    ChannelWriter<IBackgroundServiceRequest> workerChannel,
+    IFileSystem fileSystem,
+    ISearchTargets searchTargets)
+    : IRequestHandler<BulkDeleteChannels, Either<BaseError, Unit>>
+{
+    public async Task<Either<BaseError, Unit>> Handle(
+        BulkDeleteChannels request,
+        CancellationToken cancellationToken)
+    {
+        if (request.ChannelIds.Count == 0)
+        {
+            return Left<BaseError, Unit>(BaseError.New("At least one channel id is required"));
+        }
+
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        await using var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken);
+
+        List<int> channelIds = request.ChannelIds.Distinct().ToList();
+        List<Channel> channels = await dbContext.Channels
+            .Where(c => channelIds.Contains(c.Id))
+            .ToListAsync(cancellationToken);
+
+        if (channels.Count != channelIds.Count)
+        {
+            var found = channels.Select(c => c.Id).ToHashSet();
+            int missingId = channelIds.First(id => !found.Contains(id));
+            return Left<BaseError, Unit>(new NotFoundError($"Channel {missingId} does not exist."));
+        }
+
+        dbContext.Channels.RemoveRange(channels);
+        await dbContext.SaveChangesAsync(cancellationToken);
+        await transaction.CommitAsync(cancellationToken);
+
+        searchTargets.SearchTargetsChanged();
+
+        foreach (Channel channel in channels)
+        {
+            string cacheFile = Path.Combine(FileSystemLayout.ChannelGuideCacheFolder, $"{channel.Number}.xml");
+            if (fileSystem.File.Exists(cacheFile))
+            {
+                fileSystem.File.Delete(cacheFile);
+            }
+        }
+
+        await workerChannel.WriteAsync(new RefreshChannelList(), cancellationToken);
+
+        return Right<BaseError, Unit>(Unit.Default);
+    }
+}

ErsatzTV.Application/Channels/Commands/BulkMoveChannelsToGroup.cs

@@ -0,0 +1,6 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.Channels;
+
+public record BulkMoveChannelsToGroup(IReadOnlyList<int> ChannelIds, string Group)
+    : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/Channels/Commands/BulkMoveChannelsToGroupHandler.cs

@@ -0,0 +1,61 @@
+using System.Threading.Channels;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Channels.ChannelValidations;
+using Channel = ErsatzTV.Core.Domain.Channel;
+
+namespace ErsatzTV.Application.Channels;
+
+public class BulkMoveChannelsToGroupHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    ChannelWriter<IBackgroundServiceRequest> workerChannel,
+    ISearchTargets searchTargets)
+    : IRequestHandler<BulkMoveChannelsToGroup, Either<BaseError, Unit>>
+{
+    public async Task<Either<BaseError, Unit>> Handle(
+        BulkMoveChannelsToGroup request,
+        CancellationToken cancellationToken)
+    {
+        if (request.ChannelIds.Count == 0)
+        {
+            return Left<BaseError, Unit>(BaseError.New("At least one channel id is required"));
+        }
+
+        Validation<BaseError, string> groupValidation = ValidateGroup(request.Group);
+        if (groupValidation.IsFail)
+        {
+            return Left<BaseError, Unit>(groupValidation.FailToSeq().Head());
+        }
+
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        await using var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken);
+
+        List<int> channelIds = request.ChannelIds.Distinct().ToList();
+        List<Channel> channels = await dbContext.Channels
+            .Where(c => channelIds.Contains(c.Id))
+            .ToListAsync(cancellationToken);
+
+        if (channels.Count != channelIds.Count)
+        {
+            var found = channels.Select(c => c.Id).ToHashSet();
+            int missingId = channelIds.First(id => !found.Contains(id));
+            return Left<BaseError, Unit>(new NotFoundError($"Channel {missingId} does not exist."));
+        }
+
+        foreach (Channel channel in channels)
+        {
+            channel.Group = request.Group;
+        }
+
+        await dbContext.SaveChangesAsync(cancellationToken);
+        await transaction.CommitAsync(cancellationToken);
+
+        searchTargets.SearchTargetsChanged();
+        await workerChannel.WriteAsync(new RefreshChannelList(), cancellationToken);
+
+        return Right<BaseError, Unit>(Unit.Default);
+    }
+}

ErsatzTV.Application/Channels/Commands/CreateChannelFromLineup.cs

@@ -0,0 +1,56 @@
+using ErsatzTV.Application.Artworks;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.Channels;
+
+public record CreateChannelFromLineup(
+    string Name,
+    string Number,
+    string Group,
+    string Categories,
+    ArtworkContentTypeModel Logo,
+    bool IsEnabled,
+    bool ShowInEpg,
+    int TemplateId,
+    CreateChannelFromLineupAdvancedOptions Advanced,
+    List<CreateChannelFromLineupItem> Lineup) : IRequest<Either<BaseError, CreateChannelFromLineupResponseModel>>;
+
+public record CreateChannelFromLineupAdvancedOptions(
+    PlaybackOrder? PlaybackOrder = null,
+    int? FFmpegProfileId = null,
+    int? WatermarkId = null,
+    int? FallbackFillerId = null,
+    int? PreRollFillerId = null,
+    int? MidRollFillerId = null,
+    int? PostRollFillerId = null,
+    ChannelStreamSelectorMode? StreamSelectorMode = null,
+    string StreamSelector = null,
+    string PreferredAudioLanguageCode = null,
+    string PreferredAudioTitle = null,
+    ChannelPlayoutSource? PlayoutSource = null,
+    ChannelPlayoutMode? PlayoutMode = null,
+    StreamingMode? StreamingMode = null,
+    string PreferredSubtitleLanguageCode = null,
+    ChannelSubtitleMode? SubtitleMode = null,
+    ChannelMusicVideoCreditsMode? MusicVideoCreditsMode = null,
+    string MusicVideoCreditsTemplate = null,
+    ChannelSongVideoMode? SongVideoMode = null,
+    ChannelTranscodeMode? TranscodeMode = null,
+    ChannelIdleBehavior? IdleBehavior = null,
+    bool? ShuffleScheduleItems = null,
+    bool? RandomStartPoint = null,
+    FixedStartTimeBehavior? FixedStartTimeBehavior = null);
+
+public record CreateChannelFromLineupItem(
+    LibraryBrowseMediaType MediaType,
+    CollectionType CollectionType,
+    int? CollectionId,
+    int? MultiCollectionId,
+    int? SmartCollectionId,
+    int? RerunCollectionId,
+    int? MediaItemId,
+    int? PlaylistId);

ErsatzTV.Application/Channels/Commands/CreateChannelFromLineupHandler.cs

@@ -0,0 +1,754 @@
+using System.Globalization;
+using System.Text.RegularExpressions;
+using System.Threading.Channels;
+using ErsatzTV.Application.Playouts;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Channel = ErsatzTV.Core.Domain.Channel;
+
+namespace ErsatzTV.Application.Channels;
+
+public class CreateChannelFromLineupHandler(
+    ChannelWriter<IBackgroundServiceRequest> workerChannel,
+    IDbContextFactory<TvContext> dbContextFactory,
+    ISearchTargets searchTargets,
+    ILogger<CreateChannelFromLineupHandler> logger)
+    : IRequestHandler<CreateChannelFromLineup, Either<BaseError, CreateChannelFromLineupResponseModel>>
+{
+    // The single system playlist group that holds every generated channel-lineup playlist.
+    // Matches the Trakt "Trakt Lists" precedent (DbInitializer + delete guards on IsSystem).
+    private const string SystemPlaylistGroupName = "Channel Lineups";
+
+    public async Task<Either<BaseError, CreateChannelFromLineupResponseModel>> Handle(
+        CreateChannelFromLineup request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        Either<BaseError, PreparedCreate> validation = await Validate(dbContext, request, cancellationToken);
+        return await validation.Match(
+            Left: error => Task.FromResult<Either<BaseError, CreateChannelFromLineupResponseModel>>(error),
+            Right: prepared => PersistAndDispatch(dbContext, prepared, cancellationToken));
+    }
+
+    private async Task<Either<BaseError, CreateChannelFromLineupResponseModel>> PersistAndDispatch(
+        TvContext dbContext,
+        PreparedCreate prepared,
+        CancellationToken cancellationToken)
+    {
+        await using var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken);
+        try
+        {
+            dbContext.Channels.Add(prepared.Channel);
+            if (prepared.Playlist is not null)
+            {
+                dbContext.Playlists.Add(prepared.Playlist);
+            }
+
+            dbContext.ProgramSchedules.Add(prepared.ProgramSchedule);
+            dbContext.Playouts.Add(prepared.Playout);
+
+            await dbContext.SaveChangesAsync(cancellationToken);
+            await transaction.CommitAsync(cancellationToken);
+        }
+        catch (DbUpdateException ex)
+        {
+            await transaction.RollbackAsync(cancellationToken);
+            logger.LogError(ex, "Failed to persist channel created from lineup");
+            return BaseError.New("Unable to create channel from lineup");
+        }
+
+        searchTargets.SearchTargetsChanged();
+        await workerChannel.WriteAsync(
+            new BuildPlayout(prepared.Playout.Id, PlayoutBuildMode.Reset),
+            cancellationToken);
+
+        // Mirror CreateClassicPlayoutHandler: on-demand playouts must be time-shifted to "now" after build.
+        if (prepared.Channel.PlayoutMode is ChannelPlayoutMode.OnDemand)
+        {
+            await workerChannel.WriteAsync(
+                new TimeShiftOnDemandPlayout(prepared.Playout.Id, DateTimeOffset.Now, false),
+                cancellationToken);
+        }
+
+        await workerChannel.WriteAsync(new RefreshChannelList(), cancellationToken);
+
+        return new CreateChannelFromLineupResponseModel(
+            prepared.Channel.Id,
+            prepared.Playlist?.Id,
+            prepared.ProgramSchedule.Id,
+            prepared.Playout.Id);
+    }
+
+    private static async Task<Either<BaseError, PreparedCreate>> Validate(
+        TvContext dbContext,
+        CreateChannelFromLineup request,
+        CancellationToken cancellationToken)
+    {
+        string name = (request.Name ?? string.Empty).Trim();
+        string number = (request.Number ?? string.Empty).Trim();
+        string group = (request.Group ?? string.Empty).Trim();
+        string categories = (request.Categories ?? string.Empty).Trim();
+        CreateChannelFromLineupAdvancedOptions advanced = request.Advanced ?? new CreateChannelFromLineupAdvancedOptions();
+
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            return BaseError.New("Channel name is required");
+        }
+
+        if (name.Length > 50)
+        {
+            return BaseError.New("Channel name must be 50 characters or fewer");
+        }
+
+        if (string.IsNullOrWhiteSpace(group))
+        {
+            return BaseError.New("Channel group is required");
+        }
+
+        if (!Regex.IsMatch(number, Channel.NumberValidator))
+        {
+            return BaseError.New("Invalid channel number; two decimals are allowed for subchannels");
+        }
+
+        if (await dbContext.Channels.AnyAsync(c => c.Number == number, cancellationToken))
+        {
+            return BaseError.New("Channel number must be unique");
+        }
+
+        if (!request.IsEnabled && request.ShowInEpg)
+        {
+            return BaseError.New("Disabled channels cannot be shown in EPG");
+        }
+
+        if (!string.IsNullOrWhiteSpace(request.Logo?.Path) &&
+            Uri.TryCreate(request.Logo.Path, UriKind.Absolute, out _) &&
+            !Artwork.IsExternalUrl(request.Logo.Path))
+        {
+            return BaseError.New("External logo url is invalid");
+        }
+
+        if (request.Lineup is null || request.Lineup.Count == 0)
+        {
+            return BaseError.New("Lineup must contain at least one item");
+        }
+
+        ChannelTemplate template = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SingleOrDefaultAsync(t => t.Id == request.TemplateId, cancellationToken);
+        if (template is null)
+        {
+            return new NotFoundError($"Channel template {request.TemplateId} does not exist.");
+        }
+
+        int ffmpegProfileId = advanced.FFmpegProfileId ?? template.FFmpegProfileId;
+        int? fallbackFillerId = advanced.FallbackFillerId ?? template.FallbackFillerId;
+        int? preRollFillerId = advanced.PreRollFillerId ?? template.PreRollFillerId;
+        int? midRollFillerId = advanced.MidRollFillerId ?? template.MidRollFillerId;
+        int? postRollFillerId = advanced.PostRollFillerId ?? template.PostRollFillerId;
+        PlaybackOrder playbackOrder = advanced.PlaybackOrder ?? PlaybackOrder.Chronological;
+        ChannelPlayoutSource playoutSource = advanced.PlayoutSource ?? template.PlayoutSource;
+
+        // Mirror channels need special MirrorSourceChannelId plumbing (see CreateChannelHandler);
+        // this endpoint only builds generated playouts.
+        if (playoutSource is ChannelPlayoutSource.Mirror)
+        {
+            return BaseError.New("Mirror playout source is not supported by this endpoint");
+        }
+
+        Either<BaseError, Unit> referenceValidation = await ValidateReferences(
+            dbContext,
+            advanced,
+            template,
+            cancellationToken);
+        foreach (BaseError error in referenceValidation.LeftToSeq())
+        {
+            return error;
+        }
+
+        // Normalize + validate every lineup entry once, so validation and build see the same data.
+        var normalized = new List<NormalizedLineupItem>();
+        for (int i = 0; i < request.Lineup.Count; i++)
+        {
+            Either<BaseError, NormalizedLineupItem> itemValidation =
+                await NormalizeLineupItem(dbContext, request.Lineup[i], i, cancellationToken);
+            foreach (BaseError error in itemValidation.LeftToSeq())
+            {
+                return error;
+            }
+
+            foreach (NormalizedLineupItem item in itemValidation.RightToSeq())
+            {
+                normalized.Add(item);
+            }
+        }
+
+        bool multiItem = normalized.Count >= 2;
+
+        // MultiCollection entries only support Shuffle / ShuffleInOrder (mirrors PlayoutModeMustBeValid).
+        if (normalized.Any(i => i.CollectionType is CollectionType.MultiCollection) &&
+            playbackOrder is not (PlaybackOrder.Shuffle or PlaybackOrder.ShuffleInOrder))
+        {
+            return BaseError.New($"Invalid playback order for multi collection: '{playbackOrder}'");
+        }
+
+        if (multiItem)
+        {
+            // The generated playlist cannot express rerun collections or nested playlists
+            // (PlaylistItem + CollectionKey.ForPlaylistItem lack those fields).
+            for (int i = 0; i < normalized.Count; i++)
+            {
+                if (normalized[i].CollectionType is CollectionType.RerunFirstRun or CollectionType.Playlist)
+                {
+                    return BaseError.New(
+                        $"lineup[{normalized[i].Index}]: rerun collections and playlists are only " +
+                        "supported as a single-item lineup");
+                }
+            }
+        }
+
+        Channel channel = BuildChannel(
+            request,
+            template,
+            advanced,
+            name,
+            number,
+            group,
+            categories,
+            ffmpegProfileId,
+            fallbackFillerId);
+
+        string scheduleName = await DeCollideName(
+            GeneratedName(number, name, "Schedule"),
+            (candidate, ct) => dbContext.ProgramSchedules.AnyAsync(ps => ps.Name == candidate, ct),
+            cancellationToken);
+
+        ProgramSchedule schedule = BuildProgramSchedule(scheduleName, template, advanced);
+
+        Playlist playlist = null;
+        ProgramScheduleItemFlood floodItem = BuildFloodBase(
+            playbackOrder,
+            advanced,
+            template,
+            fallbackFillerId,
+            preRollFillerId,
+            midRollFillerId,
+            postRollFillerId);
+
+        if (multiItem)
+        {
+            playlist = await BuildPlaylist(dbContext, number, name, normalized, playbackOrder, cancellationToken);
+            floodItem.CollectionType = CollectionType.Playlist;
+            floodItem.Playlist = playlist;
+        }
+        else
+        {
+            NormalizedLineupItem only = normalized[0];
+            floodItem.CollectionType = only.CollectionType;
+            floodItem.CollectionId = only.CollectionId;
+            floodItem.MultiCollectionId = only.MultiCollectionId;
+            floodItem.SmartCollectionId = only.SmartCollectionId;
+            floodItem.RerunCollectionId = only.RerunCollectionId;
+            floodItem.MediaItemId = only.MediaItemId;
+            floodItem.PlaylistId = only.PlaylistId;
+        }
+
+        schedule.Items = [floodItem];
+
+        var playout = new Playout
+        {
+            Channel = channel,
+            ProgramSchedule = schedule,
+            ScheduleKind = PlayoutScheduleKind.Classic
+        };
+
+        return new PreparedCreate(channel, playlist, schedule, playout);
+    }
+
+    private static async Task<Playlist> BuildPlaylist(
+        TvContext dbContext,
+        string channelNumber,
+        string channelName,
+        List<NormalizedLineupItem> lineup,
+        PlaybackOrder playbackOrder,
+        CancellationToken cancellationToken)
+    {
+        // Reuse the single system playlist group, creating it on first use.
+        PlaylistGroup playlistGroup = await dbContext.PlaylistGroups
+            .FirstOrDefaultAsync(pg => pg.IsSystem && pg.Name == SystemPlaylistGroupName, cancellationToken);
+        playlistGroup ??= new PlaylistGroup { Name = SystemPlaylistGroupName, IsSystem = true };
+
+        string playlistName = await DeCollideName(
+            GeneratedName(channelNumber, channelName, "Lineup"),
+            (candidate, ct) => dbContext.Playlists.AnyAsync(
+                p => p.PlaylistGroupId == playlistGroup.Id && p.Name == candidate,
+                ct),
+            cancellationToken);
+
+        var playlist = new Playlist
+        {
+            Name = playlistName,
+            IsSystem = true,
+            PlaylistGroup = playlistGroup,
+            PlaylistGroupId = playlistGroup.Id,
+            Items = []
+        };
+
+        int index = 1;
+        foreach (NormalizedLineupItem item in lineup)
+        {
+            playlist.Items.Add(new PlaylistItem
+            {
+                Playlist = playlist,
+                Index = index++,
+                CollectionType = item.CollectionType,
+                CollectionId = item.CollectionId,
+                MultiCollectionId = item.MultiCollectionId,
+                SmartCollectionId = item.SmartCollectionId,
+                MediaItemId = item.MediaItemId,
+                PlaybackOrder = playbackOrder,
+
+                // Play every item in each entry before advancing so lineup order is honored
+                // (PlaylistEnumerator round-robins one-per-entry unless PlayAll/Count).
+                PlayAll = true,
+                IncludeInProgramGuide = true
+            });
+        }
+
+        return playlist;
+    }
+
+    private static Channel BuildChannel(
+        CreateChannelFromLineup request,
+        ChannelTemplate template,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        string name,
+        string number,
+        string group,
+        string categories,
+        int ffmpegProfileId,
+        int? fallbackFillerId)
+    {
+        var artwork = new List<Artwork>();
+        if (!string.IsNullOrWhiteSpace(request.Logo?.Path))
+        {
+            string logo = request.Logo.Path;
+            if (logo.StartsWith("iptv/logos/", StringComparison.Ordinal))
+            {
+                logo = logo.Replace("iptv/logos/", string.Empty);
+            }
+
+            artwork.Add(new Artwork
+            {
+                Path = logo,
+                ArtworkKind = ArtworkKind.Logo,
+                OriginalContentType = !string.IsNullOrEmpty(request.Logo.ContentType) ? request.Logo.ContentType : null,
+                DateAdded = DateTime.UtcNow,
+                DateUpdated = DateTime.UtcNow
+            });
+        }
+
+        return new Channel(Guid.NewGuid())
+        {
+            Name = name,
+            Number = number,
+            SortNumber = double.Parse(number, CultureInfo.InvariantCulture),
+            Group = group,
+            Categories = categories,
+            FFmpegProfileId = ffmpegProfileId,
+            SlugSeconds = null,
+            PlayoutSource = advanced.PlayoutSource ?? template.PlayoutSource,
+            PlayoutMode = advanced.PlayoutMode ?? template.PlayoutMode,
+            StreamingMode = advanced.StreamingMode ?? template.StreamingMode,
+            WatermarkId = advanced.WatermarkId ?? template.WatermarkId,
+            FallbackFillerId = fallbackFillerId,
+            Artwork = artwork,
+            StreamSelectorMode = advanced.StreamSelectorMode ?? template.StreamSelectorMode,
+            StreamSelector = advanced.StreamSelector ?? template.StreamSelector ?? string.Empty,
+            PreferredAudioLanguageCode =
+                advanced.PreferredAudioLanguageCode ?? template.PreferredAudioLanguageCode ?? string.Empty,
+            PreferredAudioTitle = advanced.PreferredAudioTitle ?? template.PreferredAudioTitle ?? string.Empty,
+            PreferredSubtitleLanguageCode =
+                advanced.PreferredSubtitleLanguageCode ?? template.PreferredSubtitleLanguageCode ?? string.Empty,
+            SubtitleMode = advanced.SubtitleMode ?? template.SubtitleMode,
+            MusicVideoCreditsMode = advanced.MusicVideoCreditsMode ?? template.MusicVideoCreditsMode,
+            MusicVideoCreditsTemplate =
+                advanced.MusicVideoCreditsTemplate ?? template.MusicVideoCreditsTemplate ?? string.Empty,
+            SongVideoMode = advanced.SongVideoMode ?? template.SongVideoMode,
+            TranscodeMode = advanced.TranscodeMode ?? template.TranscodeMode,
+            IdleBehavior = advanced.IdleBehavior ?? template.IdleBehavior,
+            IsEnabled = request.IsEnabled,
+            ShowInEpg = request.IsEnabled && request.ShowInEpg
+        };
+    }
+
+    private static ProgramSchedule BuildProgramSchedule(
+        string scheduleName,
+        ChannelTemplate template,
+        CreateChannelFromLineupAdvancedOptions advanced) =>
+        new()
+        {
+            Name = scheduleName,
+            KeepMultiPartEpisodesTogether = true,
+            TreatCollectionsAsShows = true,
+            ShuffleScheduleItems = advanced.ShuffleScheduleItems ?? template.ShuffleScheduleItems,
+            RandomStartPoint = advanced.RandomStartPoint ?? template.RandomStartPoint,
+            FixedStartTimeBehavior = advanced.FixedStartTimeBehavior ?? template.FixedStartTimeBehavior,
+            Items = []
+        };
+
+    private static ProgramScheduleItemFlood BuildFloodBase(
+        PlaybackOrder playbackOrder,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        ChannelTemplate template,
+        int? fallbackFillerId,
+        int? preRollFillerId,
+        int? midRollFillerId,
+        int? postRollFillerId) =>
+        new()
+        {
+            Index = 1,
+            PlaybackOrder = playbackOrder,
+            GuideMode = GuideMode.Normal,
+            CustomTitle = string.Empty,
+            SearchTitle = string.Empty,
+            SearchQuery = string.Empty,
+            PreRollFillerId = preRollFillerId,
+            MidRollFillerId = midRollFillerId,
+            PostRollFillerId = postRollFillerId,
+            FallbackFillerId = fallbackFillerId,
+            PreferredAudioLanguageCode =
+                advanced.PreferredAudioLanguageCode ?? template.PreferredAudioLanguageCode ?? string.Empty,
+            PreferredAudioTitle = advanced.PreferredAudioTitle ?? template.PreferredAudioTitle ?? string.Empty,
+            PreferredSubtitleLanguageCode =
+                advanced.PreferredSubtitleLanguageCode ?? template.PreferredSubtitleLanguageCode ?? string.Empty,
+            SubtitleMode = advanced.SubtitleMode ?? template.SubtitleMode
+        };
+
+    private static string GeneratedName(string channelNumber, string channelName, string suffix)
+    {
+        string prefix = $"{channelNumber} {channelName}".Trim();
+        int maxPrefixLength = Math.Max(0, 50 - suffix.Length - 1);
+        if (prefix.Length > maxPrefixLength)
+        {
+            prefix = prefix[..maxPrefixLength].TrimEnd();
+        }
+
+        return $"{prefix} {suffix}".Trim();
+    }
+
+    // De-collide a generated (already <= 50 char) name against a unique index by appending " 2", " 3", ...
+    // rather than leaking a raw UNIQUE-constraint failure.
+    private static async Task<string> DeCollideName(
+        string baseName,
+        Func<string, CancellationToken, Task<bool>> exists,
+        CancellationToken cancellationToken)
+    {
+        if (!await exists(baseName, cancellationToken))
+        {
+            return baseName;
+        }
+
+        for (int n = 2; ; n++)
+        {
+            string suffix = $" {n}";
+            string candidate = baseName.Length + suffix.Length > 50
+                ? baseName[..(50 - suffix.Length)].TrimEnd() + suffix
+                : baseName + suffix;
+
+            if (!await exists(candidate, cancellationToken))
+            {
+                return candidate;
+            }
+        }
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateReferences(
+        TvContext dbContext,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        ChannelTemplate template,
+        CancellationToken cancellationToken)
+    {
+        int ffmpegProfileId = advanced.FFmpegProfileId ?? template.FFmpegProfileId;
+        if (!await dbContext.FFmpegProfiles.AnyAsync(p => p.Id == ffmpegProfileId, cancellationToken))
+        {
+            return new NotFoundError($"FFmpegProfile {ffmpegProfileId} does not exist.");
+        }
+
+        Either<BaseError, Unit> channelReferences = await ValidateChannelReferences(
+            dbContext,
+            advanced.WatermarkId ?? template.WatermarkId,
+            advanced.FallbackFillerId ?? template.FallbackFillerId,
+            cancellationToken);
+        foreach (BaseError error in channelReferences.LeftToSeq())
+        {
+            return error;
+        }
+
+        Either<BaseError, Unit> itemFillers = await ValidateItemFillers(
+            dbContext,
+            advanced.PreRollFillerId ?? template.PreRollFillerId,
+            advanced.MidRollFillerId ?? template.MidRollFillerId,
+            advanced.PostRollFillerId ?? template.PostRollFillerId,
+            cancellationToken);
+        foreach (BaseError error in itemFillers.LeftToSeq())
+        {
+            return error;
+        }
+
+        return Unit.Default;
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateChannelReferences(
+        TvContext dbContext,
+        int? watermarkId,
+        int? fallbackFillerId,
+        CancellationToken cancellationToken)
+    {
+        if (watermarkId.HasValue &&
+            !await dbContext.ChannelWatermarks.AnyAsync(w => w.Id == watermarkId.Value, cancellationToken))
+        {
+            return new NotFoundError($"Watermark {watermarkId.Value} does not exist.");
+        }
+
+        if (fallbackFillerId.HasValue && !await dbContext.FillerPresets.AnyAsync(
+                fp => fp.Id == fallbackFillerId.Value && fp.FillerKind == FillerKind.Fallback,
+                cancellationToken))
+        {
+            return new NotFoundError($"Fallback filler {fallbackFillerId.Value} does not exist.");
+        }
+
+        return Unit.Default;
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateItemFillers(
+        TvContext dbContext,
+        int? preRollFillerId,
+        int? midRollFillerId,
+        int? postRollFillerId,
+        CancellationToken cancellationToken)
+    {
+        if (preRollFillerId.HasValue && !await FillerExists(dbContext, preRollFillerId.Value, FillerKind.PreRoll, cancellationToken))
+        {
+            return new NotFoundError($"Pre-roll filler {preRollFillerId.Value} does not exist.");
+        }
+
+        if (midRollFillerId.HasValue && !await FillerExists(dbContext, midRollFillerId.Value, FillerKind.MidRoll, cancellationToken))
+        {
+            return new NotFoundError($"Mid-roll filler {midRollFillerId.Value} does not exist.");
+        }
+
+        if (postRollFillerId.HasValue && !await FillerExists(dbContext, postRollFillerId.Value, FillerKind.PostRoll, cancellationToken))
+        {
+            return new NotFoundError($"Post-roll filler {postRollFillerId.Value} does not exist.");
+        }
+
+        return Unit.Default;
+    }
+
+    private static Task<bool> FillerExists(
+        TvContext dbContext,
+        int id,
+        FillerKind fillerKind,
+        CancellationToken cancellationToken) =>
+        dbContext.FillerPresets.AnyAsync(fp => fp.Id == id && fp.FillerKind == fillerKind, cancellationToken);
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> NormalizeLineupItem(
+        TvContext dbContext,
+        CreateChannelFromLineupItem item,
+        int index,
+        CancellationToken cancellationToken)
+    {
+        int providedIds = new int?[]
+        {
+            item.CollectionId,
+            item.MultiCollectionId,
+            item.SmartCollectionId,
+            item.RerunCollectionId,
+            item.MediaItemId,
+            item.PlaylistId
+        }.Count(id => id.HasValue);
+
+        if (providedIds != 1)
+        {
+            return BaseError.New($"lineup[{index}] must provide exactly one typed id.");
+        }
+
+        switch (item.MediaType)
+        {
+            case LibraryBrowseMediaType.Movie:
+                return await NormalizeMediaItem(
+                    dbContext.Movies, item, CollectionType.Movie, index, "Movie", cancellationToken);
+            case LibraryBrowseMediaType.TelevisionShow:
+                return await NormalizeMediaItem(
+                    dbContext.Shows, item, CollectionType.TelevisionShow, index, "TelevisionShow", cancellationToken);
+            case LibraryBrowseMediaType.TelevisionSeason:
+                return await NormalizeMediaItem(
+                    dbContext.Seasons, item, CollectionType.TelevisionSeason, index, "TelevisionSeason", cancellationToken);
+            case LibraryBrowseMediaType.Artist:
+                return await NormalizeMediaItem(
+                    dbContext.Artists, item, CollectionType.Artist, index, "Artist", cancellationToken);
+            case LibraryBrowseMediaType.Collection:
+                if (item.CollectionType != CollectionType.Collection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.CollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "collectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.Collections,
+                    item.CollectionId.Value,
+                    $"lineup[{index}] Collection",
+                    new NormalizedLineupItem(index, CollectionType.Collection, CollectionId: item.CollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.SmartCollection:
+                if (item.CollectionType != CollectionType.SmartCollection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.SmartCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "smartCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.SmartCollections,
+                    item.SmartCollectionId.Value,
+                    $"lineup[{index}] SmartCollection",
+                    new NormalizedLineupItem(index, CollectionType.SmartCollection, SmartCollectionId: item.SmartCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.MultiCollection:
+                if (item.CollectionType != CollectionType.MultiCollection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.MultiCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "multiCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.MultiCollections,
+                    item.MultiCollectionId.Value,
+                    $"lineup[{index}] MultiCollection",
+                    new NormalizedLineupItem(index, CollectionType.MultiCollection, MultiCollectionId: item.MultiCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.RerunCollection:
+                if (item.CollectionType != CollectionType.RerunFirstRun)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.RerunCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "rerunCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.RerunCollections,
+                    item.RerunCollectionId.Value,
+                    $"lineup[{index}] RerunCollection",
+                    new NormalizedLineupItem(index, CollectionType.RerunFirstRun, RerunCollectionId: item.RerunCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.Playlist:
+                if (item.CollectionType != CollectionType.Playlist)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.PlaylistId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "playlistId");
+                }
+
+                return await ExistsThen(
+                    dbContext.Playlists,
+                    item.PlaylistId.Value,
+                    $"lineup[{index}] Playlist",
+                    new NormalizedLineupItem(index, CollectionType.Playlist, PlaylistId: item.PlaylistId),
+                    cancellationToken);
+            default:
+                return BaseError.New($"lineup[{index}] has an unsupported media type '{item.MediaType}'.");
+        }
+    }
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> NormalizeMediaItem<TEntity>(
+        DbSet<TEntity> set,
+        CreateChannelFromLineupItem item,
+        CollectionType expectedType,
+        int index,
+        string label,
+        CancellationToken cancellationToken)
+        where TEntity : class
+    {
+        if (item.CollectionType != expectedType)
+        {
+            return Mismatch(index, item);
+        }
+
+        if (!item.MediaItemId.HasValue)
+        {
+            return WrongId(index, item.MediaType, "mediaItemId");
+        }
+
+        return await ExistsThen(
+            set,
+            item.MediaItemId.Value,
+            $"lineup[{index}] {label}",
+            new NormalizedLineupItem(index, expectedType, MediaItemId: item.MediaItemId),
+            cancellationToken);
+    }
+
+    private static BaseError Mismatch(int index, CreateChannelFromLineupItem item) =>
+        BaseError.New(
+            $"lineup[{index}]: media type '{item.MediaType}' does not match collection type '{item.CollectionType}'.");
+
+    private static BaseError WrongId(int index, LibraryBrowseMediaType mediaType, string expectedField) =>
+        BaseError.New($"lineup[{index}]: media type '{mediaType}' requires a {expectedField}.");
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> ExistsThen<TEntity>(
+        DbSet<TEntity> set,
+        int id,
+        string label,
+        NormalizedLineupItem normalized,
+        CancellationToken cancellationToken)
+        where TEntity : class
+    {
+        bool exists = await set.AsNoTracking()
+            .AnyAsync(e => EF.Property<int>(e, "Id") == id, cancellationToken);
+        return exists
+            ? normalized
+            : new NotFoundError($"{label} {id} does not exist.");
+    }
+
+    private sealed record NormalizedLineupItem(
+        int Index,
+        CollectionType CollectionType,
+        int? CollectionId = null,
+        int? MultiCollectionId = null,
+        int? SmartCollectionId = null,
+        int? RerunCollectionId = null,
+        int? MediaItemId = null,
+        int? PlaylistId = null);
+
+    private sealed record PreparedCreate(
+        Channel Channel,
+        Playlist Playlist,
+        ProgramSchedule ProgramSchedule,
+        Playout Playout);
+}

ErsatzTV.Application/Channels/Commands/RefreshChannelDataHandler.cs

@@ -129,89 +129,7 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
             List<Playout> playouts = await dbContext.Playouts
                 .AsNoTracking()
                 .Filter(pi => pi.Channel.Number == (mirrorChannelNumber ?? request.ChannelNumber))
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Episode).EpisodeMetadata)
-                .ThenInclude(em => em.Guids)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Episode).EpisodeMetadata)
-                .ThenInclude(em => em.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Episode).Season)
-                .ThenInclude(s => s.Show)
-                .ThenInclude(s => s.ShowMetadata)
-                .ThenInclude(sm => sm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Episode).Season)
-                .ThenInclude(s => s.Show)
-                .ThenInclude(s => s.ShowMetadata)
-                .ThenInclude(sm => sm.Genres)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Episode).Season)
-                .ThenInclude(s => s.Show)
-                .ThenInclude(s => s.ShowMetadata)
-                .ThenInclude(sm => sm.Guids)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Movie).MovieMetadata)
-                .ThenInclude(mm => mm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Movie).MovieMetadata)
-                .ThenInclude(mm => mm.Genres)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Movie).MovieMetadata)
-                .ThenInclude(mm => mm.Guids)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).MusicVideoMetadata)
-                .ThenInclude(mm => mm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).MusicVideoMetadata)
-                .ThenInclude(mvm => mvm.Genres)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).MusicVideoMetadata)
-                .ThenInclude(mvm => mvm.Studios)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).MusicVideoMetadata)
-                .ThenInclude(mvm => mvm.Directors)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).MusicVideoMetadata)
-                .ThenInclude(mvm => mvm.Artists)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as MusicVideo).Artist)
-                .ThenInclude(a => a.ArtistMetadata)
-                .ThenInclude(am => am.Genres)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as OtherVideo).OtherVideoMetadata)
-                .ThenInclude(vm => vm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as RemoteStream).RemoteStreamMetadata)
-                .ThenInclude(vm => vm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Song).SongMetadata)
-                .ThenInclude(vm => vm.Artwork)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Song).SongMetadata)
-                .ThenInclude(sm => sm.Genres)
-                .Include(p => p.Items)
-                .ThenInclude(i => i.MediaItem)
-                .ThenInclude(i => (i as Song).SongMetadata)
-                .ThenInclude(sm => sm.Studios)
+                .IncludeGuideMetadata()
                 .AsSplitQuery()
                 .ToListAsync(cancellationToken);
 
@@ -244,8 +162,9 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
                             item.Finish += playoutOffset;
                         }
 
-                        await WritePlayoutXml(
+                        await WriteScheduleXml(
                             request,
+                            playout.ScheduleKind,
                             floodSorted,
                             templateContext,
                             movieTemplate,
@@ -270,8 +189,9 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
                             item.Finish += playoutOffset;
                         }
 
-                        await WriteBlockPlayoutXml(
+                        await WriteScheduleXml(
                             request,
+                            playout.ScheduleKind,
                             blockSorted,
                             templateContext,
                             movieTemplate,
@@ -294,8 +214,9 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
                             item.Finish += playoutOffset;
                         }
 
-                        await WritePlayoutXml(
+                        await WriteScheduleXml(
                             request,
+                            playout.ScheduleKind,
                             externalJsonSorted,
                             templateContext,
                             movieTemplate,
@@ -324,100 +245,9 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
         }
     }
 
-    private async Task WritePlayoutXml(
-        RefreshChannelData request,
-        List<PlayoutItem> sorted,
-        XmlTemplateContext templateContext,
-        Template movieTemplate,
-        Template episodeTemplate,
-        Template musicVideoTemplate,
-        Template songTemplate,
-        Template otherVideoTemplate,
-        Template remoteStreamTemplate,
-        XmlMinifier minifier,
-        XmlWriter xml,
-        CancellationToken cancellationToken)
-    {
-        XmltvTimeZone xmltvTimeZone = await _configElementRepository
-            .GetValue<XmltvTimeZone>(ConfigElementKey.XmltvTimeZone, cancellationToken)
-            .IfNoneAsync(XmltvTimeZone.Local);
-
-        // skip all filler that isn't pre-roll
-        var i = 0;
-        while (i < sorted.Count && sorted[i].FillerKind != FillerKind.None &&
-               sorted[i].FillerKind != FillerKind.PreRoll)
-        {
-            i++;
-        }
-
-        while (i < sorted.Count)
-        {
-            PlayoutItem startItem = sorted[i];
-            int j = i;
-            while (sorted[j].FillerKind != FillerKind.None && j + 1 < sorted.Count)
-            {
-                j++;
-            }
-
-            PlayoutItem displayItem = sorted[j];
-            bool hasCustomTitle = !string.IsNullOrWhiteSpace(startItem.CustomTitle);
-
-            int finishIndex = j;
-            while (finishIndex + 1 < sorted.Count && (sorted[finishIndex + 1].GuideGroup == startItem.GuideGroup
-                                                      || sorted[finishIndex + 1].FillerKind is FillerKind.GuideMode
-                                                          or FillerKind.PostRoll or FillerKind.Tail
-                                                          or FillerKind.Fallback or FillerKind.DecoDefault))
-            {
-                finishIndex++;
-            }
-
-            PlayoutItem finishItem = sorted[finishIndex];
-            i = finishIndex;
-
-            DateTimeOffset startTime = xmltvTimeZone switch
-            {
-                XmltvTimeZone.Utc => new DateTimeOffset(startItem.Start, TimeSpan.Zero),
-                _ => startItem.StartOffset
-            };
-
-            DateTimeOffset stopTime = (xmltvTimeZone, displayItem.GuideFinishOffset.HasValue) switch
-            {
-                (XmltvTimeZone.Utc, true) => new DateTimeOffset(displayItem.GuideFinish!.Value, TimeSpan.Zero),
-                (XmltvTimeZone.Utc, false) => new DateTimeOffset(finishItem.Finish, TimeSpan.Zero),
-                (_, true) => displayItem.GuideFinishOffset!.Value,
-                (_, false) => finishItem.FinishOffset
-            };
-
-            string start = startTime
-                .ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                .Replace(":", string.Empty);
-
-            string stop = stopTime
-                .ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                .Replace(":", string.Empty);
-
-            await WriteItemToXml(
-                request,
-                displayItem,
-                start,
-                stop,
-                hasCustomTitle,
-                templateContext,
-                movieTemplate,
-                episodeTemplate,
-                musicVideoTemplate,
-                songTemplate,
-                otherVideoTemplate,
-                remoteStreamTemplate,
-                minifier,
-                xml);
-
-            i++;
-        }
-    }
-
-    private async Task WriteBlockPlayoutXml(
+    private async Task WriteScheduleXml(
         RefreshChannelData request,
+        PlayoutScheduleKind scheduleKind,
         List<PlayoutItem> sorted,
         XmlTemplateContext templateContext,
         Template movieTemplate,
@@ -438,98 +268,36 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
             .GetValue<XmltvBlockBehavior>(ConfigElementKey.XmltvBlockBehavior, cancellationToken)
             .IfNoneAsync(XmltvBlockBehavior.SplitTimeEvenly);
 
-        var groups = sorted.GroupBy(s => new { s.GuideStart, s.GuideFinish, s.GuideGroup });
-        foreach (var group in groups)
+        // guide-group / filler-merge logic is shared with the JSON guide query so the two cannot drift
+        foreach (ChannelGuideEntry entry in ChannelGuideProjector.Project(
+                     scheduleKind,
+                     sorted,
+                     xmltvTimeZone,
+                     xmltvBlockBehavior))
         {
-            var itemsToInclude = group.Filter(g => g.FillerKind is FillerKind.None).ToList();
-            if (itemsToInclude.Count == 0)
-            {
-                continue;
-            }
+            string start = entry.Start
+                .ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
+                .Replace(":", string.Empty);
 
-            switch (xmltvBlockBehavior)
-            {
-                case XmltvBlockBehavior.UseActualTimes:
-                    foreach (PlayoutItem item in itemsToInclude)
-                    {
-                        DateTimeOffset actualStart = xmltvTimeZone switch
-                        {
-                            XmltvTimeZone.Utc => new DateTimeOffset(item.Start, TimeSpan.Zero),
-                            _ => new DateTimeOffset(item.Start, TimeSpan.Zero).ToLocalTime()
-                        };
+            string stop = entry.Stop
+                .ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
+                .Replace(":", string.Empty);
 
-                        DateTimeOffset actualFinish = xmltvTimeZone switch
-                        {
-                            XmltvTimeZone.Utc => new DateTimeOffset(item.Finish, TimeSpan.Zero),
-                            _ => new DateTimeOffset(item.Finish, TimeSpan.Zero).ToLocalTime()
-                        };
-
-                        string start = actualStart.ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                            .Replace(":", string.Empty);
-                        string stop = actualFinish.ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                            .Replace(":", string.Empty);
-
-                        await WriteItemToXml(
-                            request,
-                            item,
-                            start,
-                            stop,
-                            false,
-                            templateContext,
-                            movieTemplate,
-                            episodeTemplate,
-                            musicVideoTemplate,
-                            songTemplate,
-                            otherVideoTemplate,
-                            remoteStreamTemplate,
-                            minifier,
-                            xml);
-                    }
-                    break;
-                case XmltvBlockBehavior.SplitTimeEvenly:
-                default:
-                    DateTime groupStart = group.Key.GuideStart!.Value;
-                    DateTime groupFinish = group.Key.GuideFinish!.Value;
-                    TimeSpan groupDuration = groupFinish - groupStart;
-
-                    TimeSpan perItem = groupDuration / itemsToInclude.Count;
-
-                    DateTimeOffset currentStart = xmltvTimeZone switch
-                    {
-                        XmltvTimeZone.Utc => new DateTimeOffset(groupStart, TimeSpan.Zero),
-                        _ => new DateTimeOffset(groupStart, TimeSpan.Zero).ToLocalTime()
-                    };
-
-                    DateTimeOffset currentFinish = currentStart + perItem;
-
-                    foreach (PlayoutItem item in itemsToInclude)
-                    {
-                        string start = currentStart.ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                            .Replace(":", string.Empty);
-                        string stop = currentFinish.ToString("yyyyMMddHHmmss zzz", CultureInfo.InvariantCulture)
-                            .Replace(":", string.Empty);
-
-                        await WriteItemToXml(
-                            request,
-                            item,
-                            start,
-                            stop,
-                            false,
-                            templateContext,
-                            movieTemplate,
-                            episodeTemplate,
-                            musicVideoTemplate,
-                            songTemplate,
-                            otherVideoTemplate,
-                            remoteStreamTemplate,
-                            minifier,
-                            xml);
-
-                        currentStart = currentFinish;
-                        currentFinish += perItem;
-                    }
-                    break;
-            }
+            await WriteItemToXml(
+                request,
+                entry.DisplayItem,
+                start,
+                stop,
+                entry.HasCustomTitle,
+                templateContext,
+                movieTemplate,
+                episodeTemplate,
+                musicVideoTemplate,
+                songTemplate,
+                otherVideoTemplate,
+                remoteStreamTemplate,
+                minifier,
+                xml);
         }
     }
 
@@ -549,8 +317,8 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
         XmlMinifier minifier,
         XmlWriter xml)
     {
-        string title = GetTitle(displayItem);
-        string subtitle = GetSubtitle(displayItem);
+        string title = ChannelGuideMetadata.GetTitle(displayItem);
+        string subtitle = ChannelGuideMetadata.GetSubtitle(displayItem);
 
         Option<string> maybeTemplateOutput = displayItem.MediaItem switch
         {
@@ -1117,51 +885,6 @@ public class RefreshChannelDataHandler : IRequestHandler<RefreshChannelData>
         return artworkPath;
     }
 
-    private static string GetTitle(PlayoutItem playoutItem)
-    {
-        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
-        {
-            return playoutItem.CustomTitle;
-        }
-
-        return playoutItem.MediaItem switch
-        {
-            Movie m => m.MovieMetadata.HeadOrNone().Map(mm => mm.Title ?? string.Empty)
-                .IfNone("[unknown movie]"),
-            Episode e => e.Season.Show.ShowMetadata.HeadOrNone().Map(em => em.Title ?? string.Empty)
-                .IfNone("[unknown show]"),
-            MusicVideo mv => mv.Artist.ArtistMetadata.HeadOrNone().Map(am => am.Title ?? string.Empty)
-                .IfNone("[unknown artist]"),
-            OtherVideo ov => ov.OtherVideoMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
-                .IfNone("[unknown video]"),
-            RemoteStream rs => rs.RemoteStreamMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
-                .IfNone("[unknown remote stream]"),
-            _ => "[unknown]"
-        };
-    }
-
-    private static string GetSubtitle(PlayoutItem playoutItem)
-    {
-        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
-        {
-            return string.Empty;
-        }
-
-        return playoutItem.MediaItem switch
-        {
-            Episode e => e.EpisodeMetadata.HeadOrNone().Match(
-                em => em.Title ?? string.Empty,
-                () => string.Empty),
-            MusicVideo mv => mv.MusicVideoMetadata.HeadOrNone().Match(
-                mvm => mvm.Title ?? string.Empty,
-                () => string.Empty),
-            Song s => s.SongMetadata.HeadOrNone().Match(
-                mvm => mvm.Title ?? string.Empty,
-                () => string.Empty),
-            _ => string.Empty
-        };
-    }
-
     private static string GetPrioritizedArtworkPath(Metadata metadata)
     {
         Option<string> maybeArtwork = Optional(metadata.Artwork).Flatten()

ErsatzTV.Application/Channels/Commands/UpdateChannelNumbersHandler.cs

@@ -1,6 +1,8 @@
 using System.Globalization;
+using System.Text.RegularExpressions;
 using System.Threading.Channels;
 using ErsatzTV.Core;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Infrastructure.Data;
 using Microsoft.EntityFrameworkCore;
 using Channel = ErsatzTV.Core.Domain.Channel;
@@ -14,18 +16,41 @@ public class UpdateChannelNumbersHandler(
 {
     public async Task<Option<BaseError>> Handle(UpdateChannelNumbers request, CancellationToken cancellationToken)
     {
+        Option<BaseError> validationError = ValidateRequest(request);
+        if (validationError.IsSome)
+        {
+            return validationError;
+        }
+
         await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
         await using var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken);
 
         try
         {
             var numberUpdates = request.Channels.ToDictionary(c => c.Id, c => c.Number);
-            var channelIds = numberUpdates.Keys;
+            List<int> channelIds = numberUpdates.Keys.ToList();
 
             List<Channel> channelsToUpdate = await dbContext.Channels
                 .Where(c => channelIds.Contains(c.Id))
                 .ToListAsync(cancellationToken);
 
+            if (channelsToUpdate.Count != channelIds.Count)
+            {
+                var found = channelsToUpdate.Select(c => c.Id).ToHashSet();
+                int missingId = channelIds.First(id => !found.Contains(id));
+                return new NotFoundError($"Channel {missingId} does not exist.");
+            }
+
+            List<string> requestedNumbers = numberUpdates.Values.ToList();
+            bool numberConflict = await dbContext.Channels
+                .AnyAsync(
+                    c => requestedNumbers.Contains(c.Number) && !channelIds.Contains(c.Id),
+                    cancellationToken);
+            if (numberConflict)
+            {
+                return BaseError.New("Channel number must be unique");
+            }
+
             // give every channel a non-conflicting number
             foreach (var channel in channelsToUpdate)
             {
@@ -69,4 +94,32 @@ public class UpdateChannelNumbersHandler(
             return BaseError.New("Failed to update channel numbers: " + ex.Message);
         }
     }
+
+    private static Option<BaseError> ValidateRequest(UpdateChannelNumbers request)
+    {
+        if (request.Channels.Count == 0)
+        {
+            return BaseError.New("At least one channel is required");
+        }
+
+        if (request.Channels.Select(c => c.Id).Distinct().Count() != request.Channels.Count)
+        {
+            return BaseError.New("Channel ids must be unique");
+        }
+
+        if (request.Channels.Select(c => c.Number).Distinct(StringComparer.Ordinal).Count() != request.Channels.Count)
+        {
+            return BaseError.New("Channel number must be unique");
+        }
+
+        foreach (ChannelSortViewModel channel in request.Channels)
+        {
+            if (!Regex.IsMatch(channel.Number, Channel.NumberValidator))
+            {
+                return BaseError.New("Invalid channel number; two decimals are allowed for subchannels");
+            }
+        }
+
+        return Option<BaseError>.None;
+    }
 }

ErsatzTV.Application/Channels/Mapper.cs

@@ -42,10 +42,15 @@ internal static class Mapper
         new(
             channel.Id,
             channel.Number,
+            channel.SortNumber,
             channel.Name,
+            channel.Group,
+            channel.Categories,
             channel.FFmpegProfile.Name,
             channel.PreferredAudioLanguageCode,
-            GetStreamingMode(channel));
+            GetStreamingMode(channel),
+            channel.IsEnabled,
+            channel.ShowInEpg);
 
     internal static ResolutionViewModel ProjectToViewModel(Resolution resolution) =>
         new(resolution.Height, resolution.Width);

ErsatzTV.Application/Channels/Queries/GetChannelGuideData.cs

@@ -0,0 +1,10 @@
+using ErsatzTV.Core.Api.Channels;
+
+namespace ErsatzTV.Application.Channels;
+
+/// <summary>
+///     JSON channel-guide query for the EPG grid. <paramref name="Start" /> defaults to now and
+///     <paramref name="End" /> defaults to now + the configured XmltvDaysToBuild window.
+/// </summary>
+public record GetChannelGuideData(DateTimeOffset? Start, DateTimeOffset? End)
+    : IRequest<ChannelGuideResponseModel>;

ErsatzTV.Application/Channels/Queries/GetChannelGuideDataHandler.cs

@@ -0,0 +1,145 @@
+using System.Globalization;
+using ErsatzTV.Application.Configuration;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Channels;
+
+/// <summary>
+///     Builds the JSON channel guide directly from <see cref="Playout" /> items, using the shared
+///     <see cref="ChannelGuideProjector" /> guide-group/filler-merge logic (the same logic the XMLTV
+///     cache builder uses) so the two representations cannot drift. Only channels with
+///     <see cref="Channel.ShowInEpg" /> are included, mirroring <c>GetChannelGuideHandler</c>.
+///     Unlike XMLTV, filler programmes are returned (with their <see cref="Core.Domain.Filler.FillerKind" />)
+///     so the UI can decide how to render them.
+/// </summary>
+public class GetChannelGuideDataHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetChannelGuideData, ChannelGuideResponseModel>
+{
+    public async Task<ChannelGuideResponseModel> Handle(
+        GetChannelGuideData request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        int daysToBuild = await configElementRepository
+            .GetValue<int>(ConfigElementKey.XmltvDaysToBuild, cancellationToken)
+            .IfNoneAsync(2);
+
+        XmltvTimeZone xmltvTimeZone = await configElementRepository
+            .GetValue<XmltvTimeZone>(ConfigElementKey.XmltvTimeZone, cancellationToken)
+            .IfNoneAsync(XmltvTimeZone.Local);
+
+        XmltvBlockBehavior xmltvBlockBehavior = await configElementRepository
+            .GetValue<XmltvBlockBehavior>(ConfigElementKey.XmltvBlockBehavior, cancellationToken)
+            .IfNoneAsync(XmltvBlockBehavior.SplitTimeEvenly);
+
+        DateTimeOffset start = request.Start ?? DateTimeOffset.UtcNow;
+        DateTimeOffset end = request.End ?? start.AddDays(daysToBuild);
+
+        // Visible channels only (mirror GetChannelGuideHandler's ShowInEpg == false skip).
+        List<Channel> channels = await dbContext.Channels
+            .AsNoTracking()
+            .Where(c => c.ShowInEpg)
+            .Include(c => c.MirrorSourceChannel)
+            .ToListAsync(cancellationToken);
+
+        // Order channels by their decimal channel number so "2" precedes "10", matching
+        // ChannelGuide.ToXml (which orders XMLTV channels by decimal.Parse of the number).
+        channels = channels
+            .OrderBy(c => decimal.Parse(c.Number, CultureInfo.InvariantCulture))
+            .ToList();
+
+        var responseChannels = new List<ChannelGuideChannelResponseModel>();
+
+        foreach (Channel channel in channels)
+        {
+            bool isMirror = channel.PlayoutSource == ChannelPlayoutSource.Mirror
+                && channel.MirrorSourceChannel is not null;
+
+            string sourceChannelNumber = isMirror ? channel.MirrorSourceChannel.Number : channel.Number;
+            TimeSpan playoutOffset = isMirror ? channel.PlayoutOffset ?? TimeSpan.Zero : TimeSpan.Zero;
+
+            List<Playout> playouts = await dbContext.Playouts
+                .AsNoTracking()
+                .Filter(p => p.Channel.Number == sourceChannelNumber)
+                .IncludeGuideMetadata()
+                .AsSplitQuery()
+                .ToListAsync(cancellationToken);
+
+            var programmes = new List<ChannelGuideProgrammeResponseModel>();
+
+            foreach (Playout playout in playouts)
+            {
+                // ExternalJson playouts materialize items from a file rather than Playout.Items; they are
+                // out of scope for the JSON guide (see issue #102 notes).
+                if (playout.ScheduleKind is PlayoutScheduleKind.ExternalJson)
+                {
+                    continue;
+                }
+
+                // Filter to the window (on the pre-offset time, mirroring the XMLTV builder) then apply the
+                // mirror playout offset without mutating the loaded (shared, AsNoTracking) entities.
+                List<PlayoutItem> sorted = playout.Items
+                    .OrderBy(pi => pi.Start)
+                    .Filter(pi => pi.StartOffset <= end)
+                    .Select(pi => playoutOffset == TimeSpan.Zero ? pi : WithPlayoutOffset(pi, playoutOffset))
+                    .ToList();
+
+                foreach (ChannelGuideEntry entry in ChannelGuideProjector.Project(
+                             playout.ScheduleKind,
+                             sorted,
+                             xmltvTimeZone,
+                             xmltvBlockBehavior))
+                {
+                    // drop programmes that finish before the requested window starts
+                    if (entry.Stop <= start)
+                    {
+                        continue;
+                    }
+
+                    string subtitle = ChannelGuideMetadata.GetSubtitle(entry.DisplayItem);
+
+                    programmes.Add(
+                        new ChannelGuideProgrammeResponseModel(
+                            entry.Start,
+                            entry.Stop,
+                            ChannelGuideMetadata.GetTitle(entry.DisplayItem),
+                            string.IsNullOrWhiteSpace(subtitle) ? null : subtitle,
+                            ChannelGuideMetadata.GetCategory(entry.DisplayItem),
+                            entry.DisplayItem.FillerKind));
+                }
+            }
+
+            responseChannels.Add(
+                new ChannelGuideChannelResponseModel(
+                    channel.Number,
+                    channel.Name,
+                    programmes.OrderBy(p => p.Start).ToList()));
+        }
+
+        return new ChannelGuideResponseModel(start, end, responseChannels);
+    }
+
+    // Copy (don't mutate) the loaded PlayoutItem when shifting by the mirror playout offset. The loaded
+    // entities are AsNoTracking and shared; mutating them in place would corrupt the guide projection.
+    // Mirrors the XMLTV builder, which shifts only Start/Finish (not the Guide* window).
+    private static PlayoutItem WithPlayoutOffset(PlayoutItem item, TimeSpan offset) =>
+        new()
+        {
+            MediaItem = item.MediaItem,
+            Start = item.Start + offset,
+            Finish = item.Finish + offset,
+            GuideStart = item.GuideStart,
+            GuideFinish = item.GuideFinish,
+            GuideGroup = item.GuideGroup,
+            FillerKind = item.FillerKind,
+            CustomTitle = item.CustomTitle
+        };
+}

ErsatzTV.Application/Channels/Queries/GetChannelStatesForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Channels;
+
+namespace ErsatzTV.Application.Channels;
+
+public record GetChannelStatesForApi(DateTime Now) : IRequest<List<ChannelStateResponseModel>>;

ErsatzTV.Application/Channels/Queries/GetChannelStatesForApiHandler.cs

@@ -0,0 +1,151 @@
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using PlayoutMapper = ErsatzTV.Application.Playouts.Mapper;
+
+namespace ErsatzTV.Application.Channels;
+
+public class GetChannelStatesForApiHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IFFmpegSegmenterService ffmpegSegmenterService)
+    : IRequestHandler<GetChannelStatesForApi, List<ChannelStateResponseModel>>
+{
+    // a guide entry (program + surrounding filler) never spans anywhere near a day; the time
+    // bound also protects against GuideGroup values recycling (mod 10000) elsewhere in a playout
+    private static readonly TimeSpan GuideEntryBound = TimeSpan.FromDays(1);
+
+    public async Task<List<ChannelStateResponseModel>> Handle(
+        GetChannelStatesForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        List<Channel> channels = await dbContext.Channels
+            .AsNoTracking()
+            .OrderBy(c => c.SortNumber)
+            .ThenBy(c => c.Number)
+            .ToListAsync(cancellationToken);
+
+        if (channels.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, (int SourceChannelId, TimeSpan Offset, DateTime LookupTime)> channelLookup = channels
+            .ToDictionary(
+                c => c.Id,
+                c =>
+                {
+                    TimeSpan offset = c.PlayoutOffset ?? TimeSpan.Zero;
+                    return (c.MirrorSourceChannelId ?? c.Id, offset, request.Now - offset);
+                });
+
+        // one covering-item query per distinct lookup time (i.e. per distinct playout offset,
+        // typically just one) with a cheap projection; metadata is hydrated in a second query
+        // for only the covering items' guide groups
+        var coveringBySourceAndTime = new Dictionary<(int SourceChannelId, DateTime LookupTime), CoveringItem>();
+        foreach (IGrouping<DateTime, (int SourceChannelId, TimeSpan Offset, DateTime LookupTime)> timeGroup in
+                 channelLookup.Values.GroupBy(v => v.LookupTime))
+        {
+            DateTime lookupTime = timeGroup.Key;
+            int[] sourceChannelIds = timeGroup.Map(v => v.SourceChannelId).Distinct().ToArray();
+
+            List<CoveringItem> covering = await dbContext.PlayoutItems
+                .AsNoTracking()
+                .Where(pi => sourceChannelIds.Contains(pi.Playout.ChannelId))
+                .Where(pi => pi.Start <= lookupTime && pi.Finish > lookupTime)
+                .Select(pi => new CoveringItem(pi.Id, pi.PlayoutId, pi.Playout.ChannelId, pi.GuideGroup, pi.Start))
+                .ToListAsync(cancellationToken);
+
+            foreach (CoveringItem item in covering.OrderBy(ci => ci.Start))
+            {
+                coveringBySourceAndTime.TryAdd((item.ChannelId, lookupTime), item);
+            }
+        }
+
+        Dictionary<(int PlayoutId, int GuideGroup), List<PlayoutItem>> itemsByGuideEntry = [];
+        if (coveringBySourceAndTime.Count > 0)
+        {
+            int[] playoutIds = coveringBySourceAndTime.Values.Map(ci => ci.PlayoutId).Distinct().ToArray();
+            int[] guideGroups = coveringBySourceAndTime.Values.Map(ci => ci.GuideGroup).Distinct().ToArray();
+            DateTime windowStart = channelLookup.Values.Min(v => v.LookupTime) - GuideEntryBound;
+            DateTime windowFinish = channelLookup.Values.Max(v => v.LookupTime) + GuideEntryBound;
+
+            List<PlayoutItem> guideEntryItems = await dbContext.PlayoutItems
+                .AsNoTracking()
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as Episode).EpisodeMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as Episode).Season)
+                .ThenInclude(s => s.Show)
+                .ThenInclude(s => s.ShowMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as Movie).MovieMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as MusicVideo).MusicVideoMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as MusicVideo).Artist)
+                .ThenInclude(a => a.ArtistMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as OtherVideo).OtherVideoMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as Song).SongMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as Image).ImageMetadata)
+                .Include(pi => pi.MediaItem)
+                .ThenInclude(mi => (mi as RemoteStream).RemoteStreamMetadata)
+                .Where(pi => playoutIds.Contains(pi.PlayoutId) && guideGroups.Contains(pi.GuideGroup))
+                .Where(pi => pi.Start <= windowFinish && pi.Finish > windowStart)
+                .ToListAsync(cancellationToken);
+
+            itemsByGuideEntry = guideEntryItems
+                .GroupBy(pi => (pi.PlayoutId, pi.GuideGroup))
+                .ToDictionary(g => g.Key, g => g.OrderBy(pi => pi.Start).ToList());
+        }
+
+        return channels
+            .Map(channel =>
+            {
+                (int sourceChannelId, TimeSpan offset, DateTime lookupTime) = channelLookup[channel.Id];
+                ChannelNowPlayingResponseModel nowPlaying = null;
+
+                if (coveringBySourceAndTime.TryGetValue((sourceChannelId, lookupTime), out CoveringItem covering) &&
+                    itemsByGuideEntry.TryGetValue(
+                        (covering.PlayoutId, covering.GuideGroup),
+                        out List<PlayoutItem> guideEntry))
+                {
+                    // like the XMLTV guide, surface the program rather than its filler: use the
+                    // covering item itself when it is a program part, otherwise the guide entry's
+                    // first program item; an entry with no program item (e.g. offline fallback
+                    // filler) stays null
+                    PlayoutItem coveringItem = guideEntry.Find(pi => pi.Id == covering.Id);
+                    PlayoutItem displayItem = coveringItem?.FillerKind == FillerKind.None
+                        ? coveringItem
+                        : guideEntry.Find(pi => pi.FillerKind == FillerKind.None);
+
+                    if (displayItem is not null)
+                    {
+                        DateTime start = guideEntry[0].Start;
+                        DateTime finish = displayItem.GuideFinish ?? guideEntry.Max(pi => pi.Finish);
+
+                        nowPlaying = new ChannelNowPlayingResponseModel(
+                            PlayoutMapper.GetDisplayTitle(displayItem.MediaItem, Optional(displayItem.ChapterTitle)),
+                            new DateTimeOffset(start + offset, TimeSpan.Zero),
+                            new DateTimeOffset(finish + offset, TimeSpan.Zero));
+                    }
+                }
+
+                return new ChannelStateResponseModel(
+                    channel.Id,
+                    channel.Number,
+                    ffmpegSegmenterService.IsActive(channel.Number),
+                    nowPlaying);
+            })
+            .ToList();
+    }
+
+    private sealed record CoveringItem(int Id, int PlayoutId, int ChannelId, int GuideGroup, DateTime Start);
+}

ErsatzTV.Application/FFmpegProfiles/Mapper.cs

@@ -52,13 +52,17 @@ internal static class Mapper
             ffmpegProfile.Id,
             ffmpegProfile.Name,
             ffmpegProfile.ThreadCount,
+            ffmpegProfile.NormalizeAudio,
+            ffmpegProfile.NormalizeVideo,
             ffmpegProfile.HardwareAcceleration,
             ffmpegProfile.VaapiDisplay,
             ffmpegProfile.VaapiDriver,
             ffmpegProfile.VaapiDevice,
             ffmpegProfile.QsvExtraHardwareFrames,
+            ffmpegProfile.ResolutionId,
             ffmpegProfile.Resolution.Name,
             ffmpegProfile.ScalingBehavior,
+            ffmpegProfile.PadMode,
             ffmpegProfile.VideoFormat,
             ffmpegProfile.VideoProfile,
             ffmpegProfile.VideoPreset,
@@ -71,8 +75,10 @@ internal static class Mapper
             ffmpegProfile.AudioBitrate,
             ffmpegProfile.AudioBufferSize,
             ffmpegProfile.NormalizeLoudnessMode,
+            ffmpegProfile.TargetLoudness,
             ffmpegProfile.AudioChannels,
             ffmpegProfile.AudioSampleRate,
             ffmpegProfile.NormalizeFramerate,
-            ffmpegProfile.DeinterlaceVideo);
+            ffmpegProfile.NormalizeColors,
+            ffmpegProfile.DeinterlaceVideo == true);
 }

ErsatzTV.Application/Filler/Commands/CreateFillerPreset.cs

@@ -20,4 +20,6 @@ public record CreateFillerPreset(
     int? PlaylistId,
     string Expression,
     bool UseChaptersAsMediaItems
-) : IRequest<Either<BaseError, Unit>>;
+) : IRequest<Either<BaseError, CreateFillerPresetResult>>;
+
+public record CreateFillerPresetResult(int FillerPresetId) : EntityIdResult(FillerPresetId);

ErsatzTV.Application/Filler/Commands/CreateFillerPresetHandler.cs

@@ -6,23 +6,25 @@ using Microsoft.EntityFrameworkCore;
 namespace ErsatzTV.Application.Filler;
 
 public class CreateFillerPresetHandler(IDbContextFactory<TvContext> dbContextFactory)
-    : IRequestHandler<CreateFillerPreset, Either<BaseError, Unit>>
+    : IRequestHandler<CreateFillerPreset, Either<BaseError, CreateFillerPresetResult>>
 {
-    public async Task<Either<BaseError, Unit>> Handle(CreateFillerPreset request, CancellationToken cancellationToken)
+    public async Task<Either<BaseError, CreateFillerPresetResult>> Handle(
+        CreateFillerPreset request,
+        CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
         Validation<BaseError, FillerPreset> validation = await Validate(dbContext, request);
         return await validation.Apply(fp => Persist(dbContext, fp, cancellationToken));
     }
 
-    private static async Task<Unit> Persist(
+    private static async Task<CreateFillerPresetResult> Persist(
         TvContext dbContext,
         FillerPreset fillerPreset,
         CancellationToken cancellationToken)
     {
         await dbContext.FillerPresets.AddAsync(fillerPreset, cancellationToken);
         await dbContext.SaveChangesAsync(cancellationToken);
-        return Unit.Default;
+        return new CreateFillerPresetResult(fillerPreset.Id);
     }
 
     private static Task<Validation<BaseError, FillerPreset>> Validate(

ErsatzTV.Application/Filler/Commands/DeleteFillerPresetHandler.cs

@@ -1,5 +1,6 @@
-using ErsatzTV.Core;
+using ErsatzTV.Core;
 using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
 using Microsoft.EntityFrameworkCore;
@@ -18,8 +19,14 @@ public class DeleteFillerPresetHandler : IRequestHandler<DeleteFillerPreset, Eit
         CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-        Validation<BaseError, FillerPreset> validation = await FillerPresetMustExist(dbContext, request, cancellationToken);
-        return await validation.Apply(ps => DoDeletion(dbContext, ps));
+        Option<FillerPreset> maybeFillerPreset = await FillerPresetMustExist(dbContext, request, cancellationToken);
+
+        // must-exist maps to a NotFoundError Either directly (not via Validation, which
+        // aggregates errors and loses the subtype the API layer maps to 404)
+        return await maybeFillerPreset.Match(
+            Some: fillerPreset => DoDeletion(dbContext, fillerPreset).Map(Right<BaseError, Unit>),
+            None: () => Task.FromResult<Either<BaseError, Unit>>(
+                new NotFoundError($"FillerPreset {request.FillerPresetId} does not exist.")));
     }
 
     private static Task<Unit> DoDeletion(TvContext dbContext, FillerPreset fillerPreset)
@@ -28,11 +35,10 @@ public class DeleteFillerPresetHandler : IRequestHandler<DeleteFillerPreset, Eit
         return dbContext.SaveChangesAsync().ToUnit();
     }
 
-    private static Task<Validation<BaseError, FillerPreset>> FillerPresetMustExist(
+    private static Task<Option<FillerPreset>> FillerPresetMustExist(
         TvContext dbContext,
         DeleteFillerPreset request,
         CancellationToken cancellationToken) =>
         dbContext.FillerPresets
-            .SelectOneAsync(fp => fp.Id, ps => ps.Id == request.FillerPresetId, cancellationToken)
-            .Map(o => o.ToValidation<BaseError>($"FillerPreset {request.FillerPresetId} does not exist."));
+            .SelectOneAsync(fp => fp.Id, ps => ps.Id == request.FillerPresetId, cancellationToken);
 }

ErsatzTV.Application/Filler/Commands/UpdateFillerPresetHandler.cs

@@ -1,5 +1,6 @@
-using ErsatzTV.Core;
+using ErsatzTV.Core;
 using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
 using Microsoft.EntityFrameworkCore;
@@ -12,8 +13,19 @@ public class UpdateFillerPresetHandler(IDbContextFactory<TvContext> dbContextFac
     public async Task<Either<BaseError, Unit>> Handle(UpdateFillerPreset request, CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
-        Validation<BaseError, FillerPreset> validation = await Validate(dbContext, request, cancellationToken);
-        return await validation.Apply(ps => ApplyUpdateRequest(dbContext, ps, request, cancellationToken));
+        Option<FillerPreset> maybeFillerPreset = await FillerPresetMustExist(dbContext, request, cancellationToken);
+
+        // must-exist maps to a NotFoundError Either directly (not via Validation, which
+        // aggregates errors and loses the subtype the API layer maps to 404)
+        return await maybeFillerPreset.Match(
+            Some: async fillerPreset =>
+            {
+                Validation<BaseError, string> validation = await ValidateName(dbContext, request);
+                return await validation.Apply((string _) =>
+                    ApplyUpdateRequest(dbContext, fillerPreset, request, cancellationToken));
+            },
+            None: () => Task.FromResult<Either<BaseError, Unit>>(
+                new NotFoundError($"FillerPreset {request.Id} does not exist.")));
     }
 
     private static async Task<Unit> ApplyUpdateRequest(
@@ -44,20 +56,12 @@ public class UpdateFillerPresetHandler(IDbContextFactory<TvContext> dbContextFac
         return Unit.Default;
     }
 
-    private static async Task<Validation<BaseError, FillerPreset>> Validate(
-        TvContext dbContext,
-        UpdateFillerPreset request,
-        CancellationToken cancellationToken) =>
-        (await FillerPresetMustExist(dbContext, request, cancellationToken), await ValidateName(dbContext, request))
-        .Apply((collectionToUpdate, _) => collectionToUpdate);
-
-    private static Task<Validation<BaseError, FillerPreset>> FillerPresetMustExist(
+    private static Task<Option<FillerPreset>> FillerPresetMustExist(
         TvContext dbContext,
         UpdateFillerPreset request,
         CancellationToken cancellationToken) =>
         dbContext.FillerPresets
-            .SelectOneAsync(ps => ps.Id, ps => ps.Id == request.Id, cancellationToken)
-            .Map(o => o.ToValidation<BaseError>("Filler preset does not exist"));
+            .SelectOneAsync(ps => ps.Id, ps => ps.Id == request.Id, cancellationToken);
 
     private static async Task<Validation<BaseError, string>> ValidateName(
         TvContext dbContext,

ErsatzTV.Application/Filler/Mapper.cs

@@ -1,9 +1,32 @@
-using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Api.Filler;
+using ErsatzTV.Core.Domain.Filler;
 
 namespace ErsatzTV.Application.Filler;
 
 internal static class Mapper
 {
+    internal static FillerPresetResponseModel ProjectToResponseModel(FillerPreset fillerPreset) =>
+        new(fillerPreset.Id, fillerPreset.Name);
+
+    internal static FillerPresetFullResponseModel ProjectToFullResponseModel(FillerPreset fillerPreset) =>
+        new(
+            fillerPreset.Id,
+            fillerPreset.Name,
+            fillerPreset.FillerKind,
+            fillerPreset.FillerMode,
+            fillerPreset.Duration,
+            fillerPreset.Count,
+            fillerPreset.PadToNearestMinute,
+            fillerPreset.AllowWatermarks,
+            fillerPreset.CollectionType,
+            fillerPreset.CollectionId,
+            fillerPreset.MediaItemId,
+            fillerPreset.MultiCollectionId,
+            fillerPreset.SmartCollectionId,
+            fillerPreset.PlaylistId,
+            fillerPreset.Expression,
+            fillerPreset.UseChaptersAsMediaItems);
+
     internal static FillerPresetViewModel ProjectToViewModel(FillerPreset fillerPreset) =>
         new(
             fillerPreset.Id,

ErsatzTV.Application/Filler/Queries/GetAllFillerPresetsForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Filler;
+
+namespace ErsatzTV.Application.Filler;
+
+public record GetAllFillerPresetsForApi : IRequest<List<FillerPresetResponseModel>>;

ErsatzTV.Application/Filler/Queries/GetAllFillerPresetsForApiHandler.cs

@@ -0,0 +1,22 @@
+using ErsatzTV.Core.Api.Filler;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Filler.Mapper;
+
+namespace ErsatzTV.Application.Filler;
+
+public class GetAllFillerPresetsForApiHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetAllFillerPresetsForApi, List<FillerPresetResponseModel>>
+{
+    public async Task<List<FillerPresetResponseModel>> Handle(
+        GetAllFillerPresetsForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        List<FillerPreset> fillerPresets = await dbContext.FillerPresets
+            .AsNoTracking()
+            .ToListAsync(cancellationToken);
+        return fillerPresets.Map(ProjectToResponseModel).ToList();
+    }
+}

ErsatzTV.Application/Filler/Queries/GetFillerPresetByIdForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Filler;
+
+namespace ErsatzTV.Application.Filler;
+
+public record GetFillerPresetByIdForApi(int Id) : IRequest<Option<FillerPresetFullResponseModel>>;

ErsatzTV.Application/Filler/Queries/GetFillerPresetByIdForApiHandler.cs

@@ -0,0 +1,22 @@
+using ErsatzTV.Core.Api.Filler;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Filler.Mapper;
+
+namespace ErsatzTV.Application.Filler;
+
+public class GetFillerPresetByIdForApiHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetFillerPresetByIdForApi, Option<FillerPresetFullResponseModel>>
+{
+    public async Task<Option<FillerPresetFullResponseModel>> Handle(
+        GetFillerPresetByIdForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        return await dbContext.FillerPresets
+            .AsNoTracking()
+            .SelectOneAsync(fp => fp.Id, fp => fp.Id == request.Id, cancellationToken)
+            .MapT(ProjectToFullResponseModel);
+    }
+}

ErsatzTV.Application/Graphics/Queries/GetAllGraphicsElementsForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Graphics;
+
+namespace ErsatzTV.Application.Graphics;
+
+public record GetAllGraphicsElementsForApi : IRequest<List<GraphicsElementResponseModel>>;

ErsatzTV.Application/Graphics/Queries/GetAllGraphicsElementsForApiHandler.cs

@@ -0,0 +1,27 @@
+using ErsatzTV.Core.Api.Graphics;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Graphics.Mapper;
+
+namespace ErsatzTV.Application.Graphics;
+
+public class GetAllGraphicsElementsForApiHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetAllGraphicsElementsForApi, List<GraphicsElementResponseModel>>
+{
+    public async Task<List<GraphicsElementResponseModel>> Handle(
+        GetAllGraphicsElementsForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        List<GraphicsElement> graphicsElements = await dbContext.GraphicsElements
+            .AsNoTracking()
+            .ToListAsync(cancellationToken);
+        return graphicsElements
+            .Map(ProjectToViewModel)
+            .OrderBy(e => e.Name == e.FileName)
+            .ThenBy(e => e.Name)
+            .Select(vm => new GraphicsElementResponseModel(vm.Id, vm.Name))
+            .ToList();
+    }
+}

ErsatzTV.Application/Health/Mapper.cs

@@ -0,0 +1,24 @@
+using ErsatzTV.Core.Api.Health;
+using ErsatzTV.Core.Health;
+
+namespace ErsatzTV.Application.Health;
+
+internal static class Mapper
+{
+    internal static HealthCheckResponseModel ProjectToResponseModel(HealthCheckResult result) =>
+        new(
+            result.Title,
+            GetStatus(result.Status),
+            result.Message,
+            result.Link.MatchUnsafe(l => l.Link, () => null));
+
+    private static string GetStatus(HealthCheckStatus status) =>
+        status switch
+        {
+            HealthCheckStatus.Pass => "pass",
+            HealthCheckStatus.Fail => "fail",
+            HealthCheckStatus.Warning => "warn",
+            HealthCheckStatus.Info => "info",
+            _ => throw new ArgumentOutOfRangeException(nameof(status), status, null)
+        };
+}

ErsatzTV.Application/Health/Queries/GetAllHealthCheckResultsForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Health;
+
+namespace ErsatzTV.Application.Health;
+
+public record GetAllHealthCheckResultsForApi : IRequest<List<HealthCheckResponseModel>>;

ErsatzTV.Application/Health/Queries/GetAllHealthCheckResultsForApiHandler.cs

@@ -0,0 +1,32 @@
+using ErsatzTV.Core.Api.Health;
+using ErsatzTV.Core.Health;
+using static ErsatzTV.Application.Health.Mapper;
+
+namespace ErsatzTV.Application.Health;
+
+public class GetAllHealthCheckResultsForApiHandler
+    : IRequestHandler<GetAllHealthCheckResultsForApi, List<HealthCheckResponseModel>>
+{
+    private readonly IHealthCheckService _healthCheckService;
+
+    public GetAllHealthCheckResultsForApiHandler(IHealthCheckService healthCheckService) =>
+        _healthCheckService = healthCheckService;
+
+    public async Task<List<HealthCheckResponseModel>> Handle(
+        GetAllHealthCheckResultsForApi request,
+        CancellationToken cancellationToken)
+    {
+        try
+        {
+            List<HealthCheckResult> results = await _healthCheckService.PerformHealthChecks(cancellationToken);
+            return results
+                .Filter(r => r.Status != HealthCheckStatus.NotApplicable)
+                .Map(ProjectToResponseModel)
+                .ToList();
+        }
+        catch (Exception ex) when (ex is TaskCanceledException or OperationCanceledException)
+        {
+            return [];
+        }
+    }
+}

ErsatzTV.Application/Images/Queries/ImageFolderExists.cs

@@ -0,0 +1,3 @@
+namespace ErsatzTV.Application.Images;
+
+public record ImageFolderExists(int LibraryFolderId) : IRequest<bool>;

ErsatzTV.Application/Images/Queries/ImageFolderExistsHandler.cs

@@ -0,0 +1,21 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Images;
+
+public class ImageFolderExistsHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<ImageFolderExists, bool>
+{
+    public async Task<bool> Handle(ImageFolderExists request, CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        return await dbContext.LibraryFolders
+            .AsNoTracking()
+            .AnyAsync(
+                lf => lf.Id == request.LibraryFolderId
+                      && lf.LibraryPath.Library.MediaKind == LibraryMediaKind.Images,
+                cancellationToken);
+    }
+}

ErsatzTV.Application/Libraries/Queries/GetLibraryScanStatus.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Libraries;
+
+namespace ErsatzTV.Application.Libraries;
+
+public record GetLibraryScanStatus : IRequest<List<LibraryScanStatusResponseModel>>;

ErsatzTV.Application/Libraries/Queries/GetLibraryScanStatusHandler.cs

@@ -0,0 +1,20 @@
+using ErsatzTV.Core.Api.Libraries;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.Core.Metadata;
+
+namespace ErsatzTV.Application.Libraries;
+
+public class GetLibraryScanStatusHandler(IScannerProxyService scannerProxyService)
+    : IRequestHandler<GetLibraryScanStatus, List<LibraryScanStatusResponseModel>>
+{
+    public Task<List<LibraryScanStatusResponseModel>> Handle(
+        GetLibraryScanStatus request,
+        CancellationToken cancellationToken)
+    {
+        List<LibraryScanStatusResponseModel> result = scannerProxyService.GetActiveScans()
+            .Select(scan => new LibraryScanStatusResponseModel(scan.LibraryId, scan.Progress))
+            .ToList();
+
+        return Task.FromResult(result);
+    }
+}

ErsatzTV.Application/LibraryBrowse/LibraryBrowseItemMapper.cs

@@ -0,0 +1,620 @@
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Emby;
+using ErsatzTV.Core.Jellyfin;
+using ErsatzTV.Infrastructure.Data;
+using Flurl;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.LibraryBrowse;
+
+// Shared MediaItem -> LibraryBrowseItemResponseModel projection used by both the library-browse
+// search handler and the collection-items handler (#155). Keeping the per-kind hydration and the
+// rooted-artwork logic in one place avoids duplicating the Blazor-vs-SPA artwork rooting rules
+// (see the Artwork helper below and docs/api-conventions.md §4).
+internal static class LibraryBrowseItemMapper
+{
+    // Hydrates an arbitrary set of media item ids (any kinds mixed) into response models. MediaItem
+    // ids are globally unique across kinds, so passing the full id list to every per-kind query is
+    // safe: each query only matches its own kind. Callers order/page the result themselves.
+    public static async Task<List<LibraryBrowseItemResponseModel>> HydrateMediaItemsByIds(
+        TvContext dbContext,
+        IReadOnlyList<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        var idList = ids.Distinct().ToList();
+
+        var results = new List<LibraryBrowseItemResponseModel>();
+        results.AddRange(await GetMovies(dbContext, idList, cancellationToken));
+        results.AddRange(await GetShows(dbContext, idList, cancellationToken));
+        results.AddRange(await GetSeasons(dbContext, idList, cancellationToken));
+        results.AddRange(await GetArtists(dbContext, idList, cancellationToken));
+        results.AddRange(await GetEpisodes(dbContext, idList, cancellationToken));
+        results.AddRange(await GetMusicVideos(dbContext, idList, cancellationToken));
+        results.AddRange(await GetSongs(dbContext, idList, cancellationToken));
+        results.AddRange(await GetOtherVideos(dbContext, idList, cancellationToken));
+        results.AddRange(await GetImages(dbContext, idList, cancellationToken));
+        results.AddRange(await GetRemoteStreams(dbContext, idList, cancellationToken));
+        return results;
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetMovies(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.MovieMetadata
+            .AsNoTracking()
+            .Where(mm => ids.Contains(mm.MovieId))
+            .Include(mm => mm.Artwork)
+            .Include(mm => mm.Movie)
+            .ThenInclude(m => m.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(mm => mm.Movie)
+            .ThenInclude(m => m.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(mm => mm.MovieId)
+                .Select(g => g.OrderBy(mm => mm.Id).First())
+                .Map(mm => new LibraryBrowseItemResponseModel(
+                mm.MovieId,
+                LibraryBrowseMediaType.Movie,
+                mm.Title ?? string.Empty,
+                mm.Movie.LibraryPath.LibraryId,
+                mm.Movie.LibraryPath.Library.Name,
+                Artwork(mm, ArtworkKind.Poster),
+                BestDuration(mm.Movie.MediaVersions),
+                1,
+                null,
+                CollectionType.Movie,
+                null,
+                null,
+                null,
+                null,
+                mm.MovieId,
+                null)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetShows(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.Episodes
+            .AsNoTracking()
+            .Where(e => ids.Contains(e.Season.ShowId))
+            .GroupBy(e => e.Season.ShowId)
+            .Select(g => new { ShowId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.ShowId, g => g.Count, cancellationToken);
+
+        return await dbContext.ShowMetadata
+            .AsNoTracking()
+            .Where(sm => ids.Contains(sm.ShowId))
+            .Include(sm => sm.Artwork)
+            .Include(sm => sm.Show)
+            .ThenInclude(s => s.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(sm => sm.ShowId)
+                .Select(g => g.OrderBy(sm => sm.Id).First())
+                .Map(sm => new LibraryBrowseItemResponseModel(
+                sm.ShowId,
+                LibraryBrowseMediaType.TelevisionShow,
+                sm.Title ?? string.Empty,
+                sm.Show.LibraryPath.LibraryId,
+                sm.Show.LibraryPath.Library.Name,
+                Artwork(sm, ArtworkKind.Poster),
+                null,
+                counts.TryGetValue(sm.ShowId, out int count) ? count : 0,
+                null,
+                CollectionType.TelevisionShow,
+                null,
+                null,
+                null,
+                null,
+                sm.ShowId,
+                null)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetSeasons(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.Episodes
+            .AsNoTracking()
+            .Where(e => ids.Contains(e.SeasonId))
+            .GroupBy(e => e.SeasonId)
+            .Select(g => new { SeasonId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.SeasonId, g => g.Count, cancellationToken);
+
+        return await dbContext.SeasonMetadata
+            .AsNoTracking()
+            .Where(sm => ids.Contains(sm.SeasonId))
+            .Include(sm => sm.Artwork)
+            .Include(sm => sm.Season)
+            .ThenInclude(s => s.Show)
+            .ThenInclude(s => s.ShowMetadata)
+            .ThenInclude(shm => shm.Artwork)
+            .Include(sm => sm.Season)
+            .ThenInclude(s => s.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(sm => sm.SeasonId)
+                .Select(g => g.OrderBy(sm => sm.Id).First())
+                .Map(sm => new LibraryBrowseItemResponseModel(
+                sm.SeasonId,
+                LibraryBrowseMediaType.TelevisionSeason,
+                SeasonTitle(sm),
+                sm.Season.LibraryPath.LibraryId,
+                sm.Season.LibraryPath.Library.Name,
+                SeasonArtwork(sm),
+                null,
+                counts.TryGetValue(sm.SeasonId, out int count) ? count : 0,
+                null,
+                CollectionType.TelevisionSeason,
+                null,
+                null,
+                null,
+                null,
+                sm.SeasonId,
+                null)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetArtists(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.MusicVideos
+            .AsNoTracking()
+            .Where(mv => ids.Contains(mv.ArtistId))
+            .GroupBy(mv => mv.ArtistId)
+            .Select(g => new { ArtistId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.ArtistId, g => g.Count, cancellationToken);
+
+        return await dbContext.ArtistMetadata
+            .AsNoTracking()
+            .Where(am => ids.Contains(am.ArtistId))
+            .Include(am => am.Artwork)
+            .Include(am => am.Artist)
+            .ThenInclude(a => a.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(am => am.ArtistId)
+                .Select(g => g.OrderBy(am => am.Id).First())
+                .Map(am => new LibraryBrowseItemResponseModel(
+                am.ArtistId,
+                LibraryBrowseMediaType.Artist,
+                am.Title ?? string.Empty,
+                am.Artist.LibraryPath.LibraryId,
+                am.Artist.LibraryPath.Library.Name,
+                Artwork(am, ArtworkKind.Thumbnail),
+                null,
+                counts.TryGetValue(am.ArtistId, out int count) ? count : 0,
+                null,
+                CollectionType.Artist,
+                null,
+                null,
+                null,
+                null,
+                am.ArtistId,
+                null)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetEpisodes(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.EpisodeMetadata
+            .AsNoTracking()
+            .Where(em => ids.Contains(em.EpisodeId))
+            .Include(em => em.Artwork)
+            .Include(em => em.Episode)
+            .ThenInclude(e => e.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(em => em.Episode)
+            .ThenInclude(e => e.MediaVersions)
+            .Include(em => em.Episode)
+            .ThenInclude(e => e.Season)
+            .ThenInclude(s => s.Show)
+            .ThenInclude(sh => sh.ShowMetadata)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(em => em.EpisodeId)
+                .Select(g => g.OrderBy(em => em.Id).First())
+                .Map(em => new LibraryBrowseItemResponseModel(
+                    em.EpisodeId,
+                    LibraryBrowseMediaType.Episode,
+                    em.Title ?? string.Empty,
+                    em.Episode.LibraryPath.LibraryId,
+                    em.Episode.LibraryPath.Library.Name,
+                    ArtworkWithFallback(em, ArtworkKind.Thumbnail, ArtworkKind.Poster),
+                    BestDuration(em.Episode.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.Episode,
+                    null,
+                    null,
+                    null,
+                    null,
+                    em.EpisodeId,
+                    null,
+                    EpisodeSubtitle(em))).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetMusicVideos(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.MusicVideoMetadata
+            .AsNoTracking()
+            .Where(mvm => ids.Contains(mvm.MusicVideoId))
+            .Include(mvm => mvm.Artwork)
+            .Include(mvm => mvm.MusicVideo)
+            .ThenInclude(mv => mv.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(mvm => mvm.MusicVideo)
+            .ThenInclude(mv => mv.MediaVersions)
+            .Include(mvm => mvm.MusicVideo)
+            .ThenInclude(mv => mv.Artist)
+            .ThenInclude(a => a.ArtistMetadata)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(mvm => mvm.MusicVideoId)
+                .Select(g => g.OrderBy(mvm => mvm.Id).First())
+                .Map(mvm => new LibraryBrowseItemResponseModel(
+                    mvm.MusicVideoId,
+                    LibraryBrowseMediaType.MusicVideo,
+                    mvm.Title ?? string.Empty,
+                    mvm.MusicVideo.LibraryPath.LibraryId,
+                    mvm.MusicVideo.LibraryPath.Library.Name,
+                    ArtworkWithFallback(mvm, ArtworkKind.Thumbnail, ArtworkKind.Poster),
+                    BestDuration(mvm.MusicVideo.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.MusicVideo,
+                    null,
+                    null,
+                    null,
+                    null,
+                    mvm.MusicVideoId,
+                    null,
+                    MusicVideoSubtitle(mvm))).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetSongs(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.SongMetadata
+            .AsNoTracking()
+            .Where(sm => ids.Contains(sm.SongId))
+            .Include(sm => sm.Artwork)
+            .Include(sm => sm.Song)
+            .ThenInclude(s => s.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(sm => sm.Song)
+            .ThenInclude(s => s.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(sm => sm.SongId)
+                .Select(g => g.OrderBy(sm => sm.Id).First())
+                .Map(sm => new LibraryBrowseItemResponseModel(
+                    sm.SongId,
+                    LibraryBrowseMediaType.Song,
+                    sm.Title ?? string.Empty,
+                    sm.Song.LibraryPath.LibraryId,
+                    sm.Song.LibraryPath.Library.Name,
+                    ArtworkWithFallback(sm, ArtworkKind.Thumbnail, ArtworkKind.Poster),
+                    BestDuration(sm.Song.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.Song,
+                    null,
+                    null,
+                    null,
+                    null,
+                    sm.SongId,
+                    null,
+                    SongSubtitle(sm))).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetOtherVideos(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.OtherVideoMetadata
+            .AsNoTracking()
+            .Where(ovm => ids.Contains(ovm.OtherVideoId))
+            .Include(ovm => ovm.Artwork)
+            .Include(ovm => ovm.OtherVideo)
+            .ThenInclude(ov => ov.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(ovm => ovm.OtherVideo)
+            .ThenInclude(ov => ov.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(ovm => ovm.OtherVideoId)
+                .Select(g => g.OrderBy(ovm => ovm.Id).First())
+                .Map(ovm => new LibraryBrowseItemResponseModel(
+                    ovm.OtherVideoId,
+                    LibraryBrowseMediaType.OtherVideo,
+                    ovm.Title ?? string.Empty,
+                    ovm.OtherVideo.LibraryPath.LibraryId,
+                    ovm.OtherVideo.LibraryPath.Library.Name,
+                    ArtworkWithFallback(ovm, ArtworkKind.Thumbnail, ArtworkKind.Poster),
+                    BestDuration(ovm.OtherVideo.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.OtherVideo,
+                    null,
+                    null,
+                    null,
+                    null,
+                    ovm.OtherVideoId,
+                    null,
+                    string.IsNullOrWhiteSpace(ovm.OriginalTitle) ? null : ovm.OriginalTitle)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetImages(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.ImageMetadata
+            .AsNoTracking()
+            .Where(im => ids.Contains(im.ImageId))
+            .Include(im => im.Artwork)
+            .Include(im => im.Image)
+            .ThenInclude(i => i.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(im => im.Image)
+            .ThenInclude(i => i.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(im => im.ImageId)
+                .Select(g => g.OrderBy(im => im.Id).First())
+                .Map(im => new LibraryBrowseItemResponseModel(
+                    im.ImageId,
+                    LibraryBrowseMediaType.Image,
+                    im.Title ?? string.Empty,
+                    im.Image.LibraryPath.LibraryId,
+                    im.Image.LibraryPath.Library.Name,
+                    ArtworkWithFallback(im, ArtworkKind.Poster, ArtworkKind.Thumbnail),
+                    BestDuration(im.Image.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.Image,
+                    null,
+                    null,
+                    null,
+                    null,
+                    im.ImageId,
+                    null,
+                    string.IsNullOrWhiteSpace(im.OriginalTitle) ? null : im.OriginalTitle)).ToList());
+    }
+
+    public static async Task<List<LibraryBrowseItemResponseModel>> GetRemoteStreams(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.RemoteStreamMetadata
+            .AsNoTracking()
+            .Where(rsm => ids.Contains(rsm.RemoteStreamId))
+            .Include(rsm => rsm.Artwork)
+            .Include(rsm => rsm.RemoteStream)
+            .ThenInclude(rs => rs.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(rsm => rsm.RemoteStream)
+            .ThenInclude(rs => rs.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(rsm => rsm.RemoteStreamId)
+                .Select(g => g.OrderBy(rsm => rsm.Id).First())
+                .Map(rsm => new LibraryBrowseItemResponseModel(
+                    rsm.RemoteStreamId,
+                    LibraryBrowseMediaType.RemoteStream,
+                    rsm.Title ?? string.Empty,
+                    rsm.RemoteStream.LibraryPath.LibraryId,
+                    rsm.RemoteStream.LibraryPath.Library.Name,
+                    ArtworkWithFallback(rsm, ArtworkKind.Thumbnail, ArtworkKind.Poster),
+                    BestDuration(rsm.RemoteStream.MediaVersions),
+                    1,
+                    null,
+                    CollectionType.RemoteStream,
+                    null,
+                    null,
+                    null,
+                    null,
+                    rsm.RemoteStreamId,
+                    null,
+                    string.IsNullOrWhiteSpace(rsm.OriginalTitle) ? null : rsm.OriginalTitle)).ToList());
+    }
+
+    public static TimeSpan? BestDuration(IEnumerable<MediaVersion> versions)
+    {
+        TimeSpan duration = versions
+            .Select(v => v.Duration)
+            .Where(d => d > TimeSpan.Zero)
+            .DefaultIfEmpty()
+            .Max();
+        return duration > TimeSpan.Zero ? duration : null;
+    }
+
+    // Returns a rooted, directly-usable artwork URL for the SPA's <img src>. Blazor pages rely on
+    // GetPosterUrl to prefix "artwork/posters/" and resolve relative to <base href="/">, but the SPA
+    // renders the value raw from under /app/, so the API must root the URL itself (issue #180).
+    public static string Artwork(Metadata metadata, ArtworkKind artworkKind)
+    {
+        string artwork = Optional(metadata.Artwork.FirstOrDefault(a => a.ArtworkKind == artworkKind))
+            .Match(a => a.Path, string.Empty);
+
+        if (string.IsNullOrWhiteSpace(artwork))
+        {
+            return string.Empty;
+        }
+
+        // Absolute URLs are already usable as-is (matches Blazor's GetPosterUrl guard).
+        if (artwork.StartsWith("http://", StringComparison.OrdinalIgnoreCase) ||
+            artwork.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
+        {
+            return artwork;
+        }
+
+        string folder = artworkKind is ArtworkKind.Thumbnail ? "thumbnails" : "posters";
+
+        if (artwork.StartsWith("jellyfin://", StringComparison.OrdinalIgnoreCase))
+        {
+            Url url = JellyfinUrl.RelativeProxyForArtwork(artwork);
+            if (artworkKind is ArtworkKind.Poster or ArtworkKind.Thumbnail)
+            {
+                url.SetQueryParam("fillHeight", 440);
+            }
+
+            return $"/artwork/{folder}/{url}";
+        }
+
+        if (artwork.StartsWith("emby://", StringComparison.OrdinalIgnoreCase))
+        {
+            Url url = EmbyUrl.RelativeProxyForArtwork(artwork);
+            if (artworkKind is ArtworkKind.Poster or ArtworkKind.Thumbnail)
+            {
+                url.SetQueryParam("maxHeight", 440);
+            }
+
+            return $"/artwork/{folder}/{url}";
+        }
+
+        return $"/artwork/{folder}/{artwork}";
+    }
+
+    private static string ArtworkWithFallback(Metadata metadata, ArtworkKind primary, ArtworkKind fallback)
+    {
+        string artwork = Artwork(metadata, primary);
+        return string.IsNullOrWhiteSpace(artwork) ? Artwork(metadata, fallback) : artwork;
+    }
+
+    private static string SeasonTitle(SeasonMetadata metadata)
+    {
+        string showTitle = metadata.Season.Show.ShowMetadata.HeadOrNone()
+            .Map(sm => sm.Title ?? string.Empty)
+            .IfNone(string.Empty);
+        string seasonTitle = metadata.Season.SeasonNumber == 0
+            ? "Specials"
+            : $"Season {metadata.Season.SeasonNumber}";
+        return string.IsNullOrWhiteSpace(showTitle) ? seasonTitle : $"{showTitle} - {seasonTitle}";
+    }
+
+    // Seasons often have no poster of their own; fall back to the parent show's poster (issue #180).
+    private static string SeasonArtwork(SeasonMetadata metadata)
+    {
+        string artwork = Artwork(metadata, ArtworkKind.Poster);
+        if (!string.IsNullOrWhiteSpace(artwork))
+        {
+            return artwork;
+        }
+
+        return metadata.Season.Show.ShowMetadata.HeadOrNone()
+            .Match(sm => Artwork(sm, ArtworkKind.Poster), string.Empty);
+    }
+
+    private static string EpisodeSubtitle(EpisodeMetadata metadata)
+    {
+        string showTitle = metadata.Episode.Season.Show.ShowMetadata.HeadOrNone()
+            .Map(sm => sm.Title ?? string.Empty)
+            .IfNone(string.Empty);
+        int seasonNumber = metadata.Episode.Season.SeasonNumber;
+        string suffix = $"S{seasonNumber}E{metadata.EpisodeNumber}";
+        return string.IsNullOrWhiteSpace(showTitle) ? suffix : $"{showTitle} - {suffix}";
+    }
+
+    private static string MusicVideoSubtitle(MusicVideoMetadata metadata)
+    {
+        string artist = metadata.MusicVideo.Artist.ArtistMetadata.HeadOrNone()
+            .Map(am => am.Title ?? string.Empty)
+            .IfNone(string.Empty);
+        string album = string.IsNullOrWhiteSpace(metadata.Album) ? string.Empty : metadata.Album;
+        if (!string.IsNullOrWhiteSpace(artist) && !string.IsNullOrWhiteSpace(album))
+        {
+            return $"{artist} - {album}";
+        }
+
+        return string.IsNullOrWhiteSpace(artist) ? album : artist;
+    }
+
+    private static string SongSubtitle(SongMetadata metadata)
+    {
+        string artists = string.Join(", ", metadata.Artists ?? []);
+        string album = string.IsNullOrWhiteSpace(metadata.Album) ? string.Empty : metadata.Album;
+        if (!string.IsNullOrWhiteSpace(artists) && !string.IsNullOrWhiteSpace(album))
+        {
+            return $"{artists} - {album}";
+        }
+
+        return string.IsNullOrWhiteSpace(artists) ? album : artists;
+    }
+}

ErsatzTV.Application/LibraryBrowse/Queries/GetLibraryBrowseItems.cs

@@ -0,0 +1,11 @@
+using ErsatzTV.Core.Api.LibraryBrowse;
+
+namespace ErsatzTV.Application.LibraryBrowse;
+
+public record GetLibraryBrowseItems(
+    string Query,
+    int? LibraryId,
+    LibraryBrowseMediaType? MediaType,
+    int PageNum,
+    int PageSize,
+    int? ParentId = null) : IRequest<PagedLibraryBrowseItemsResponseModel>;

ErsatzTV.Application/LibraryBrowse/Queries/GetLibraryBrowseItemsHandler.cs

@@ -0,0 +1,904 @@
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Search;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Search;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.LibraryBrowse;
+
+public class GetLibraryBrowseItemsHandler(
+    ISearchIndex searchIndex,
+    IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetLibraryBrowseItems, PagedLibraryBrowseItemsResponseModel>
+{
+    private const string LibraryIdField = "library_id";
+
+    public async Task<PagedLibraryBrowseItemsResponseModel> Handle(
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        // Drill-in for detail pages: read a parent's children directly (bypassing Lucene) so the SPA can
+        // expand a show into its seasons (#180), a season into its episodes, or an artist into its music
+        // videos (#141/#161). Each reads in the natural display order for that kind.
+        if (request.ParentId.HasValue)
+        {
+            switch (request.MediaType)
+            {
+                case LibraryBrowseMediaType.TelevisionSeason:
+                {
+                    await using TvContext seasonContext =
+                        await dbContextFactory.CreateDbContextAsync(cancellationToken);
+                    return await BrowseSeasonsForShow(seasonContext, request, cancellationToken);
+                }
+                case LibraryBrowseMediaType.Episode:
+                {
+                    await using TvContext episodeContext =
+                        await dbContextFactory.CreateDbContextAsync(cancellationToken);
+                    return await BrowseEpisodesForSeason(episodeContext, request, cancellationToken);
+                }
+                case LibraryBrowseMediaType.MusicVideo:
+                {
+                    await using TvContext musicVideoContext =
+                        await dbContextFactory.CreateDbContextAsync(cancellationToken);
+                    return await BrowseMusicVideosForArtist(musicVideoContext, request, cancellationToken);
+                }
+            }
+        }
+
+        int offset = request.PageNum * request.PageSize;
+        SearchResult mediaResult = await SearchMedia(request, offset, request.PageSize, cancellationToken);
+
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        List<LibraryBrowseItemResponseModel> mediaItems = await HydrateMediaItems(
+            dbContext,
+            mediaResult.Items,
+            cancellationToken);
+
+        int collectionTotal = await CountCollections(dbContext, request, cancellationToken);
+        // Lucene total count can briefly include stale media ids until the async rescan catches up; collection
+        // paging may drift in that window, matching the staleness behavior accepted by the existing search UI.
+        int collectionSkip = Math.Max(0, offset - mediaResult.TotalCount);
+        int collectionTake = request.PageSize - mediaItems.Count;
+        List<LibraryBrowseItemResponseModel> collectionItems = collectionTake > 0
+            ? await GetCollectionItems(dbContext, request, collectionSkip, collectionTake, cancellationToken)
+            : [];
+
+        return new PagedLibraryBrowseItemsResponseModel(
+            mediaResult.TotalCount + collectionTotal,
+            mediaItems.Concat(collectionItems).ToList());
+    }
+
+    private async Task<SearchResult> SearchMedia(
+        GetLibraryBrowseItems request,
+        int offset,
+        int pageSize,
+        CancellationToken cancellationToken)
+    {
+        List<string> typeFilters = MediaTypesFor(request.MediaType).ToList();
+        if (typeFilters.Count == 0)
+        {
+            return new SearchResult([], 0);
+        }
+
+        var clauses = new List<string>
+        {
+            typeFilters.Count == 1
+                ? $"type:{typeFilters[0]}"
+                : $"({string.Join(" OR ", typeFilters.Map(t => $"type:{t}"))})"
+        };
+
+        if (request.LibraryId.HasValue)
+        {
+            clauses.Add($"{LibraryIdField}:{request.LibraryId.Value}");
+        }
+
+        if (!string.IsNullOrWhiteSpace(request.Query))
+        {
+            clauses.Add($"({request.Query})");
+        }
+
+        return await searchIndex.Search(
+            string.Join(" AND ", clauses),
+            string.Empty,
+            offset,
+            pageSize,
+            [LuceneSearchIndex.TitleAndYearSearchField],
+            cancellationToken);
+    }
+
+    private static IEnumerable<string> MediaTypesFor(LibraryBrowseMediaType? mediaType) =>
+        mediaType switch
+        {
+            LibraryBrowseMediaType.Movie => [LuceneSearchIndex.MovieType],
+            LibraryBrowseMediaType.TelevisionShow => [LuceneSearchIndex.ShowType],
+            LibraryBrowseMediaType.TelevisionSeason => [LuceneSearchIndex.SeasonType],
+            LibraryBrowseMediaType.Artist => [LuceneSearchIndex.ArtistType],
+            LibraryBrowseMediaType.Episode => [LuceneSearchIndex.EpisodeType],
+            LibraryBrowseMediaType.MusicVideo => [LuceneSearchIndex.MusicVideoType],
+            LibraryBrowseMediaType.Song => [LuceneSearchIndex.SongType],
+            LibraryBrowseMediaType.OtherVideo => [LuceneSearchIndex.OtherVideoType],
+            LibraryBrowseMediaType.Image => [LuceneSearchIndex.ImageType],
+            LibraryBrowseMediaType.RemoteStream => [LuceneSearchIndex.RemoteStreamType],
+            null =>
+            [
+                LuceneSearchIndex.MovieType,
+                LuceneSearchIndex.ShowType,
+                LuceneSearchIndex.SeasonType,
+                LuceneSearchIndex.ArtistType,
+                LuceneSearchIndex.EpisodeType,
+                LuceneSearchIndex.MusicVideoType,
+                LuceneSearchIndex.SongType,
+                LuceneSearchIndex.OtherVideoType,
+                LuceneSearchIndex.ImageType,
+                LuceneSearchIndex.RemoteStreamType
+            ],
+            _ => []
+        };
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> HydrateMediaItems(
+        TvContext dbContext,
+        List<SearchItem> searchItems,
+        CancellationToken cancellationToken)
+    {
+        if (searchItems.Count == 0)
+        {
+            return [];
+        }
+
+        List<int> movieIds = searchItems.Where(i => i.Type == LuceneSearchIndex.MovieType).Select(i => i.Id).ToList();
+        List<int> showIds = searchItems.Where(i => i.Type == LuceneSearchIndex.ShowType).Select(i => i.Id).ToList();
+        List<int> seasonIds = searchItems.Where(i => i.Type == LuceneSearchIndex.SeasonType).Select(i => i.Id).ToList();
+        List<int> artistIds = searchItems.Where(i => i.Type == LuceneSearchIndex.ArtistType).Select(i => i.Id).ToList();
+        List<int> episodeIds = searchItems.Where(i => i.Type == LuceneSearchIndex.EpisodeType).Select(i => i.Id).ToList();
+        List<int> musicVideoIds =
+            searchItems.Where(i => i.Type == LuceneSearchIndex.MusicVideoType).Select(i => i.Id).ToList();
+        List<int> songIds = searchItems.Where(i => i.Type == LuceneSearchIndex.SongType).Select(i => i.Id).ToList();
+        List<int> otherVideoIds =
+            searchItems.Where(i => i.Type == LuceneSearchIndex.OtherVideoType).Select(i => i.Id).ToList();
+        List<int> imageIds = searchItems.Where(i => i.Type == LuceneSearchIndex.ImageType).Select(i => i.Id).ToList();
+        List<int> remoteStreamIds =
+            searchItems.Where(i => i.Type == LuceneSearchIndex.RemoteStreamType).Select(i => i.Id).ToList();
+
+        Dictionary<(string Type, int Id), LibraryBrowseItemResponseModel> hydrated = [];
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetMovies(dbContext, movieIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.MovieType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetShows(dbContext, showIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.ShowType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetSeasons(dbContext, seasonIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.SeasonType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetArtists(dbContext, artistIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.ArtistType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetEpisodes(dbContext, episodeIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.EpisodeType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetMusicVideos(dbContext, musicVideoIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.MusicVideoType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetSongs(dbContext, songIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.SongType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetOtherVideos(dbContext, otherVideoIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.OtherVideoType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetImages(dbContext, imageIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.ImageType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in
+                 await LibraryBrowseItemMapper.GetRemoteStreams(dbContext, remoteStreamIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.RemoteStreamType, item.Id)] = item;
+        }
+
+        return searchItems
+            .Where(i => hydrated.ContainsKey((i.Type, i.Id)))
+            .Select(i => hydrated[(i.Type, i.Id)])
+            .ToList();
+    }
+
+    private static async Task<PagedLibraryBrowseItemsResponseModel> BrowseSeasonsForShow(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        List<int> allSeasonIds = await dbContext.Seasons
+            .AsNoTracking()
+            .Where(s => s.ShowId == request.ParentId.Value)
+            .OrderBy(s => s.SeasonNumber)
+            .Select(s => s.Id)
+            .ToListAsync(cancellationToken);
+
+        int total = allSeasonIds.Count;
+        List<int> pageIds = allSeasonIds
+            .Skip(request.PageNum * request.PageSize)
+            .Take(request.PageSize)
+            .ToList();
+
+        List<LibraryBrowseItemResponseModel> seasons =
+            await LibraryBrowseItemMapper.GetSeasons(dbContext, pageIds, cancellationToken);
+
+        // GetSeasons groups by season id, so restore the requested season-number order.
+        Dictionary<int, LibraryBrowseItemResponseModel> byId = seasons.ToDictionary(s => s.Id);
+        List<LibraryBrowseItemResponseModel> ordered = pageIds
+            .Where(byId.ContainsKey)
+            .Select(id => byId[id])
+            .ToList();
+
+        return new PagedLibraryBrowseItemsResponseModel(total, ordered);
+    }
+
+    // Drill-in: episodes of a specific season, in episode-number order (#141/#161).
+    private static async Task<PagedLibraryBrowseItemsResponseModel> BrowseEpisodesForSeason(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        List<int> allEpisodeIds = await dbContext.EpisodeMetadata
+            .AsNoTracking()
+            .Where(em => em.Episode.SeasonId == request.ParentId.Value)
+            .OrderBy(em => em.EpisodeNumber)
+            .ThenBy(em => em.EpisodeId)
+            .Select(em => em.EpisodeId)
+            .ToListAsync(cancellationToken);
+
+        // Distinct preserves order (LINQ-to-Objects) for episodes with multiple metadata rows.
+        allEpisodeIds = allEpisodeIds.Distinct().ToList();
+
+        int total = allEpisodeIds.Count;
+        List<int> pageIds = allEpisodeIds
+            .Skip(request.PageNum * request.PageSize)
+            .Take(request.PageSize)
+            .ToList();
+
+        List<LibraryBrowseItemResponseModel> episodes =
+            await LibraryBrowseItemMapper.GetEpisodes(dbContext, pageIds, cancellationToken);
+
+        Dictionary<int, LibraryBrowseItemResponseModel> byId = episodes.ToDictionary(e => e.Id);
+        List<LibraryBrowseItemResponseModel> ordered = pageIds
+            .Where(byId.ContainsKey)
+            .Select(id => byId[id])
+            .ToList();
+
+        return new PagedLibraryBrowseItemsResponseModel(total, ordered);
+    }
+
+    // Drill-in: music videos of a specific artist, in album/track/title order (#141/#161).
+    private static async Task<PagedLibraryBrowseItemsResponseModel> BrowseMusicVideosForArtist(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        List<int> allMusicVideoIds = await dbContext.MusicVideoMetadata
+            .AsNoTracking()
+            .Where(mvm => mvm.MusicVideo.ArtistId == request.ParentId.Value)
+            .OrderBy(mvm => mvm.Album)
+            .ThenBy(mvm => mvm.Track)
+            .ThenBy(mvm => mvm.Title)
+            .ThenBy(mvm => mvm.MusicVideoId)
+            .Select(mvm => mvm.MusicVideoId)
+            .ToListAsync(cancellationToken);
+
+        allMusicVideoIds = allMusicVideoIds.Distinct().ToList();
+
+        int total = allMusicVideoIds.Count;
+        List<int> pageIds = allMusicVideoIds
+            .Skip(request.PageNum * request.PageSize)
+            .Take(request.PageSize)
+            .ToList();
+
+        List<LibraryBrowseItemResponseModel> musicVideos =
+            await LibraryBrowseItemMapper.GetMusicVideos(dbContext, pageIds, cancellationToken);
+
+        Dictionary<int, LibraryBrowseItemResponseModel> byId = musicVideos.ToDictionary(mv => mv.Id);
+        List<LibraryBrowseItemResponseModel> ordered = pageIds
+            .Where(byId.ContainsKey)
+            .Select(id => byId[id])
+            .ToList();
+
+        return new PagedLibraryBrowseItemsResponseModel(total, ordered);
+    }
+
+    private static async Task<int> CountCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        int count = 0;
+        if (ShouldInclude(request.MediaType, LibraryBrowseMediaType.Collection))
+        {
+            count += await FilterCollections(dbContext.Collections.AsNoTracking(), request)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.SmartCollection))
+        {
+            count += await FilterByName(dbContext.SmartCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.MultiCollection))
+        {
+            count += await FilterByName(dbContext.MultiCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.RerunCollection))
+        {
+            count += await FilterByName(dbContext.RerunCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.Playlist))
+        {
+            count += await FilterByName(dbContext.Playlists.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        return count;
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetCollectionItems(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        var results = new List<LibraryBrowseItemResponseModel>();
+
+        int remainingSkip = skip;
+
+        if (ShouldInclude(request.MediaType, LibraryBrowseMediaType.Collection))
+        {
+            IQueryable<Collection> collectionQuery = FilterCollections(dbContext.Collections.AsNoTracking(), request);
+            int count = await collectionQuery.CountAsync(cancellationToken);
+            int pageSkip = Math.Min(remainingSkip, count);
+            remainingSkip -= pageSkip;
+
+            List<Collection> collections = await collectionQuery
+                .OrderBy(c => c.Name)
+                .Skip(pageSkip)
+                .Take(take)
+                .ToListAsync(cancellationToken);
+            List<int> collectionIds = collections.Map(c => c.Id).ToList();
+            Dictionary<int, int> itemCounts = await dbContext.CollectionItems
+                .AsNoTracking()
+                .Where(ci => collectionIds.Contains(ci.CollectionId))
+                .GroupBy(ci => ci.CollectionId)
+                .Select(g => new { CollectionId = g.Key, Count = g.Count() })
+                .ToDictionaryAsync(g => g.CollectionId, g => g.Count, cancellationToken);
+            Dictionary<int, TimeSpan?> durations = await GetManualCollectionDurations(
+                dbContext,
+                collectionIds,
+                cancellationToken);
+            Dictionary<int, string> artwork = await GetManualCollectionArtwork(dbContext, collectionIds, cancellationToken);
+
+            results.AddRange(collections.Map(c => new LibraryBrowseItemResponseModel(
+                c.Id,
+                LibraryBrowseMediaType.Collection,
+                c.Name,
+                null,
+                null,
+                artwork.TryGetValue(c.Id, out string poster) ? poster : string.Empty,
+                durations.TryGetValue(c.Id, out TimeSpan? duration) ? duration : null,
+                itemCounts.TryGetValue(c.Id, out int itemCount) ? itemCount : 0,
+                "Manual",
+                CollectionType.Collection,
+                c.Id,
+                null,
+                null,
+                null,
+                null,
+                null)));
+        }
+
+        if (results.Count >= take || request.LibraryId.HasValue)
+        {
+            return results.Take(take).ToList();
+        }
+
+        remainingSkip = await AppendSmartCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        remainingSkip = await AppendMultiCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        remainingSkip = await AppendRerunCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        await AppendPlaylists(dbContext, request, results, remainingSkip, take, cancellationToken);
+        return results.Take(take).ToList();
+    }
+
+    private static async Task<int> AppendSmartCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.SmartCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<SmartCollection> query = FilterByName(dbContext.SmartCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<SmartCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.SmartCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            null,
+            "Smart",
+            CollectionType.SmartCollection,
+            null,
+            null,
+            c.Id,
+            null,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task<int> AppendMultiCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.MultiCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<MultiCollection> query = FilterByName(dbContext.MultiCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<MultiCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+        List<int> ids = page.Map(c => c.Id).ToList();
+        Dictionary<int, int> collectionCounts = await dbContext.Set<MultiCollectionItem>()
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.MultiCollectionId))
+            .GroupBy(i => i.MultiCollectionId)
+            .Select(g => new { MultiCollectionId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.MultiCollectionId, g => g.Count, cancellationToken);
+        Dictionary<int, int> smartCollectionCounts = await dbContext.Set<MultiCollectionSmartItem>()
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.MultiCollectionId))
+            .GroupBy(i => i.MultiCollectionId)
+            .Select(g => new { MultiCollectionId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.MultiCollectionId, g => g.Count, cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.MultiCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            (collectionCounts.TryGetValue(c.Id, out int collectionCount) ? collectionCount : 0) +
+            (smartCollectionCounts.TryGetValue(c.Id, out int smartCollectionCount) ? smartCollectionCount : 0),
+            "Multi",
+            CollectionType.MultiCollection,
+            null,
+            c.Id,
+            null,
+            null,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task<int> AppendRerunCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.RerunCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<RerunCollection> query = FilterByName(dbContext.RerunCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<RerunCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.RerunCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            null,
+            "Rerun",
+            // RerunFirstRun addresses the first-run side; the SPA can substitute RerunRerun for rerun schedule items.
+            CollectionType.RerunFirstRun,
+            null,
+            null,
+            null,
+            c.Id,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task AppendPlaylists(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.Playlist) || results.Count >= take)
+        {
+            return;
+        }
+
+        IQueryable<Playlist> query = FilterByName(dbContext.Playlists.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<Playlist> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+        List<int> ids = page.Map(c => c.Id).ToList();
+        Dictionary<int, int> itemCounts = await dbContext.PlaylistItems
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.PlaylistId))
+            .GroupBy(i => i.PlaylistId)
+            .Select(g => new { PlaylistId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.PlaylistId, g => g.Count, cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.Playlist,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            itemCounts.TryGetValue(c.Id, out int itemCount) ? itemCount : 0,
+            null,
+            CollectionType.Playlist,
+            null,
+            null,
+            null,
+            null,
+            null,
+            c.Id)));
+    }
+
+    private static IQueryable<Collection> FilterCollections(
+        IQueryable<Collection> query,
+        GetLibraryBrowseItems request)
+    {
+        query = FilterByName(query, request.Query);
+        if (request.LibraryId.HasValue)
+        {
+            query = query.Where(c => c.MediaItems.Any(mi => mi.LibraryPath.LibraryId == request.LibraryId.Value));
+        }
+
+        return query;
+    }
+
+    private static IQueryable<T> FilterByName<T>(IQueryable<T> query, string searchQuery)
+        where T : class
+    {
+        if (string.IsNullOrWhiteSpace(searchQuery))
+        {
+            return query;
+        }
+
+        return query.Where(c => EF.Functions.Like(EF.Property<string>(c, "Name"), $"%{EscapeLike(searchQuery)}%", "\\"));
+    }
+
+    private static bool ShouldInclude(LibraryBrowseMediaType? requestType, LibraryBrowseMediaType itemType) =>
+        requestType is null || requestType == itemType;
+
+    private static async Task<Dictionary<int, TimeSpan?>> GetManualCollectionDurations(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken)
+    {
+        List<CollectionMediaItem> items = await GetCollectionMediaItems(dbContext, collectionIds, cancellationToken);
+        List<int> mediaItemIds = items.Map(i => i.MediaItemId).Distinct().ToList();
+        Dictionary<int, TimeSpan> mediaItemDurations = [];
+
+        foreach (Movie movie in await dbContext.Movies
+                     .AsNoTracking()
+                     .Where(m => mediaItemIds.Contains(m.Id))
+                     .Include(m => m.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(movie.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[movie.Id] = duration.Value;
+            }
+        }
+
+        foreach (Episode episode in await dbContext.Episodes
+                     .AsNoTracking()
+                     .Where(e => mediaItemIds.Contains(e.Id))
+                     .Include(e => e.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(episode.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[episode.Id] = duration.Value;
+            }
+        }
+
+        foreach (MusicVideo musicVideo in await dbContext.MusicVideos
+                     .AsNoTracking()
+                     .Where(mv => mediaItemIds.Contains(mv.Id))
+                     .Include(mv => mv.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(musicVideo.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[musicVideo.Id] = duration.Value;
+            }
+        }
+
+        foreach (OtherVideo otherVideo in await dbContext.OtherVideos
+                     .AsNoTracking()
+                     .Where(ov => mediaItemIds.Contains(ov.Id))
+                     .Include(ov => ov.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(otherVideo.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[otherVideo.Id] = duration.Value;
+            }
+        }
+
+        foreach (Song song in await dbContext.Songs
+                     .AsNoTracking()
+                     .Where(s => mediaItemIds.Contains(s.Id))
+                     .Include(s => s.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(song.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[song.Id] = duration.Value;
+            }
+        }
+
+        foreach (Image image in await dbContext.Images
+                     .AsNoTracking()
+                     .Where(i => mediaItemIds.Contains(i.Id))
+                     .Include(i => i.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(image.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[image.Id] = duration.Value;
+            }
+        }
+
+        foreach (RemoteStream remoteStream in await dbContext.RemoteStreams
+                     .AsNoTracking()
+                     .Where(rs => mediaItemIds.Contains(rs.Id))
+                     .Include(rs => rs.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = LibraryBrowseItemMapper.BestDuration(remoteStream.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[remoteStream.Id] = duration.Value;
+            }
+        }
+
+        return items
+            .Where(i => mediaItemDurations.ContainsKey(i.MediaItemId))
+            .GroupBy(i => i.CollectionId)
+            .ToDictionary(
+                g => g.Key,
+                g => (TimeSpan?)g.Aggregate(TimeSpan.Zero, (sum, item) => sum + mediaItemDurations[item.MediaItemId]));
+    }
+
+    private static async Task<Dictionary<int, string>> GetManualCollectionArtwork(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken)
+    {
+        List<CollectionMediaItem> items = await GetCollectionMediaItems(dbContext, collectionIds, cancellationToken);
+        List<int> mediaItemIds = items.Map(i => i.MediaItemId).Distinct().ToList();
+        Dictionary<int, string> mediaItemArtwork = [];
+
+        foreach (MovieMetadata metadata in await dbContext.MovieMetadata
+                     .AsNoTracking()
+                     .Where(mm => mediaItemIds.Contains(mm.MovieId))
+                     .Include(mm => mm.Artwork)
+                     .OrderBy(mm => mm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.MovieId))
+            {
+                mediaItemArtwork[metadata.MovieId] = poster;
+            }
+        }
+
+        foreach (ShowMetadata metadata in await dbContext.ShowMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.ShowId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.ShowId))
+            {
+                mediaItemArtwork[metadata.ShowId] = poster;
+            }
+        }
+
+        foreach (SeasonMetadata metadata in await dbContext.SeasonMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.SeasonId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.SeasonId))
+            {
+                mediaItemArtwork[metadata.SeasonId] = poster;
+            }
+        }
+
+        foreach (OtherVideoMetadata metadata in await dbContext.OtherVideoMetadata
+                     .AsNoTracking()
+                     .Where(ovm => mediaItemIds.Contains(ovm.OtherVideoId))
+                     .Include(ovm => ovm.Artwork)
+                     .OrderBy(ovm => ovm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.OtherVideoId))
+            {
+                mediaItemArtwork[metadata.OtherVideoId] = poster;
+            }
+        }
+
+        foreach (SongMetadata metadata in await dbContext.SongMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.SongId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.SongId))
+            {
+                mediaItemArtwork[metadata.SongId] = poster;
+            }
+        }
+
+        foreach (ImageMetadata metadata in await dbContext.ImageMetadata
+                     .AsNoTracking()
+                     .Where(im => mediaItemIds.Contains(im.ImageId))
+                     .Include(im => im.Artwork)
+                     .OrderBy(im => im.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.ImageId))
+            {
+                mediaItemArtwork[metadata.ImageId] = poster;
+            }
+        }
+
+        foreach (RemoteStreamMetadata metadata in await dbContext.RemoteStreamMetadata
+                     .AsNoTracking()
+                     .Where(rsm => mediaItemIds.Contains(rsm.RemoteStreamId))
+                     .Include(rsm => rsm.Artwork)
+                     .OrderBy(rsm => rsm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = LibraryBrowseItemMapper.Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.RemoteStreamId))
+            {
+                mediaItemArtwork[metadata.RemoteStreamId] = poster;
+            }
+        }
+
+        return items
+            .Where(i => mediaItemArtwork.ContainsKey(i.MediaItemId))
+            .GroupBy(i => i.CollectionId)
+            .ToDictionary(
+                g => g.Key,
+                g => mediaItemArtwork[g.OrderBy(i => i.CustomIndex ?? int.MaxValue).ThenBy(i => i.MediaItemId).First().MediaItemId]);
+    }
+
+    private static async Task<List<CollectionMediaItem>> GetCollectionMediaItems(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken) =>
+        await dbContext.CollectionItems
+            .AsNoTracking()
+            .Where(ci => collectionIds.Contains(ci.CollectionId))
+            .Select(ci => new CollectionMediaItem(ci.CollectionId, ci.MediaItemId, ci.CustomIndex))
+            .ToListAsync(cancellationToken);
+
+    private static string EscapeLike(string searchQuery) =>
+        searchQuery
+            .Replace("\\", "\\\\", StringComparison.Ordinal)
+            .Replace("%", "\\%", StringComparison.Ordinal)
+            .Replace("_", "\\_", StringComparison.Ordinal);
+
+    private sealed record CollectionMediaItem(int CollectionId, int MediaItemId, int? CustomIndex);
+}

ErsatzTV.Application/MediaCollections/Queries/GetCollectionItems.cs

@@ -0,0 +1,7 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.LibraryBrowse;
+
+namespace ErsatzTV.Application.MediaCollections;
+
+public record GetCollectionItems(int Id, int PageNum, int PageSize)
+    : IRequest<Either<BaseError, PagedLibraryBrowseItemsResponseModel>>;

ErsatzTV.Application/MediaCollections/Queries/GetCollectionItemsHandler.cs

@@ -0,0 +1,56 @@
+using ErsatzTV.Application.LibraryBrowse;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.MediaCollections;
+
+public class GetCollectionItemsHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetCollectionItems, Either<BaseError, PagedLibraryBrowseItemsResponseModel>>
+{
+    public async Task<Either<BaseError, PagedLibraryBrowseItemsResponseModel>> Handle(
+        GetCollectionItems request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        bool exists = await dbContext.Collections
+            .AsNoTracking()
+            .AnyAsync(c => c.Id == request.Id, cancellationToken);
+        if (!exists)
+        {
+            return new NotFoundError($"Collection {request.Id} does not exist.");
+        }
+
+        // The collection graph is bounded, so load every member id and hydrate them in one shared
+        // pass (LibraryBrowseItemMapper), then order + page in-memory. Mixed media kinds are supported
+        // because MediaItem ids are globally unique across kinds.
+        List<int> mediaItemIds = await dbContext.CollectionItems
+            .AsNoTracking()
+            .Where(ci => ci.CollectionId == request.Id)
+            .Select(ci => ci.MediaItemId)
+            .ToListAsync(cancellationToken);
+
+        List<LibraryBrowseItemResponseModel> all =
+            await LibraryBrowseItemMapper.HydrateMediaItemsByIds(dbContext, mediaItemIds, cancellationToken);
+
+        // Stable title ordering mirrors the library-browse handler (which orders its rows by name),
+        // giving the SPA a deterministic, browsable list independent of collection insertion order.
+        List<LibraryBrowseItemResponseModel> ordered = all
+            .OrderBy(i => i.Title, StringComparer.OrdinalIgnoreCase)
+            .ThenBy(i => i.Id)
+            .ToList();
+
+        int pageNum = Math.Max(0, request.PageNum);
+        int pageSize = Math.Clamp(request.PageSize, 1, 100);
+
+        List<LibraryBrowseItemResponseModel> page = ordered
+            .Skip(pageNum * pageSize)
+            .Take(pageSize)
+            .ToList();
+
+        return new PagedLibraryBrowseItemsResponseModel(ordered.Count, page);
+    }
+}

ErsatzTV.Application/MediaSources/Queries/GetAllMediaSourcesForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.MediaSources;
+
+namespace ErsatzTV.Application.MediaSources;
+
+public record GetAllMediaSourcesForApi : IRequest<List<MediaSourceResponseModel>>;

ErsatzTV.Application/MediaSources/Queries/GetAllMediaSourcesForApiHandler.cs

@@ -0,0 +1,146 @@
+#nullable enable
+using ErsatzTV.Core.Api.MediaSources;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.MediaSources;
+
+public class GetAllMediaSourcesForApiHandler(
+    IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetAllMediaSourcesForApi, List<MediaSourceResponseModel>>
+{
+    public async Task<List<MediaSourceResponseModel>> Handle(
+        GetAllMediaSourcesForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        List<MediaSource> mediaSources = await dbContext.MediaSources
+                .AsNoTracking()
+                .Include(s => s.Libraries)
+                .ThenInclude(l => l.Paths)
+                .ToListAsync(cancellationToken);
+
+        Dictionary<int, int> itemCountsByLibrary = await GetItemCountsByLibrary(dbContext, cancellationToken);
+        Dictionary<int, string> addressByMediaSourceId = await GetConnectionAddresses(dbContext, cancellationToken);
+
+        var result = new List<MediaSourceResponseModel>();
+        foreach (MediaSource mediaSource in mediaSources)
+        {
+            List<MediaSourceLibraryResponseModel> libraryModels = mediaSource.Libraries
+                .Filter(ShouldIncludeLibrary)
+                .OrderBy(l => l.MediaKind)
+                .ThenBy(l => l.Name)
+                .Map(l => new MediaSourceLibraryResponseModel(
+                    l.Id,
+                    l.Name,
+                    l.MediaKind,
+                    l.LastScan,
+                    itemCountsByLibrary.TryGetValue(l.Id, out int count) ? count : 0))
+                .ToList();
+
+            string? address = addressByMediaSourceId.TryGetValue(mediaSource.Id, out string? a) ? a : null;
+
+            result.Add(
+                new MediaSourceResponseModel(
+                    mediaSource.Id,
+                    GetKind(mediaSource),
+                    GetName(mediaSource),
+                    address,
+                    libraryModels));
+        }
+
+        return result
+            .OrderBy(s => s.Kind == "Local" ? 0 : 1)
+            .ThenBy(s => s.Kind)
+            .ThenBy(s => s.Name)
+            .ToList();
+    }
+
+    private static async Task<Dictionary<int, int>> GetItemCountsByLibrary(
+        TvContext dbContext,
+        CancellationToken cancellationToken)
+    {
+        // EF instead of Dapper: with zero rows, Microsoft.Data.Sqlite reports the
+        // COUNT(*) column as BLOB, so Dapper builds an incompatible deserializer
+        // and every fresh (empty) database returned 500 from this endpoint.
+        var counts = await dbContext.MediaItems
+            .AsNoTracking()
+            .GroupBy(mi => mi.LibraryPath.LibraryId)
+            .Select(g => new { LibraryId = g.Key, Count = g.Count() })
+            .ToListAsync(cancellationToken);
+
+        return counts.ToDictionary(c => c.LibraryId, c => c.Count);
+    }
+
+    private static async Task<Dictionary<int, string>> GetConnectionAddresses(
+        TvContext dbContext,
+        CancellationToken cancellationToken)
+    {
+        var addresses = new Dictionary<int, string>();
+
+        foreach (PlexMediaSource plex in await dbContext.PlexMediaSources
+                     .AsNoTracking()
+                     .Include(s => s.Connections)
+                     .ToListAsync(cancellationToken))
+        {
+            foreach (PlexConnection connection in Optional(plex.Connections.SingleOrDefault(c => c.IsActive)))
+            {
+                addresses[plex.Id] = connection.Uri;
+            }
+        }
+
+        foreach (JellyfinMediaSource jellyfin in await dbContext.JellyfinMediaSources
+                     .AsNoTracking()
+                     .Include(s => s.Connections)
+                     .ToListAsync(cancellationToken))
+        {
+            foreach (JellyfinConnection connection in jellyfin.Connections.HeadOrNone())
+            {
+                addresses[jellyfin.Id] = connection.Address;
+            }
+        }
+
+        foreach (EmbyMediaSource emby in await dbContext.EmbyMediaSources
+                     .AsNoTracking()
+                     .Include(s => s.Connections)
+                     .ToListAsync(cancellationToken))
+        {
+            foreach (EmbyConnection connection in emby.Connections.HeadOrNone())
+            {
+                addresses[emby.Id] = connection.Address;
+            }
+        }
+
+        return addresses;
+    }
+
+    private static bool ShouldIncludeLibrary(Library library) =>
+        library switch
+        {
+            LocalLibrary => library.Paths.Count > 0,
+            PlexLibrary plex => plex.ShouldSyncItems,
+            JellyfinLibrary jellyfin => jellyfin.ShouldSyncItems,
+            EmbyLibrary emby => emby.ShouldSyncItems,
+            _ => false
+        };
+
+    private static string GetKind(MediaSource mediaSource) =>
+        mediaSource switch
+        {
+            PlexMediaSource => "Plex",
+            JellyfinMediaSource => "Jellyfin",
+            EmbyMediaSource => "Emby",
+            _ => "Local"
+        };
+
+    private static string GetName(MediaSource mediaSource) =>
+        mediaSource switch
+        {
+            PlexMediaSource plex => plex.ServerName,
+            JellyfinMediaSource jellyfin => jellyfin.ServerName,
+            EmbyMediaSource emby => emby.ServerName,
+            _ => "Local"
+        };
+}

ErsatzTV.Application/Playouts/Commands/UpdateExternalJsonPlayoutHandler.cs

@@ -54,7 +54,9 @@ public class
             playout.ProgramSchedule?.Name ?? string.Empty,
             playout.ScheduleFile,
             playout.DailyRebuildTime,
-            playout.BuildStatus);
+            playout.BuildStatus,
+            playout.DecoId,
+            playout.Deco?.Name);
     }
 
     private static Task<Validation<BaseError, Playout>> Validate(

ErsatzTV.Application/Playouts/Commands/UpdatePlayoutHandler.cs

@@ -46,7 +46,9 @@ public class UpdatePlayoutHandler : IRequestHandler<UpdatePlayout, Either<BaseEr
             playout.ProgramSchedule?.Name ?? string.Empty,
             playout.ScheduleFile,
             playout.DailyRebuildTime,
-            playout.BuildStatus);
+            playout.BuildStatus,
+            playout.DecoId,
+            playout.Deco?.Name);
     }
 
     private static Task<Validation<BaseError, Playout>> Validate(

ErsatzTV.Application/Playouts/Commands/UpdateScriptedPlayoutHandler.cs

@@ -49,7 +49,9 @@ public class
             playout.ProgramSchedule?.Name ?? string.Empty,
             playout.ScheduleFile,
             playout.DailyRebuildTime,
-            playout.BuildStatus);
+            playout.BuildStatus,
+            playout.DecoId,
+            playout.Deco?.Name);
     }
 
     private async Task<Validation<BaseError, Playout>> Validate(

ErsatzTV.Application/Playouts/Commands/UpdateSequentialPlayoutHandler.cs

@@ -54,7 +54,9 @@ public class
             playout.ProgramSchedule?.Name ?? string.Empty,
             playout.ScheduleFile,
             playout.DailyRebuildTime,
-            playout.BuildStatus);
+            playout.BuildStatus,
+            playout.DecoId,
+            playout.Deco?.Name);
     }
 
     private static Task<Validation<BaseError, Playout>> Validate(

ErsatzTV.Application/Playouts/Mapper.cs

@@ -15,7 +15,11 @@ internal static class Mapper
             playout.ProgramScheduleId == null ? string.Empty : playout.ProgramSchedule.Name,
             playout.ScheduleFile,
             playout.DailyRebuildTime,
-            playout.BuildStatus);
+            playout.BuildStatus,
+            playout.DecoId,
+            // the paged-playouts query does not eager-load Deco (the list response does not surface
+            // the default deco); GetPlayoutById includes it for the detail response
+            playout.Deco?.Name);
 
     internal static PlayoutItemViewModel ProjectToViewModel(PlayoutItem playoutItem) =>
         new(

ErsatzTV.Application/Playouts/PlayoutNameViewModel.cs

@@ -11,7 +11,9 @@ public record PlayoutNameViewModel(
     string ScheduleName,
     string ScheduleFile,
     TimeSpan? DbDailyRebuildTime,
-    PlayoutBuildStatus BuildStatus)
+    PlayoutBuildStatus BuildStatus,
+    int? DecoId,
+    string DecoName)
 {
     public Option<TimeSpan> DailyRebuildTime => Optional(DbDailyRebuildTime);
 

ErsatzTV.Application/Playouts/Queries/GetPlayoutByIdHandler.cs

@@ -16,6 +16,8 @@ public class GetPlayoutByIdHandler(IDbContextFactory<TvContext> dbContextFactory
             .AsNoTracking()
             .Include(p => p.ProgramSchedule)
             .Include(p => p.Channel)
+            .Include(p => p.BuildStatus)
+            .Include(p => p.Deco)
             .SelectOneAsync(p => p.Id, p => p.Id == request.PlayoutId, cancellationToken)
             .MapT(p => new PlayoutNameViewModel(
                 p.Id,
@@ -26,6 +28,8 @@ public class GetPlayoutByIdHandler(IDbContextFactory<TvContext> dbContextFactory
                 p.ProgramScheduleId == null ? string.Empty : p.ProgramSchedule.Name,
                 p.ScheduleFile,
                 p.DailyRebuildTime,
-                p.BuildStatus));
+                p.BuildStatus,
+                p.DecoId,
+                p.DecoId == null ? null : p.Deco.Name));
     }
 }

ErsatzTV.Application/ProgramSchedules/ProgramScheduleItemViewModel.cs

@@ -44,6 +44,33 @@ public abstract record ProgramScheduleItemViewModel(
     string PreferredSubtitleLanguageCode,
     ChannelSubtitleMode? SubtitleMode)
 {
+    /// <summary>
+    ///     A rough estimate, in wall-clock time, of how long a single pass of this schedule item will play,
+    ///     derived from the aggregated playout runtimes of the referenced content.
+    ///     <para>
+    ///         Semantics by <see cref="PlayoutMode" />:
+    ///         <list type="bullet">
+    ///             <item><b>One</b> — the average runtime of one item in the referenced collection.</item>
+    ///             <item>
+    ///                 <b>Multiple</b> — the average item runtime multiplied by the configured count
+    ///                 (<see cref="MultipleMode.Count" />), or the whole collection runtime for
+    ///                 <see cref="MultipleMode.CollectionSize" />. An expression-based (non-integer)
+    ///                 count cannot be evaluated here and yields <c>null</c>.
+    ///             </item>
+    ///             <item><b>Flood</b> — always <c>null</c>: a flood item fills the remaining time and is unbounded.</item>
+    ///             <item><b>Duration</b> — the explicit <c>playoutDuration</c> setting on the item.</item>
+    ///         </list>
+    ///     </para>
+    ///     <para>
+    ///         <c>null</c> whenever a bounded estimate cannot be produced — an unbounded mode (Flood),
+    ///         a referenced collection with no items that have a known positive duration, a Multiple mode other
+    ///         than Count/CollectionSize, or a collection type other than <see cref="CollectionType.Collection" />
+    ///         (smart/multi/playlist/search/rerun/show/season/artist references are not aggregated in this pass).
+    ///         Callers should treat a <c>null</c> as "unknown", never as zero.
+    ///     </para>
+    /// </summary>
+    public TimeSpan? DurationEstimate { get; init; }
+
     public string Name => CollectionType switch
     {
         CollectionType.Collection => Collection?.Name,

ErsatzTV.Application/ProgramSchedules/ProgramScheduleItemsWithDurationViewModel.cs

@@ -0,0 +1,18 @@
+namespace ErsatzTV.Application.ProgramSchedules;
+
+/// <summary>
+///     The items of a schedule together with computed runtime estimates. Each item carries its own
+///     <see cref="ProgramScheduleItemViewModel.DurationEstimate" /> (nullable — see that property for
+///     the per-mode semantics), and <see cref="TotalDurationEstimate" /> is the sum of the items that
+///     could be estimated.
+/// </summary>
+/// <param name="Items">The schedule items, each with a nullable <c>DurationEstimate</c>.</param>
+/// <param name="TotalDurationEstimate">
+///     The sum of every non-null per-item estimate, i.e. a rough runtime for a single pass through the
+///     estimable items. <c>null</c> when no item in the schedule could be estimated (for example a
+///     schedule made up entirely of Flood items, or of collection types that are not aggregated).
+///     Because unbounded items contribute nothing, this is a lower bound, never an exact schedule length.
+/// </param>
+public record ProgramScheduleItemsWithDurationViewModel(
+    List<ProgramScheduleItemViewModel> Items,
+    TimeSpan? TotalDurationEstimate);

ErsatzTV.Application/ProgramSchedules/Queries/GetProgramScheduleItemsWithDurations.cs

@@ -0,0 +1,4 @@
+namespace ErsatzTV.Application.ProgramSchedules;
+
+public record GetProgramScheduleItemsWithDurations(int Id)
+    : IRequest<ProgramScheduleItemsWithDurationViewModel>;

ErsatzTV.Application/ProgramSchedules/Queries/GetProgramScheduleItemsWithDurationsHandler.cs

@@ -0,0 +1,70 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Extensions;
+using ErsatzTV.Core.Interfaces.Repositories;
+using static ErsatzTV.Application.ProgramSchedules.ScheduleItemDurationEstimator;
+
+namespace ErsatzTV.Application.ProgramSchedules;
+
+public class GetProgramScheduleItemsWithDurationsHandler(
+    IMediator mediator,
+    IMediaCollectionRepository mediaCollectionRepository)
+    : IRequestHandler<GetProgramScheduleItemsWithDurations, ProgramScheduleItemsWithDurationViewModel>
+{
+    public async Task<ProgramScheduleItemsWithDurationViewModel> Handle(
+        GetProgramScheduleItemsWithDurations request,
+        CancellationToken cancellationToken)
+    {
+        List<ProgramScheduleItemViewModel> items =
+            await mediator.Send(new GetProgramScheduleItems(request.Id), cancellationToken);
+
+        Dictionary<int, CollectionDuration> durationsByCollectionId =
+            await AggregateReferencedCollections(items);
+
+        var itemsWithEstimates = items
+            .Map(item => item with { DurationEstimate = Estimate(item, durationsByCollectionId) })
+            .ToList();
+
+        List<TimeSpan> estimates = itemsWithEstimates
+            .Map(item => Optional(item.DurationEstimate))
+            .Somes()
+            .ToList();
+
+        TimeSpan? total = estimates.Count > 0
+            ? TimeSpan.FromTicks(estimates.Sum(estimate => estimate.Ticks))
+            : null;
+
+        return new ProgramScheduleItemsWithDurationViewModel(itemsWithEstimates, total);
+    }
+
+    // Aggregate MediaVersion.Duration once per distinct referenced collection (not per item). Only plain
+    // collections are resolved here; other reference types are estimated as null (see DurationEstimate docs).
+    private async Task<Dictionary<int, CollectionDuration>> AggregateReferencedCollections(
+        IReadOnlyList<ProgramScheduleItemViewModel> items)
+    {
+        List<int> collectionIds = items
+            .Filter(item => item.CollectionType is CollectionType.Collection && item.Collection is not null)
+            .Filter(item => item.PlayoutMode is PlayoutMode.One or PlayoutMode.Multiple)
+            .Map(item => item.Collection.Id)
+            .Distinct()
+            .ToList();
+
+        var result = new Dictionary<int, CollectionDuration>();
+        foreach (int collectionId in collectionIds)
+        {
+            List<MediaItem> mediaItems = await mediaCollectionRepository.GetItems(collectionId);
+
+            List<TimeSpan> durations = mediaItems
+                .Map(mediaItem => mediaItem.GetDurationForPlayout())
+                .Filter(duration => duration > TimeSpan.Zero)
+                .ToList();
+
+            if (durations.Count > 0)
+            {
+                var total = TimeSpan.FromTicks(durations.Sum(duration => duration.Ticks));
+                result[collectionId] = new CollectionDuration(total, durations.Count);
+            }
+        }
+
+        return result;
+    }
+}

ErsatzTV.Application/ProgramSchedules/ScheduleItemDurationEstimator.cs

@@ -0,0 +1,73 @@
+using System.Globalization;
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Application.ProgramSchedules;
+
+/// <summary>
+///     Pure computation of per-item runtime estimates from pre-aggregated collection durations.
+///     Kept separate from the query handler so the (non-trivial) per-mode math can be unit-tested
+///     without a database. See <see cref="ProgramScheduleItemViewModel.DurationEstimate" /> for the
+///     documented semantics this implements.
+/// </summary>
+internal static class ScheduleItemDurationEstimator
+{
+    /// <summary>
+    ///     Aggregate runtime of a single referenced collection: the total runtime of every item with a
+    ///     known non-zero duration, and how many such items there are.
+    /// </summary>
+    public sealed record CollectionDuration(TimeSpan Total, int ItemCount)
+    {
+        public TimeSpan? Average => ItemCount > 0 ? Total / ItemCount : null;
+    }
+
+    /// <summary>
+    ///     Estimate the runtime of one pass of <paramref name="item" />, or <c>null</c> when no bounded
+    ///     estimate is possible. <paramref name="durationsByCollectionId" /> holds aggregates only for the
+    ///     plain collections that were resolved; a missing entry yields <c>null</c>.
+    /// </summary>
+    public static TimeSpan? Estimate(
+        ProgramScheduleItemViewModel item,
+        IReadOnlyDictionary<int, CollectionDuration> durationsByCollectionId)
+    {
+        if (item is ProgramScheduleItemDurationViewModel durationItem)
+        {
+            return durationItem.PlayoutDuration;
+        }
+
+        // only plain collections are aggregated in this pass
+        if (item.CollectionType is not CollectionType.Collection || item.Collection is null)
+        {
+            return null;
+        }
+
+        if (!durationsByCollectionId.TryGetValue(item.Collection.Id, out CollectionDuration duration))
+        {
+            return null;
+        }
+
+        return item switch
+        {
+            // one item per pass -> the average item runtime
+            ProgramScheduleItemOneViewModel => duration.Average,
+
+            // a fixed count of items, or the whole collection once
+            ProgramScheduleItemMultipleViewModel multiple => EstimateMultiple(multiple, duration),
+
+            // Flood is an unbounded fill; Duration is handled above from its explicit playoutDuration.
+            _ => null
+        };
+    }
+
+    private static TimeSpan? EstimateMultiple(
+        ProgramScheduleItemMultipleViewModel multiple,
+        CollectionDuration duration) =>
+        multiple.MultipleMode switch
+        {
+            MultipleMode.Count when
+                int.TryParse(multiple.Count, NumberStyles.Integer, CultureInfo.InvariantCulture, out int count)
+                && count > 0
+                && duration.Average is { } average => average * count,
+            MultipleMode.CollectionSize => duration.Total,
+            _ => null
+        };
+}

ErsatzTV.Application/Resolutions/Commands/DeleteCustomResolutionHandler.cs

@@ -1,6 +1,7 @@
 using Dapper;
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
 using Microsoft.EntityFrameworkCore;
@@ -18,23 +19,28 @@ public class DeleteCustomResolutionHandler : IRequestHandler<DeleteCustomResolut
     {
         await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
 
-        Option<Resolution> maybeResolution = await dbContext.Resolutions
+        Option<Resolution> maybeAnyResolution = await dbContext.Resolutions
             .AsNoTracking()
-            .SelectOneAsync(p => p.Id, p => p.Id == request.ResolutionId && p.IsCustom == true, cancellationToken);
+            .SelectOneAsync(p => p.Id, p => p.Id == request.ResolutionId, cancellationToken);
 
-        foreach (Resolution resolution in maybeResolution)
+        foreach (Resolution existingResolution in maybeAnyResolution)
         {
+            if (!existingResolution.IsCustom)
+            {
+                return BaseError.New($"Resolution {request.ResolutionId} is not a custom resolution.");
+            }
+
             // reset any ffmpeg profiles using this resolution to 1920x1080
             await dbContext.Connection.ExecuteAsync(
                 @"UPDATE FFmpegProfile SET ResolutionId = 3 WHERE ResolutionId = @ResolutionId",
                 new { request.ResolutionId });
 
-            dbContext.Resolutions.Remove(resolution);
+            dbContext.Resolutions.Remove(existingResolution);
             await dbContext.SaveChangesAsync(cancellationToken);
         }
 
-        return maybeResolution.IsNone
-            ? BaseError.New($"Resolution {request.ResolutionId} does not exist.")
+        return maybeAnyResolution.IsNone
+            ? new NotFoundError($"Resolution {request.ResolutionId} does not exist.")
             : Option<BaseError>.None;
     }
 }

ErsatzTV.Application/Scheduling/Commands/CreateBlockHandler.cs

@@ -25,13 +25,29 @@ public class CreateBlockHandler(IDbContextFactory<TvContext> dbContextFactory)
         return Mapper.ProjectToViewModel(block);
     }
 
-    private static async Task<Validation<BaseError, Block>> Validate(TvContext dbContext, CreateBlock request) =>
-        await ValidateBlockName(dbContext, request).MapT(name => new Block
+    private static async Task<Validation<BaseError, Block>> Validate(TvContext dbContext, CreateBlock request)
+    {
+        Validation<BaseError, Unit> blockGroupValidation = await ValidateBlockGroupExists(dbContext, request);
+        Validation<BaseError, string> nameValidation = await ValidateBlockName(dbContext, request);
+
+        return (blockGroupValidation, nameValidation).Apply((_, name) => new Block
         {
             BlockGroupId = request.BlockGroupId,
             Name = name,
             Minutes = 30
         });
+    }
+
+    private static async Task<Validation<BaseError, Unit>> ValidateBlockGroupExists(
+        TvContext dbContext,
+        CreateBlock request)
+    {
+        bool blockGroupExists = await dbContext.BlockGroups.AnyAsync(bg => bg.Id == request.BlockGroupId);
+
+        return blockGroupExists
+            ? Success<BaseError, Unit>(Unit.Default)
+            : BaseError.New("Block group does not exist");
+    }
 
     private static async Task<Validation<BaseError, string>> ValidateBlockName(
         TvContext dbContext,

ErsatzTV.Application/Scheduling/Commands/CreateDecoHandler.cs

@@ -25,8 +25,12 @@ public class CreateDecoHandler(IDbContextFactory<TvContext> dbContextFactory)
         return Mapper.ProjectToViewModel(deco);
     }
 
-    private static async Task<Validation<BaseError, Deco>> Validate(TvContext dbContext, CreateDeco request) =>
-        await ValidateDecoName(dbContext, request).MapT(name => new Deco
+    private static async Task<Validation<BaseError, Deco>> Validate(TvContext dbContext, CreateDeco request)
+    {
+        Validation<BaseError, Unit> decoGroupValidation = await ValidateDecoGroupExists(dbContext, request);
+        Validation<BaseError, string> nameValidation = await ValidateDecoName(dbContext, request);
+
+        return (decoGroupValidation, nameValidation).Apply((_, name) => new Deco
         {
             DecoGroupId = request.DecoGroupId,
             Name = name,
@@ -34,6 +38,18 @@ public class CreateDecoHandler(IDbContextFactory<TvContext> dbContextFactory)
             DecoWatermarks = [],
             DecoGraphicsElements = []
         });
+    }
+
+    private static async Task<Validation<BaseError, Unit>> ValidateDecoGroupExists(
+        TvContext dbContext,
+        CreateDeco request)
+    {
+        bool decoGroupExists = await dbContext.DecoGroups.AnyAsync(dg => dg.Id == request.DecoGroupId);
+
+        return decoGroupExists
+            ? Success<BaseError, Unit>(Unit.Default)
+            : BaseError.New("Deco group does not exist");
+    }
 
     private static async Task<Validation<BaseError, string>> ValidateDecoName(
         TvContext dbContext,

ErsatzTV.Application/Scheduling/Commands/CreateDecoTemplateHandler.cs

@@ -27,12 +27,30 @@ public class CreateDecoTemplateHandler(IDbContextFactory<TvContext> dbContextFac
 
     private static async Task<Validation<BaseError, DecoTemplate>> Validate(
         TvContext dbContext,
-        CreateDecoTemplate request) =>
-        await ValidateDecoTemplateName(dbContext, request).MapT(name => new DecoTemplate
+        CreateDecoTemplate request)
+    {
+        Validation<BaseError, Unit> decoTemplateGroupValidation =
+            await ValidateDecoTemplateGroupExists(dbContext, request);
+        Validation<BaseError, string> nameValidation = await ValidateDecoTemplateName(dbContext, request);
+
+        return (decoTemplateGroupValidation, nameValidation).Apply((_, name) => new DecoTemplate
         {
             DecoTemplateGroupId = request.DecoTemplateGroupId,
             Name = name
         });
+    }
+
+    private static async Task<Validation<BaseError, Unit>> ValidateDecoTemplateGroupExists(
+        TvContext dbContext,
+        CreateDecoTemplate request)
+    {
+        bool decoTemplateGroupExists =
+            await dbContext.DecoTemplateGroups.AnyAsync(dtg => dtg.Id == request.DecoTemplateGroupId);
+
+        return decoTemplateGroupExists
+            ? Success<BaseError, Unit>(Unit.Default)
+            : BaseError.New("Deco template group does not exist");
+    }
 
     private static async Task<Validation<BaseError, string>> ValidateDecoTemplateName(
         TvContext dbContext,

ErsatzTV.Application/Scheduling/Commands/CreateTemplateHandler.cs

@@ -25,12 +25,28 @@ public class CreateTemplateHandler(IDbContextFactory<TvContext> dbContextFactory
         return Mapper.ProjectToViewModel(template);
     }
 
-    private static async Task<Validation<BaseError, Template>> Validate(TvContext dbContext, CreateTemplate request) =>
-        await ValidateTemplateName(dbContext, request).MapT(name => new Template
+    private static async Task<Validation<BaseError, Template>> Validate(TvContext dbContext, CreateTemplate request)
+    {
+        Validation<BaseError, Unit> templateGroupValidation = await ValidateTemplateGroupExists(dbContext, request);
+        Validation<BaseError, string> nameValidation = await ValidateTemplateName(dbContext, request);
+
+        return (templateGroupValidation, nameValidation).Apply((_, name) => new Template
         {
             TemplateGroupId = request.TemplateGroupId,
             Name = name
         });
+    }
+
+    private static async Task<Validation<BaseError, Unit>> ValidateTemplateGroupExists(
+        TvContext dbContext,
+        CreateTemplate request)
+    {
+        bool templateGroupExists = await dbContext.TemplateGroups.AnyAsync(tg => tg.Id == request.TemplateGroupId);
+
+        return templateGroupExists
+            ? Success<BaseError, Unit>(Unit.Default)
+            : BaseError.New("Template group does not exist");
+    }
 
     private static async Task<Validation<BaseError, string>> ValidateTemplateName(
         TvContext dbContext,

ErsatzTV.Application/Scheduling/Commands/ReplaceDecoTemplateItemsHandler.cs

@@ -29,11 +29,7 @@ public class ReplaceDecoTemplateItemsHandler(IDbContextFactory<TvContext> dbCont
 
         dbContext.RemoveRange(decoTemplate.Items);
 
-        // drop items that are invalid
-        decoTemplate.Items = request.Items
-            .Map(i => BuildItem(decoTemplate, i))
-            .Filter(i => i.StartTime < i.EndTime || i.EndTime == TimeSpan.Zero)
-            .ToList();
+        decoTemplate.Items = request.Items.Map(i => BuildItem(decoTemplate, i)).ToList();
 
         await dbContext.SaveChangesAsync(cancellationToken);
 
@@ -66,7 +62,78 @@ public class ReplaceDecoTemplateItemsHandler(IDbContextFactory<TvContext> dbCont
         ReplaceDecoTemplateItems request,
         CancellationToken cancellationToken) =>
         DecoTemplateMustExist(dbContext, request.DecoTemplateId, cancellationToken)
-            .BindT(decoTemplate => DecoTemplateNameMustBeValid(dbContext, decoTemplate, request));
+            .BindT(decoTemplate => DecoTemplateNameMustBeValid(dbContext, decoTemplate, request))
+            .BindT(decoTemplate => DecoTemplateItemsMustBeValid(dbContext, decoTemplate, request));
+
+    // Hardening (deliberate deviation from the original handler): rather than silently filtering out
+    // invalid items (unknown DecoId, StartTime >= EndTime, or overlapping ranges) - the same silent-drop
+    // and silent-overlap bug class fixed for ReplaceTemplateItemsHandler in #144 S2 - reject the whole
+    // request with a 422 so the caller knows exactly what is wrong. EndTime == TimeSpan.Zero means
+    // "end of day" (24:00) and is treated as such for both the ordering and overlap checks.
+    private static async Task<Validation<BaseError, DecoTemplate>> DecoTemplateItemsMustBeValid(
+        TvContext dbContext,
+        DecoTemplate decoTemplate,
+        ReplaceDecoTemplateItems request)
+    {
+        var allDecoIds = request.Items.Map(i => i.DecoId).Distinct().ToList();
+
+        Dictionary<int, Deco> allDecos = await dbContext.Decos
+            .AsNoTracking()
+            .Filter(d => allDecoIds.Contains(d.Id))
+            .ToListAsync()
+            .Map(list => list.ToDictionary(d => d.Id, d => d));
+
+        var missingDecoIds = allDecoIds.Filter(id => !allDecos.ContainsKey(id)).ToList();
+        if (missingDecoIds.Count > 0)
+        {
+            return BaseError.New($"[DecoId] {missingDecoIds.Head()} does not exist.");
+        }
+
+        var itemsWithEffectiveEnd = request.Items
+            .Map(i => new DecoTemplateItemRange(
+                i.DecoId,
+                i.StartTime,
+                i.EndTime,
+                i.EndTime == TimeSpan.Zero ? TimeSpan.FromHours(24) : i.EndTime))
+            .ToList();
+
+        foreach (DecoTemplateItemRange item in itemsWithEffectiveEnd)
+        {
+            if (item.StartTime < TimeSpan.Zero || item.StartTime >= TimeSpan.FromHours(24) ||
+                item.EndTime < TimeSpan.Zero || item.EndTime > TimeSpan.FromHours(24))
+            {
+                return BaseError.New(
+                    $"Deco from {item.StartTime} to {item.EndTime} must be within a single day (00:00 to 24:00)");
+            }
+
+            if (item.StartTime >= item.EffectiveEndTime)
+            {
+                return BaseError.New(
+                    $"Deco from {item.StartTime} to {item.EndTime} must start before it ends");
+            }
+        }
+
+        foreach (DecoTemplateItemRange item in itemsWithEffectiveEnd)
+        {
+            foreach (DecoTemplateItemRange otherItem in itemsWithEffectiveEnd)
+            {
+                if (item == otherItem)
+                {
+                    continue;
+                }
+
+                if (item.StartTime < otherItem.EffectiveEndTime && otherItem.StartTime < item.EffectiveEndTime)
+                {
+                    return BaseError.New(
+                        $"Deco from {item.StartTime} to {item.EndTime} intersects deco from {otherItem.StartTime} to {otherItem.EndTime}");
+                }
+            }
+        }
+
+        return decoTemplate;
+    }
+
+    private sealed record DecoTemplateItemRange(int DecoId, TimeSpan StartTime, TimeSpan EndTime, TimeSpan EffectiveEndTime);
 
     private static Task<Validation<BaseError, DecoTemplate>> DecoTemplateMustExist(
         TvContext dbContext,

ErsatzTV.Application/Scheduling/Commands/ReplaceTemplateItemsHandler.cs

@@ -76,16 +76,29 @@ public class ReplaceTemplateItemsHandler(IDbContextFactory<TvContext> dbContextF
             .ToListAsync()
             .Map(list => list.ToDictionary(b => b.Id, b => b));
 
+        var missingBlockIds = allBlockIds.Filter(id => !allBlocks.ContainsKey(id)).ToList();
+        if (missingBlockIds.Count > 0)
+        {
+            return BaseError.New($"[BlockId] {missingBlockIds.Head()} does not exist.");
+        }
+
         var allTemplateItems = request.Items.Map(i =>
             {
                 Block block = allBlocks[i.BlockId];
-                return new BlockTemplateItem(
-                    i.BlockId,
-                    i.StartTime,
-                    i.StartTime + TimeSpan.FromMinutes(block.Minutes));
+                var endTime = i.StartTime + TimeSpan.FromMinutes(block.Minutes);
+                return new BlockTemplateItem(i.BlockId, i.StartTime, endTime);
             })
             .ToList();
 
+        foreach (BlockTemplateItem item in allTemplateItems)
+        {
+            if (item.EndTime > TimeSpan.FromHours(24))
+            {
+                return BaseError.New(
+                    $"Block from {item.StartTime} to {item.EndTime} crosses midnight, which is not supported");
+            }
+        }
+
         foreach (BlockTemplateItem item in allTemplateItems)
         {
             foreach (BlockTemplateItem otherItem in allTemplateItems)

ErsatzTV.Application/Scheduling/Commands/UpdateDecoHandler.cs

@@ -97,6 +97,7 @@ public class UpdateDecoHandler(IDbContextFactory<TvContext> dbContextFactory)
             {
                 ex.CollectionType = toUpdate.CollectionType;
                 ex.CollectionId = toUpdate.CollectionId;
+                ex.MediaItemId = toUpdate.MediaItemId;
                 ex.MultiCollectionId = toUpdate.MultiCollectionId;
                 ex.SmartCollectionId = toUpdate.SmartCollectionId;
                 ex.PlaylistId = toUpdate.PlaylistId;
@@ -111,6 +112,7 @@ public class UpdateDecoHandler(IDbContextFactory<TvContext> dbContextFactory)
                 DecoId = existing.Id,
                 CollectionType = add.CollectionType,
                 CollectionId = add.CollectionId,
+                MediaItemId = add.MediaItemId,
                 MultiCollectionId = add.MultiCollectionId,
                 SmartCollectionId = add.SmartCollectionId,
                 PlaylistId = add.PlaylistId,

ErsatzTV.Application/Search/Queries/GetSearchResults.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Search;
+
+namespace ErsatzTV.Application.Search;
+
+public record GetSearchResults(string Query, int PageSize) : IRequest<SearchResultsResponseModel>;

ErsatzTV.Application/Search/Queries/GetSearchResultsHandler.cs

@@ -0,0 +1,65 @@
+using ErsatzTV.Application.LibraryBrowse;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Api.Search;
+using MediatR;
+
+namespace ErsatzTV.Application.Search;
+
+// Fans out to the shared library-browse query once per media kind (mirroring the legacy Search.razor page,
+// which sends one `type:{kind} AND ({query})` query per kind). Reusing GetLibraryBrowseItems keeps hydration,
+// artwork resolution and the response shape identical to /api/library/browse. Raw Lucene queries pass through
+// unchanged, so state filters such as `state:FileNotFound` (the Trash screen) work here too.
+public class GetSearchResultsHandler(IMediator mediator)
+    : IRequestHandler<GetSearchResults, SearchResultsResponseModel>
+{
+    public async Task<SearchResultsResponseModel> Handle(
+        GetSearchResults request,
+        CancellationToken cancellationToken)
+    {
+        async Task<SearchResultGroupResponseModel> ForKind(LibraryBrowseMediaType kind)
+        {
+            PagedLibraryBrowseItemsResponseModel paged = await mediator.Send(
+                new GetLibraryBrowseItems(request.Query, null, kind, 0, request.PageSize),
+                cancellationToken);
+            return new SearchResultGroupResponseModel(paged.TotalCount, paged.Page);
+        }
+
+        // Each ForKind call sends through IMediator to GetLibraryBrowseItemsHandler, which creates its
+        // own TvContext per invocation via IDbContextFactory<TvContext> (never shares one across calls),
+        // so these are safe to run concurrently.
+        Task<SearchResultGroupResponseModel> movies = ForKind(LibraryBrowseMediaType.Movie);
+        Task<SearchResultGroupResponseModel> shows = ForKind(LibraryBrowseMediaType.TelevisionShow);
+        Task<SearchResultGroupResponseModel> seasons = ForKind(LibraryBrowseMediaType.TelevisionSeason);
+        Task<SearchResultGroupResponseModel> artists = ForKind(LibraryBrowseMediaType.Artist);
+        Task<SearchResultGroupResponseModel> episodes = ForKind(LibraryBrowseMediaType.Episode);
+        Task<SearchResultGroupResponseModel> musicVideos = ForKind(LibraryBrowseMediaType.MusicVideo);
+        Task<SearchResultGroupResponseModel> songs = ForKind(LibraryBrowseMediaType.Song);
+        Task<SearchResultGroupResponseModel> otherVideos = ForKind(LibraryBrowseMediaType.OtherVideo);
+        Task<SearchResultGroupResponseModel> images = ForKind(LibraryBrowseMediaType.Image);
+        Task<SearchResultGroupResponseModel> remoteStreams = ForKind(LibraryBrowseMediaType.RemoteStream);
+
+        await Task.WhenAll(
+            movies,
+            shows,
+            seasons,
+            artists,
+            episodes,
+            musicVideos,
+            songs,
+            otherVideos,
+            images,
+            remoteStreams);
+
+        return new SearchResultsResponseModel(
+            movies.Result,
+            shows.Result,
+            seasons.Result,
+            artists.Result,
+            episodes.Result,
+            musicVideos.Result,
+            songs.Result,
+            otherVideos.Result,
+            images.Result,
+            remoteStreams.Result);
+    }
+}

ErsatzTV.Application/Troubleshooting/Queries/DecodePlayoutHistoryHandler.cs

@@ -1,8 +1,5 @@
-using ErsatzTV.Core.Domain;
 using ErsatzTV.Infrastructure.Data;
-using ErsatzTV.Infrastructure.Extensions;
 using Microsoft.EntityFrameworkCore;
-using Newtonsoft.Json;
 
 namespace ErsatzTV.Application.Troubleshooting.Queries;
 
@@ -15,83 +12,10 @@ public class DecodePlayoutHistoryHandler(IDbContextFactory<TvContext> dbContextF
     {
         await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
 
-        var decodedKey = JsonConvert.DeserializeObject<BlockItemHistoryKey>(request.PlayoutHistory.Key);
-
-        PlaybackOrder playbackOrder = decodedKey.PlaybackOrder ?? PlaybackOrder.None;
-        CollectionType collectionType = decodedKey.CollectionType ?? CollectionType.Collection;
-
-        string name = string.Empty;
-
-        switch (collectionType)
-        {
-            case CollectionType.Collection:
-                name = await dbContext.Collections
-                    .AsNoTracking()
-                    .Where(c => c.Id == (decodedKey.CollectionId ?? 0))
-                    .Map(c => c.Name)
-                    .FirstOrDefaultAsync(cancellationToken);
-                break;
-            case CollectionType.SmartCollection:
-                name = await dbContext.SmartCollections
-                    .AsNoTracking()
-                    .Where(c => c.Id == (decodedKey.SmartCollectionId ?? 0))
-                    .Map(c => c.Name)
-                    .FirstOrDefaultAsync(cancellationToken);
-                break;
-        }
-
-        string mediaItemType = string.Empty;
-        string mediaItemTitle = string.Empty;
-
-        Details details = JsonConvert.DeserializeObject<Details>(request.PlayoutHistory.Details);
-        if (details?.MediaItemId != null)
-        {
-            Option<MediaItem> maybeMediaItem = await dbContext.MediaItems
-                .AsNoTracking()
-                .Include(i => i.LibraryPath)
-                .ThenInclude(lp => lp.Library)
-                .ThenInclude(l => l.MediaSource)
-                .Include(i => (i as Movie).MovieMetadata)
-                .Include(i => (i as Episode).EpisodeMetadata)
-                .Include(i => (i as Episode).Season)
-                .ThenInclude(s => s.Show)
-                .ThenInclude(s => s.ShowMetadata)
-                .Include(i => (i as OtherVideo).OtherVideoMetadata)
-                .Include(i => (i as Image).ImageMetadata)
-                .Include(i => (i as RemoteStream).RemoteStreamMetadata)
-                .Include(i => (i as Song).SongMetadata)
-                .Include(i => (i as MusicVideo).MusicVideoMetadata)
-                .Include(i => (i as MusicVideo).Artist)
-                .ThenInclude(a => a.ArtistMetadata)
-                .SelectOneAsync(i => i.Id, i => i.Id == details.MediaItemId, cancellationToken);
-
-            foreach (var mediaItem in maybeMediaItem)
-            {
-                mediaItemType = mediaItem switch
-                {
-                    Episode => "Episode",
-                    Movie => "Movie",
-                    MusicVideo => "Music Video",
-                    OtherVideo => "Other Video",
-                    Song => "Song",
-                    Image => "Image",
-                    RemoteStream => "Remote Stream",
-                    _ => $"Unknown ({mediaItem.GetType().Name})"
-                };
-
-                mediaItemTitle = Playouts.Mapper.GetDisplayTitle(mediaItem, Option<string>.None);
-            }
-        }
-
-        return new PlayoutHistoryDetailsViewModel(playbackOrder, collectionType, name, mediaItemType, mediaItemTitle);
+        return await PlayoutHistoryDecoder.Decode(
+            dbContext,
+            request.PlayoutHistory.Key,
+            request.PlayoutHistory.Details,
+            cancellationToken);
     }
-
-    private sealed record BlockItemHistoryKey(
-        int? BlockId,
-        PlaybackOrder? PlaybackOrder,
-        CollectionType? CollectionType,
-        int? CollectionId,
-        int? SmartCollectionId);
-
-    private sealed record Details(int? MediaItemId);
 }

ErsatzTV.Application/Troubleshooting/Queries/GetPlayoutHistoryDetails.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.Troubleshooting.Queries;
+
+public record GetPlayoutHistoryDetails(int Id) : IRequest<Either<BaseError, PlayoutHistoryDetailsViewModel>>;

ErsatzTV.Application/Troubleshooting/Queries/GetPlayoutHistoryDetailsHandler.cs

@@ -0,0 +1,42 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain.Scheduling;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Troubleshooting.Queries;
+
+public class GetPlayoutHistoryDetailsHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetPlayoutHistoryDetails, Either<BaseError, PlayoutHistoryDetailsViewModel>>
+{
+    public async Task<Either<BaseError, PlayoutHistoryDetailsViewModel>> Handle(
+        GetPlayoutHistoryDetails request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        Option<PlayoutHistory> maybeHistory = await dbContext.PlayoutHistory
+            .AsNoTracking()
+            .SelectOneAsync(ph => ph.Id, ph => ph.Id == request.Id, cancellationToken);
+
+        foreach (PlayoutHistory history in maybeHistory)
+        {
+            try
+            {
+                return await PlayoutHistoryDecoder.Decode(
+                    dbContext,
+                    history.Key,
+                    history.Details,
+                    cancellationToken);
+            }
+            catch (Exception ex)
+            {
+                // old/corrupt rows may carry malformed Key/Details JSON; surface a 422 rather than a 500
+                return BaseError.New($"Unable to decode playout history: {ex.Message}");
+            }
+        }
+
+        return new NotFoundError($"Playout history {request.Id} does not exist");
+    }
+}

ErsatzTV.Application/Troubleshooting/Queries/PlayoutHistoryDecoder.cs

@@ -0,0 +1,99 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+using Newtonsoft.Json;
+
+namespace ErsatzTV.Application.Troubleshooting.Queries;
+
+// Shared decode logic for a single PlayoutHistory row's Key/Details JSON. Both
+// DecodePlayoutHistoryHandler (Blazor) and GetPlayoutHistoryDetailsHandler (API) use this
+// so the collection/media-item lookup lives in exactly one place.
+internal static class PlayoutHistoryDecoder
+{
+    public static async Task<PlayoutHistoryDetailsViewModel> Decode(
+        TvContext dbContext,
+        string key,
+        string details,
+        CancellationToken cancellationToken)
+    {
+        var decodedKey = JsonConvert.DeserializeObject<BlockItemHistoryKey>(key);
+
+        PlaybackOrder playbackOrder = decodedKey.PlaybackOrder ?? PlaybackOrder.None;
+        CollectionType collectionType = decodedKey.CollectionType ?? CollectionType.Collection;
+
+        string name = string.Empty;
+
+        switch (collectionType)
+        {
+            case CollectionType.Collection:
+                name = await dbContext.Collections
+                    .AsNoTracking()
+                    .Where(c => c.Id == (decodedKey.CollectionId ?? 0))
+                    .Map(c => c.Name)
+                    .FirstOrDefaultAsync(cancellationToken);
+                break;
+            case CollectionType.SmartCollection:
+                name = await dbContext.SmartCollections
+                    .AsNoTracking()
+                    .Where(c => c.Id == (decodedKey.SmartCollectionId ?? 0))
+                    .Map(c => c.Name)
+                    .FirstOrDefaultAsync(cancellationToken);
+                break;
+        }
+
+        string mediaItemType = string.Empty;
+        string mediaItemTitle = string.Empty;
+
+        Details decodedDetails = JsonConvert.DeserializeObject<Details>(details);
+        if (decodedDetails?.MediaItemId != null)
+        {
+            Option<MediaItem> maybeMediaItem = await dbContext.MediaItems
+                .AsNoTracking()
+                .Include(i => i.LibraryPath)
+                .ThenInclude(lp => lp.Library)
+                .ThenInclude(l => l.MediaSource)
+                .Include(i => (i as Movie).MovieMetadata)
+                .Include(i => (i as Episode).EpisodeMetadata)
+                .Include(i => (i as Episode).Season)
+                .ThenInclude(s => s.Show)
+                .ThenInclude(s => s.ShowMetadata)
+                .Include(i => (i as OtherVideo).OtherVideoMetadata)
+                .Include(i => (i as Image).ImageMetadata)
+                .Include(i => (i as RemoteStream).RemoteStreamMetadata)
+                .Include(i => (i as Song).SongMetadata)
+                .Include(i => (i as MusicVideo).MusicVideoMetadata)
+                .Include(i => (i as MusicVideo).Artist)
+                .ThenInclude(a => a.ArtistMetadata)
+                .SelectOneAsync(i => i.Id, i => i.Id == decodedDetails.MediaItemId, cancellationToken);
+
+            foreach (var mediaItem in maybeMediaItem)
+            {
+                mediaItemType = mediaItem switch
+                {
+                    Episode => "Episode",
+                    Movie => "Movie",
+                    MusicVideo => "Music Video",
+                    OtherVideo => "Other Video",
+                    Song => "Song",
+                    Image => "Image",
+                    RemoteStream => "Remote Stream",
+                    _ => $"Unknown ({mediaItem.GetType().Name})"
+                };
+
+                mediaItemTitle = Playouts.Mapper.GetDisplayTitle(mediaItem, Option<string>.None);
+            }
+        }
+
+        return new PlayoutHistoryDetailsViewModel(playbackOrder, collectionType, name, mediaItemType, mediaItemTitle);
+    }
+
+    private sealed record BlockItemHistoryKey(
+        int? BlockId,
+        PlaybackOrder? PlaybackOrder,
+        CollectionType? CollectionType,
+        int? CollectionId,
+        int? SmartCollectionId);
+
+    private sealed record Details(int? MediaItemId);
+}

ErsatzTV.Application/Troubleshooting/Queries/ValidateSequentialSchedule.cs

@@ -0,0 +1,3 @@
+namespace ErsatzTV.Application.Troubleshooting.Queries;
+
+public record ValidateSequentialSchedule(string Yaml, bool IsImport) : IRequest<ValidateSequentialScheduleViewModel>;

ErsatzTV.Application/Troubleshooting/Queries/ValidateSequentialScheduleHandler.cs

@@ -0,0 +1,25 @@
+using ErsatzTV.Core.Interfaces.Scheduling;
+
+namespace ErsatzTV.Application.Troubleshooting.Queries;
+
+public class ValidateSequentialScheduleHandler(ISequentialScheduleValidator validator)
+    : IRequestHandler<ValidateSequentialSchedule, ValidateSequentialScheduleViewModel>
+{
+    public async Task<ValidateSequentialScheduleViewModel> Handle(
+        ValidateSequentialSchedule request,
+        CancellationToken cancellationToken)
+    {
+        try
+        {
+            // ToJson runs first and can throw on malformed YAML (GetValidationMessages catches its
+            // own exceptions internally); mirrors the Blazor YamlValidator ordering.
+            string json = validator.ToJson(request.Yaml);
+            IList<string> messages = await validator.GetValidationMessages(request.Yaml, request.IsImport);
+            return new ValidateSequentialScheduleViewModel(messages.Count == 0, messages.ToList(), json);
+        }
+        catch (Exception ex)
+        {
+            return new ValidateSequentialScheduleViewModel(false, [ex.Message], string.Empty);
+        }
+    }
+}

ErsatzTV.Application/Troubleshooting/ValidateSequentialScheduleViewModel.cs

@@ -0,0 +1,3 @@
+namespace ErsatzTV.Application.Troubleshooting;
+
+public record ValidateSequentialScheduleViewModel(bool IsValid, List<string> Messages, string Json);

ErsatzTV.Application/Watermarks/Commands/DeleteWatermarkHandler.cs

@@ -1,5 +1,6 @@
-using ErsatzTV.Core;
+using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Core.Interfaces.Search;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
@@ -23,11 +24,14 @@ public class DeleteWatermarkHandler : IRequestHandler<DeleteWatermark, Either<Ba
         CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-        Validation<BaseError, ChannelWatermark> validation = await WatermarkMustExist(
-            dbContext,
-            request,
-            cancellationToken);
-        return await validation.Apply(p => DoDeletion(dbContext, p));
+        Option<ChannelWatermark> maybeWatermark = await WatermarkMustExist(dbContext, request, cancellationToken);
+
+        // must-exist maps to a NotFoundError Either directly (not via Validation, which
+        // aggregates errors and loses the subtype the API layer maps to 404)
+        return await maybeWatermark.Match(
+            Some: watermark => DoDeletion(dbContext, watermark).Map(Right<BaseError, Unit>),
+            None: () => Task.FromResult<Either<BaseError, Unit>>(
+                new NotFoundError($"Watermark {request.WatermarkId} does not exist")));
     }
 
     private async Task<Unit> DoDeletion(TvContext dbContext, ChannelWatermark watermark)
@@ -40,11 +44,10 @@ public class DeleteWatermarkHandler : IRequestHandler<DeleteWatermark, Either<Ba
         return Unit.Default;
     }
 
-    private static Task<Validation<BaseError, ChannelWatermark>> WatermarkMustExist(
+    private static Task<Option<ChannelWatermark>> WatermarkMustExist(
         TvContext dbContext,
         DeleteWatermark request,
         CancellationToken cancellationToken) =>
         dbContext.ChannelWatermarks
-            .SelectOneAsync(p => p.Id, p => p.Id == request.WatermarkId, cancellationToken)
-            .Map(o => o.ToValidation<BaseError>($"Watermark {request.WatermarkId} does not exist"));
+            .SelectOneAsync(p => p.Id, p => p.Id == request.WatermarkId, cancellationToken);
 }

ErsatzTV.Application/Watermarks/Commands/UpdateWatermarkHandler.cs

@@ -1,5 +1,6 @@
-using ErsatzTV.Core;
+using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
 using ErsatzTV.Core.Interfaces.Search;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
@@ -23,8 +24,18 @@ public class UpdateWatermarkHandler : IRequestHandler<UpdateWatermark, Either<Ba
         CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-        Validation<BaseError, ChannelWatermark> validation = await Validate(dbContext, request, cancellationToken);
-        return await validation.Apply(p => ApplyUpdateRequest(dbContext, p, request));
+        Option<ChannelWatermark> maybeWatermark = await WatermarkMustExist(dbContext, request, cancellationToken);
+
+        // must-exist maps to a NotFoundError Either directly (not via Validation, which
+        // aggregates errors and loses the subtype the API layer maps to 404)
+        return await maybeWatermark.Match(
+            Some: async watermark =>
+            {
+                Validation<BaseError, string> validation = await ValidateName(dbContext, request);
+                return await validation.Apply((string _) => ApplyUpdateRequest(dbContext, watermark, request));
+            },
+            None: () => Task.FromResult<Either<BaseError, UpdateWatermarkResult>>(
+                new NotFoundError("Watermark does not exist.")));
     }
 
     private async Task<UpdateWatermarkResult> ApplyUpdateRequest(
@@ -61,20 +72,12 @@ public class UpdateWatermarkHandler : IRequestHandler<UpdateWatermark, Either<Ba
         return new UpdateWatermarkResult(p.Id);
     }
 
-    private static async Task<Validation<BaseError, ChannelWatermark>> Validate(
-        TvContext dbContext,
-        UpdateWatermark request,
-        CancellationToken cancellationToken) =>
-        (await WatermarkMustExist(dbContext, request, cancellationToken), await ValidateName(dbContext, request))
-        .Apply((watermark, _) => watermark);
-
-    private static Task<Validation<BaseError, ChannelWatermark>> WatermarkMustExist(
+    private static Task<Option<ChannelWatermark>> WatermarkMustExist(
         TvContext dbContext,
         UpdateWatermark updateWatermark,
         CancellationToken cancellationToken) =>
         dbContext.ChannelWatermarks
-            .SelectOneAsync(p => p.Id, p => p.Id == updateWatermark.Id, cancellationToken)
-            .Map(o => o.ToValidation<BaseError>("Watermark does not exist."));
+            .SelectOneAsync(p => p.Id, p => p.Id == updateWatermark.Id, cancellationToken);
 
     private static async Task<Validation<BaseError, string>> ValidateName(
         TvContext dbContext,

ErsatzTV.Application/Watermarks/Mapper.cs

@@ -1,10 +1,34 @@
 using ErsatzTV.Application.Artworks;
+using ErsatzTV.Core.Api.Watermarks;
 using ErsatzTV.Core.Domain;
 
 namespace ErsatzTV.Application.Watermarks;
 
 internal static class Mapper
 {
+    internal static WatermarkResponseModel ProjectToResponseModel(ChannelWatermark watermark) =>
+        new(watermark.Id, watermark.Name);
+
+    internal static WatermarkFullResponseModel ProjectToFullResponseModel(ChannelWatermark watermark) =>
+        new(
+            watermark.Id,
+            watermark.Name,
+            watermark.Mode,
+            watermark.ImageSource,
+            watermark.Image,
+            watermark.OriginalContentType,
+            watermark.Location,
+            watermark.Size,
+            watermark.WidthPercent,
+            watermark.HorizontalMarginPercent,
+            watermark.VerticalMarginPercent,
+            watermark.FrequencyMinutes,
+            watermark.DurationSeconds,
+            watermark.Opacity,
+            watermark.OpacityExpression,
+            watermark.ZIndex,
+            watermark.PlaceWithinSourceContent);
+
     public static WatermarkViewModel ProjectToViewModel(ChannelWatermark watermark) =>
         new(
             watermark.Id,

ErsatzTV.Application/Watermarks/Queries/GetAllWatermarksForApi.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.Watermarks;
+
+namespace ErsatzTV.Application.Watermarks;
+
+public record GetAllWatermarksForApi : IRequest<List<WatermarkResponseModel>>;

ErsatzTV.Application/Watermarks/Queries/GetAllWatermarksForApiHandler.cs

@@ -0,0 +1,22 @@
+using ErsatzTV.Core.Api.Watermarks;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Watermarks.Mapper;
+
+namespace ErsatzTV.Application.Watermarks;
+
+public class GetAllWatermarksForApiHandler(IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetAllWatermarksForApi, List<WatermarkResponseModel>>
+{
+    public async Task<List<WatermarkResponseModel>> Handle(
+        GetAllWatermarksForApi request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        List<ChannelWatermark> watermarks = await dbContext.ChannelWatermarks
+            .AsNoTracking()
+            .ToListAsync(cancellationToken);
+        return watermarks.Map(ProjectToResponseModel).ToList();
+    }
+}