# Installer: Download-Mode + Gitea Releases — Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Rewrite `ClaudeDo.Installer` so it downloads prebuilt App + Worker binaries from a Gitea release on `git.kuns.dev/releases/ClaudeDo` instead of building from source, with a three-way launch flow (fresh install / update / config).

**Architecture:** Fresh install keeps the current wizard (minus the three `dotnet publish`/deploy steps, plus a new `DownloadAndExtractStep`). On every subsequent launch, an async `InstallModeDetector` reads `{InstallDir}/install.json`, hits the Gitea API, and picks between Update mode (short wizard with download) or Config mode (existing `SettingsWindow`, now with Repair + Uninstall buttons).

**Tech Stack:** .NET 8 / WPF + CommunityToolkit.Mvvm (existing), `System.Net.Http`, `System.IO.Compression`, `System.Security.Cryptography.SHA256`, `sc.exe` via `ProcessRunner`. xUnit 2.5.3 tests (matching `ClaudeDo.Worker.Tests` conventions — no mocking library, sealed fakes only).

**Branch:** `feat/installer` (already checked out).

**Out of scope (handled elsewhere):**
- `.gitea/workflows/release.yml` — being written by Claude on the VPS.
- Actually publishing releases / runner setup / signing.
- Spec doc — already at `docs/superpowers/specs/2026-04-15-installer-download-mode-design.md`.

---

## File Structure Overview

**New production files:**

| Path | Responsibility |
|------|----------------|
| `src/ClaudeDo.Installer/Core/InstallManifest.cs` | `install.json` record + read/write helpers |
| `src/ClaudeDo.Installer/Core/ChecksumVerifier.cs` | SHA256 compute + checksum-file parse |
| `src/ClaudeDo.Installer/Core/IReleaseClient.cs` | Interface for Gitea release queries (DI seam) |
| `src/ClaudeDo.Installer/Core/ReleaseClient.cs` | Gitea API calls + asset downloads |
| `src/ClaudeDo.Installer/Core/InstallModeDetector.cs` | Async: reads manifest + queries API, returns `DetectedState` |
| `src/ClaudeDo.Installer/Steps/StopServiceStep.cs` | `sc stop ClaudeDoWorker` with timeout |
| `src/ClaudeDo.Installer/Steps/StartServiceStep.cs` | `sc start ClaudeDoWorker` |
| `src/ClaudeDo.Installer/Steps/DownloadAndExtractStep.cs` | API → download → verify → extract into `{InstallDir}` |
| `src/ClaudeDo.Installer/Steps/WriteInstallManifestStep.cs` | Writes `install.json` at the end of install/update |

**Files modified:**

| Path | Why |
|------|-----|
| `src/ClaudeDo.Installer/Core/InstallerMode.cs` | Rename enum values, replace `ModeDetector` with async flow |
| `src/ClaudeDo.Installer/Core/InstallContext.cs` | Drop `SourceDirectory`, add `InstallerVersion`, `InstalledVersion`, `LatestVersion`, `Mode` |
| `src/ClaudeDo.Installer/App.xaml.cs` | Async mode detection at startup; register new services/steps; pick window per mode |
| `src/ClaudeDo.Installer/Pages/WelcomePage/WelcomePageViewModel.cs` + `.xaml` | Remove source-dir UI; show current/target version for update mode |
| `src/ClaudeDo.Installer/Views/SettingsViewModel.cs` + `SettingsWindow.xaml` | Add Repair + Uninstall commands/buttons |
| `src/ClaudeDo.Installer/ClaudeDo.Installer.csproj` | Publish properties for single-file self-contained |
| `ClaudeDo.slnx` | Add new test project |

**Files deleted:**

| Path | Why |
|------|-----|
| `src/ClaudeDo.Installer/Steps/PublishAppStep.cs` | Replaced by `DownloadAndExtractStep` |
| `src/ClaudeDo.Installer/Steps/PublishWorkerStep.cs` | Same |
| `src/ClaudeDo.Installer/Steps/DeployBinariesStep.cs` | Same |

**New test project:** `tests/ClaudeDo.Installer.Tests/` (xUnit, targets `net8.0-windows` so it can reference the WPF installer project).

---

## Task 1: Scaffold `ClaudeDo.Installer.Tests` project

**Files:**
- Create: `tests/ClaudeDo.Installer.Tests/ClaudeDo.Installer.Tests.csproj`
- Create: `tests/ClaudeDo.Installer.Tests/FakeHttpMessageHandler.cs`
- Modify: `ClaudeDo.slnx`

- [ ] **Step 1: Create the test project file**

Create `tests/ClaudeDo.Installer.Tests/ClaudeDo.Installer.Tests.csproj`:

```xml
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0-windows</TargetFramework>
    <UseWPF>true</UseWPF>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <IsPackable>false</IsPackable>
    <IsTestProject>true</IsTestProject>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="coverlet.collector" Version="6.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
    <PackageReference Include="xunit" Version="2.5.3" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
  </ItemGroup>

  <ItemGroup>
    <Using Include="Xunit" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\..\src\ClaudeDo.Installer\ClaudeDo.Installer.csproj" />
  </ItemGroup>

</Project>
```

Note: `net8.0-windows` + `UseWPF=true` is required because the installer itself is a WPF project; referencing it from the test project means the test project must use the same TFM flavor.

- [ ] **Step 2: Add a reusable `FakeHttpMessageHandler`**

Create `tests/ClaudeDo.Installer.Tests/FakeHttpMessageHandler.cs`:

```csharp
using System.Net;
using System.Net.Http;

namespace ClaudeDo.Installer.Tests;

internal sealed class FakeHttpMessageHandler : HttpMessageHandler
{
    private readonly Func<HttpRequestMessage, HttpResponseMessage> _handler;

    public FakeHttpMessageHandler(Func<HttpRequestMessage, HttpResponseMessage> handler)
    {
        _handler = handler;
    }

    public FakeHttpMessageHandler(HttpStatusCode status, string body)
        : this(_ => new HttpResponseMessage(status) { Content = new StringContent(body) })
    {
    }

    public List<HttpRequestMessage> Requests { get; } = new();

    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        Requests.Add(request);
        return Task.FromResult(_handler(request));
    }
}
```

- [ ] **Step 3: Register the test project in `ClaudeDo.slnx`**

Modify `ClaudeDo.slnx` by adding one line inside the `/tests/` folder:

```xml
  <Folder Name="/tests/">
    <Project Path="tests/ClaudeDo.Ui.Tests/ClaudeDo.Ui.Tests.csproj" />
    <Project Path="tests/ClaudeDo.Worker.Tests/ClaudeDo.Worker.Tests.csproj" />
    <Project Path="tests/ClaudeDo.Installer.Tests/ClaudeDo.Installer.Tests.csproj" />
  </Folder>
```

- [ ] **Step 4: Verify it builds (no tests yet, so no test-run)**

Run: `dotnet build tests/ClaudeDo.Installer.Tests/ClaudeDo.Installer.Tests.csproj`
Expected: Build succeeds.

- [ ] **Step 5: Commit**

```bash
git add tests/ClaudeDo.Installer.Tests ClaudeDo.slnx
git commit -m "test(installer): scaffold ClaudeDo.Installer.Tests project"
```

---

## Task 2: `InstallManifest` + `InstallManifestStore`

**Files:**
- Create: `src/ClaudeDo.Installer/Core/InstallManifest.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/InstallManifestStoreTests.cs`

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/InstallManifestStoreTests.cs`:

```csharp
using System.IO;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Tests;

public sealed class InstallManifestStoreTests : IDisposable
{
    private readonly string _tempDir;

    public InstallManifestStoreTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), "ClaudeDoInstallerTests-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_tempDir);
    }

    public void Dispose()
    {
        try { Directory.Delete(_tempDir, recursive: true); } catch { /* best effort */ }
    }

    [Fact]
    public void TryRead_ReturnsNull_WhenFileMissing()
    {
        var result = InstallManifestStore.TryRead(_tempDir);
        Assert.Null(result);
    }

    [Fact]
    public void Write_Then_Read_RoundTripsAllFields()
    {
        var manifest = new InstallManifest(
            Version: "0.2.0",
            InstallDir: _tempDir,
            WorkerDir: Path.Combine(_tempDir, "worker"),
            InstalledAt: new DateTimeOffset(2026, 4, 15, 12, 34, 56, TimeSpan.Zero));

        InstallManifestStore.Write(_tempDir, manifest);

        var round = InstallManifestStore.TryRead(_tempDir);
        Assert.NotNull(round);
        Assert.Equal("0.2.0", round!.Version);
        Assert.Equal(manifest.InstallDir, round.InstallDir);
        Assert.Equal(manifest.WorkerDir, round.WorkerDir);
        Assert.Equal(manifest.InstalledAt, round.InstalledAt);
    }

    [Fact]
    public void Write_CreatesInstallDir_IfMissing()
    {
        var nested = Path.Combine(_tempDir, "nested");
        Assert.False(Directory.Exists(nested));

        InstallManifestStore.Write(nested, new InstallManifest(
            "0.0.1", nested, Path.Combine(nested, "worker"), DateTimeOffset.UtcNow));

        Assert.True(File.Exists(Path.Combine(nested, "install.json")));
    }

    [Fact]
    public void TryRead_ReturnsNull_WhenJsonMalformed()
    {
        File.WriteAllText(Path.Combine(_tempDir, "install.json"), "{ not json");
        var result = InstallManifestStore.TryRead(_tempDir);
        Assert.Null(result);
    }
}
```

- [ ] **Step 2: Run the test to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter InstallManifestStoreTests`
Expected: FAIL with "type or namespace name 'InstallManifest' could not be found" (or similar compile error).

- [ ] **Step 3: Implement `InstallManifest`**

Create `src/ClaudeDo.Installer/Core/InstallManifest.cs`:

```csharp
using System.IO;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace ClaudeDo.Installer.Core;

public sealed record InstallManifest(
    string Version,
    string InstallDir,
    string WorkerDir,
    DateTimeOffset InstalledAt);

public static class InstallManifestStore
{
    public const string FileName = "install.json";

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        WriteIndented = true,
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
    };

    public static string ManifestPath(string installDir) => Path.Combine(installDir, FileName);

    public static InstallManifest? TryRead(string installDir)
    {
        var path = ManifestPath(installDir);
        if (!File.Exists(path)) return null;

        try
        {
            var json = File.ReadAllText(path);
            return JsonSerializer.Deserialize<InstallManifest>(json, JsonOptions);
        }
        catch
        {
            return null;
        }
    }

    public static void Write(string installDir, InstallManifest manifest)
    {
        Directory.CreateDirectory(installDir);
        var json = JsonSerializer.Serialize(manifest, JsonOptions);
        File.WriteAllText(ManifestPath(installDir), json);
    }
}
```

- [ ] **Step 4: Run the test to verify it passes**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter InstallManifestStoreTests`
Expected: PASS (4 tests).

- [ ] **Step 5: Commit**

```bash
git add src/ClaudeDo.Installer/Core/InstallManifest.cs tests/ClaudeDo.Installer.Tests/InstallManifestStoreTests.cs
git commit -m "feat(installer): add InstallManifest + json-backed store"
```

---

## Task 3: `ChecksumVerifier`

**Files:**
- Create: `src/ClaudeDo.Installer/Core/ChecksumVerifier.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/ChecksumVerifierTests.cs`

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/ChecksumVerifierTests.cs`:

```csharp
using System.IO;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Tests;

public sealed class ChecksumVerifierTests : IDisposable
{
    private readonly string _tempDir;

    public ChecksumVerifierTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), "ClaudeDoChecksum-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_tempDir);
    }

    public void Dispose()
    {
        try { Directory.Delete(_tempDir, recursive: true); } catch { }
    }

    [Fact]
    public void ComputeSha256_KnownVector_EmptyFile()
    {
        // sha256 of empty input = e3b0c442...b855
        var path = Path.Combine(_tempDir, "empty.bin");
        File.WriteAllBytes(path, Array.Empty<byte>());

        var hash = ChecksumVerifier.ComputeSha256(path);

        Assert.Equal("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", hash);
    }

    [Fact]
    public void ComputeSha256_KnownVector_Hello()
    {
        // sha256("hello") = 2cf24dba...a9824
        var path = Path.Combine(_tempDir, "hello.bin");
        File.WriteAllText(path, "hello");

        var hash = ChecksumVerifier.ComputeSha256(path);

        Assert.Equal("2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824", hash);
    }

    [Fact]
    public void Verify_ReturnsTrue_WhenHashMatches()
    {
        var path = Path.Combine(_tempDir, "x.bin");
        File.WriteAllText(path, "hello");

        Assert.True(ChecksumVerifier.Verify(path,
            "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"));
    }

    [Fact]
    public void Verify_IsCaseInsensitive()
    {
        var path = Path.Combine(_tempDir, "x.bin");
        File.WriteAllText(path, "hello");

        Assert.True(ChecksumVerifier.Verify(path,
            "2CF24DBA5FB0A30E26E83B2AC5B9E29E1B161E5C1FA7425E73043362938B9824"));
    }

    [Fact]
    public void Verify_ReturnsFalse_OnMismatch()
    {
        var path = Path.Combine(_tempDir, "x.bin");
        File.WriteAllText(path, "hello");

        Assert.False(ChecksumVerifier.Verify(path, new string('0', 64)));
    }

    [Fact]
    public void ParseChecksumsFile_ReadsTwoLines()
    {
        var content = """
            e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  ClaudeDo-0.2.0-win-x64.zip
            2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824  ClaudeDo.Installer-0.2.0.exe
            """;

        var map = ChecksumVerifier.ParseChecksumsFile(content);

        Assert.Equal(2, map.Count);
        Assert.Equal(
            "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
            map["ClaudeDo-0.2.0-win-x64.zip"]);
        Assert.Equal(
            "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824",
            map["ClaudeDo.Installer-0.2.0.exe"]);
    }

    [Fact]
    public void ParseChecksumsFile_SkipsBlankAndMalformedLines()
    {
        var content = """
            
            not a line
            e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  file.zip
            
            """;

        var map = ChecksumVerifier.ParseChecksumsFile(content);

        Assert.Single(map);
        Assert.True(map.ContainsKey("file.zip"));
    }
}
```

- [ ] **Step 2: Run to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter ChecksumVerifierTests`
Expected: FAIL (type not defined).

- [ ] **Step 3: Implement `ChecksumVerifier`**

Create `src/ClaudeDo.Installer/Core/ChecksumVerifier.cs`:

```csharp
using System.IO;
using System.Security.Cryptography;

namespace ClaudeDo.Installer.Core;

public static class ChecksumVerifier
{
    public static string ComputeSha256(string filePath)
    {
        using var stream = File.OpenRead(filePath);
        using var sha = SHA256.Create();
        var hash = sha.ComputeHash(stream);
        return Convert.ToHexString(hash).ToLowerInvariant();
    }

    public static bool Verify(string filePath, string expectedSha256)
    {
        var actual = ComputeSha256(filePath);
        return string.Equals(actual, expectedSha256.Trim(), StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>
    /// Parses a standard `sha256sum` output: "&lt;hash&gt;  &lt;filename&gt;" per line.
    /// Returns a map keyed by filename.
    /// </summary>
    public static IReadOnlyDictionary<string, string> ParseChecksumsFile(string content)
    {
        var map = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
        foreach (var rawLine in content.Split('\n'))
        {
            var line = rawLine.Trim();
            if (line.Length == 0) continue;
            var parts = line.Split(new[] { ' ', '\t' }, 2, StringSplitOptions.RemoveEmptyEntries);
            if (parts.Length != 2) continue;
            map[parts[1].Trim()] = parts[0].Trim();
        }
        return map;
    }
}
```

- [ ] **Step 4: Run to verify it passes**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter ChecksumVerifierTests`
Expected: PASS (7 tests).

- [ ] **Step 5: Commit**

```bash
git add src/ClaudeDo.Installer/Core/ChecksumVerifier.cs tests/ClaudeDo.Installer.Tests/ChecksumVerifierTests.cs
git commit -m "feat(installer): add ChecksumVerifier (SHA256 + checksums.txt parser)"
```

---

## Task 4: `IReleaseClient` + `ReleaseClient`

**Files:**
- Create: `src/ClaudeDo.Installer/Core/IReleaseClient.cs`
- Create: `src/ClaudeDo.Installer/Core/ReleaseClient.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/ReleaseClientTests.cs`

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/ReleaseClientTests.cs`:

```csharp
using System.Net;
using System.Net.Http;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Tests;

public sealed class ReleaseClientTests
{
    private const string ApiBase = "https://git.example.test/api/v1/repos/releases/ClaudeDo";

    [Fact]
    public async Task GetLatestReleaseAsync_ParsesTagAndAssets()
    {
        const string json = """
            {
              "tag_name": "v0.2.0",
              "name": "v0.2.0",
              "assets": [
                {
                  "name": "ClaudeDo-0.2.0-win-x64.zip",
                  "browser_download_url": "https://git.example.test/dl/zip",
                  "size": 12345
                },
                {
                  "name": "checksums.txt",
                  "browser_download_url": "https://git.example.test/dl/checksums",
                  "size": 128
                }
              ]
            }
            """;

        var handler = new FakeHttpMessageHandler(HttpStatusCode.OK, json);
        using var http = new HttpClient(handler);
        var client = new ReleaseClient(http, ApiBase);

        var release = await client.GetLatestReleaseAsync(CancellationToken.None);

        Assert.NotNull(release);
        Assert.Equal("v0.2.0", release!.TagName);
        Assert.Equal(2, release.Assets.Count);
        Assert.Equal("ClaudeDo-0.2.0-win-x64.zip", release.Assets[0].Name);
        Assert.Equal("https://git.example.test/dl/zip", release.Assets[0].BrowserDownloadUrl);
        Assert.Equal(12345, release.Assets[0].Size);
    }

    [Fact]
    public async Task GetLatestReleaseAsync_Returns_Null_On404()
    {
        var handler = new FakeHttpMessageHandler(HttpStatusCode.NotFound, "");
        using var http = new HttpClient(handler);
        var client = new ReleaseClient(http, ApiBase);

        var release = await client.GetLatestReleaseAsync(CancellationToken.None);

        Assert.Null(release);
    }

    [Fact]
    public async Task GetLatestReleaseAsync_Returns_Null_OnNetworkError()
    {
        var handler = new FakeHttpMessageHandler(_ => throw new HttpRequestException("boom"));
        using var http = new HttpClient(handler);
        var client = new ReleaseClient(http, ApiBase);

        var release = await client.GetLatestReleaseAsync(CancellationToken.None);

        Assert.Null(release);
    }

    [Fact]
    public async Task GetLatestReleaseAsync_Hits_CorrectUrl()
    {
        var handler = new FakeHttpMessageHandler(HttpStatusCode.OK, "{\"tag_name\":\"v0.1.0\",\"assets\":[]}");
        using var http = new HttpClient(handler);
        var client = new ReleaseClient(http, ApiBase);

        _ = await client.GetLatestReleaseAsync(CancellationToken.None);

        Assert.Single(handler.Requests);
        Assert.Equal($"{ApiBase}/releases/latest", handler.Requests[0].RequestUri!.ToString());
    }

    [Fact]
    public async Task DownloadAsync_WritesBytesToDisk()
    {
        var payload = new byte[] { 1, 2, 3, 4, 5 };
        var handler = new FakeHttpMessageHandler(_ => new HttpResponseMessage(HttpStatusCode.OK)
        {
            Content = new ByteArrayContent(payload)
        });
        using var http = new HttpClient(handler);
        var client = new ReleaseClient(http, ApiBase);

        var tempPath = Path.Combine(Path.GetTempPath(), "ClaudeDoDlTest-" + Guid.NewGuid().ToString("N"));
        try
        {
            await client.DownloadAsync("https://example/foo", tempPath,
                new Progress<long>(_ => { }), CancellationToken.None);

            Assert.True(File.Exists(tempPath));
            Assert.Equal(payload, File.ReadAllBytes(tempPath));
        }
        finally
        {
            if (File.Exists(tempPath)) File.Delete(tempPath);
        }
    }
}
```

- [ ] **Step 2: Run to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter ReleaseClientTests`
Expected: FAIL (types not defined).

- [ ] **Step 3: Implement `IReleaseClient`**

Create `src/ClaudeDo.Installer/Core/IReleaseClient.cs`:

```csharp
namespace ClaudeDo.Installer.Core;

public sealed record ReleaseAsset(string Name, string BrowserDownloadUrl, long Size);

public sealed record GiteaRelease(
    string TagName,
    string Name,
    IReadOnlyList<ReleaseAsset> Assets);

public interface IReleaseClient
{
    Task<GiteaRelease?> GetLatestReleaseAsync(CancellationToken ct);

    Task DownloadAsync(string url, string destPath, IProgress<long> progress, CancellationToken ct);
}
```

- [ ] **Step 4: Implement `ReleaseClient`**

Create `src/ClaudeDo.Installer/Core/ReleaseClient.cs`:

```csharp
using System.IO;
using System.Net.Http;
using System.Text.Json;

namespace ClaudeDo.Installer.Core;

public sealed class ReleaseClient : IReleaseClient
{
    public const string DefaultApiBase = "https://git.kuns.dev/api/v1/repos/releases/ClaudeDo";

    private readonly HttpClient _http;
    private readonly string _apiBase;

    public ReleaseClient(HttpClient http, string apiBase = DefaultApiBase)
    {
        _http = http;
        _apiBase = apiBase.TrimEnd('/');
    }

    public async Task<GiteaRelease?> GetLatestReleaseAsync(CancellationToken ct)
    {
        try
        {
            using var response = await _http.GetAsync($"{_apiBase}/releases/latest", ct);
            if (!response.IsSuccessStatusCode) return null;
            var json = await response.Content.ReadAsStringAsync(ct);
            return ParseRelease(json);
        }
        catch (HttpRequestException) { return null; }
        catch (TaskCanceledException) { return null; }
    }

    public async Task DownloadAsync(string url, string destPath, IProgress<long> progress, CancellationToken ct)
    {
        using var response = await _http.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, ct);
        response.EnsureSuccessStatusCode();

        await using var input = await response.Content.ReadAsStreamAsync(ct);
        await using var output = File.Create(destPath);

        var buffer = new byte[81920];
        long total = 0;
        int read;
        while ((read = await input.ReadAsync(buffer, ct)) > 0)
        {
            await output.WriteAsync(buffer.AsMemory(0, read), ct);
            total += read;
            progress.Report(total);
        }
    }

    private static GiteaRelease? ParseRelease(string json)
    {
        try
        {
            using var doc = JsonDocument.Parse(json);
            var root = doc.RootElement;
            if (!root.TryGetProperty("tag_name", out var tagEl)) return null;

            var tag = tagEl.GetString() ?? "";
            var name = root.TryGetProperty("name", out var nameEl) ? (nameEl.GetString() ?? "") : "";

            var assets = new List<ReleaseAsset>();
            if (root.TryGetProperty("assets", out var arr) && arr.ValueKind == JsonValueKind.Array)
            {
                foreach (var item in arr.EnumerateArray())
                {
                    var aName = item.GetProperty("name").GetString() ?? "";
                    var aUrl = item.GetProperty("browser_download_url").GetString() ?? "";
                    var aSize = item.TryGetProperty("size", out var s) ? s.GetInt64() : 0L;
                    assets.Add(new ReleaseAsset(aName, aUrl, aSize));
                }
            }

            return new GiteaRelease(tag, name, assets);
        }
        catch (JsonException)
        {
            return null;
        }
    }
}
```

- [ ] **Step 5: Run to verify tests pass**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter ReleaseClientTests`
Expected: PASS (5 tests).

- [ ] **Step 6: Commit**

```bash
git add src/ClaudeDo.Installer/Core/IReleaseClient.cs src/ClaudeDo.Installer/Core/ReleaseClient.cs tests/ClaudeDo.Installer.Tests/ReleaseClientTests.cs
git commit -m "feat(installer): add IReleaseClient + Gitea ReleaseClient"
```

---

## Task 5: Expand `InstallerMode` + add `InstallModeDetector`

**Files:**
- Modify: `src/ClaudeDo.Installer/Core/InstallerMode.cs`
- Create: `src/ClaudeDo.Installer/Core/InstallModeDetector.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/InstallModeDetectorTests.cs`

The existing file has:

```csharp
public enum InstallerMode { Wizard, Settings }
public static class ModeDetector { public static InstallerMode Detect() { ... } }
```

We replace both. The old `ModeDetector` looks at `~/.todo-app/*.json`, but that's the *worker/ui config*, not an install manifest. We now key off `{InstallDir}/install.json`, which is the authoritative "is ClaudeDo installed" signal.

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/InstallModeDetectorTests.cs`:

```csharp
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Tests;

public sealed class InstallModeDetectorTests : IDisposable
{
    private readonly string _tempDir;

    public InstallModeDetectorTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), "ClaudeDoDetector-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_tempDir);
    }

    public void Dispose()
    {
        try { Directory.Delete(_tempDir, recursive: true); } catch { }
    }

    private sealed class FakeReleaseClient : IReleaseClient
    {
        public GiteaRelease? Release { get; set; }
        public Task<GiteaRelease?> GetLatestReleaseAsync(CancellationToken ct) => Task.FromResult(Release);
        public Task DownloadAsync(string url, string destPath, IProgress<long> progress, CancellationToken ct)
            => throw new NotSupportedException();
    }

    [Fact]
    public async Task Detect_FreshInstall_WhenManifestMissing()
    {
        var detector = new InstallModeDetector(new FakeReleaseClient());

        var state = await detector.DetectAsync(_tempDir, CancellationToken.None);

        Assert.Equal(InstallerMode.FreshInstall, state.Mode);
        Assert.Null(state.Existing);
    }

    [Fact]
    public async Task Detect_Config_WhenManifestPresent_And_Api_Unreachable()
    {
        InstallManifestStore.Write(_tempDir,
            new InstallManifest("0.1.0", _tempDir, _tempDir, DateTimeOffset.UtcNow));

        var detector = new InstallModeDetector(new FakeReleaseClient { Release = null });

        var state = await detector.DetectAsync(_tempDir, CancellationToken.None);

        Assert.Equal(InstallerMode.Config, state.Mode);
        Assert.Equal("0.1.0", state.Existing!.Version);
    }

    [Fact]
    public async Task Detect_Update_WhenLatest_GreaterThan_Installed()
    {
        InstallManifestStore.Write(_tempDir,
            new InstallManifest("0.1.0", _tempDir, _tempDir, DateTimeOffset.UtcNow));

        var fake = new FakeReleaseClient
        {
            Release = new GiteaRelease("v0.2.0", "v0.2.0", Array.Empty<ReleaseAsset>())
        };
        var detector = new InstallModeDetector(fake);

        var state = await detector.DetectAsync(_tempDir, CancellationToken.None);

        Assert.Equal(InstallerMode.Update, state.Mode);
        Assert.Equal("0.1.0", state.Existing!.Version);
        Assert.Equal("0.2.0", state.LatestVersion);
    }

    [Fact]
    public async Task Detect_Config_WhenLatest_EqualsOrOlderThan_Installed()
    {
        InstallManifestStore.Write(_tempDir,
            new InstallManifest("0.2.0", _tempDir, _tempDir, DateTimeOffset.UtcNow));

        var fake = new FakeReleaseClient
        {
            Release = new GiteaRelease("v0.2.0", "v0.2.0", Array.Empty<ReleaseAsset>())
        };
        var detector = new InstallModeDetector(fake);

        var state = await detector.DetectAsync(_tempDir, CancellationToken.None);

        Assert.Equal(InstallerMode.Config, state.Mode);
    }

    [Fact]
    public async Task Detect_Config_WhenInstalledIs_Newer_Than_Latest()
    {
        // Installed from a newer tag than latest release — don't offer downgrade.
        InstallManifestStore.Write(_tempDir,
            new InstallManifest("0.3.0", _tempDir, _tempDir, DateTimeOffset.UtcNow));

        var fake = new FakeReleaseClient
        {
            Release = new GiteaRelease("v0.2.0", "v0.2.0", Array.Empty<ReleaseAsset>())
        };
        var detector = new InstallModeDetector(fake);

        var state = await detector.DetectAsync(_tempDir, CancellationToken.None);

        Assert.Equal(InstallerMode.Config, state.Mode);
    }
}
```

- [ ] **Step 2: Run to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter InstallModeDetectorTests`
Expected: FAIL (types not defined / enum values missing).

- [ ] **Step 3: Replace `InstallerMode.cs` content**

Fully replace `src/ClaudeDo.Installer/Core/InstallerMode.cs` with:

```csharp
namespace ClaudeDo.Installer.Core;

public enum InstallerMode
{
    FreshInstall,   // No install.json present -> run full wizard
    Update,         // install.json present, newer release available
    Config,         // install.json present, no update (or API unreachable)
}
```

The old synchronous `ModeDetector.Detect()` is removed — replaced by `InstallModeDetector` below.

- [ ] **Step 4: Implement `InstallModeDetector`**

Create `src/ClaudeDo.Installer/Core/InstallModeDetector.cs`:

```csharp
namespace ClaudeDo.Installer.Core;

public sealed record DetectedState(
    InstallerMode Mode,
    InstallManifest? Existing,
    GiteaRelease? LatestRelease,
    string? LatestVersion);

public sealed class InstallModeDetector
{
    private readonly IReleaseClient _releases;

    public InstallModeDetector(IReleaseClient releases)
    {
        _releases = releases;
    }

    public async Task<DetectedState> DetectAsync(string installDir, CancellationToken ct)
    {
        var manifest = InstallManifestStore.TryRead(installDir);
        if (manifest is null)
            return new DetectedState(InstallerMode.FreshInstall, null, null, null);

        var release = await _releases.GetLatestReleaseAsync(ct);
        if (release is null)
            return new DetectedState(InstallerMode.Config, manifest, null, null);

        var latestVersion = release.TagName.TrimStart('v', 'V');
        if (IsNewer(latestVersion, manifest.Version))
            return new DetectedState(InstallerMode.Update, manifest, release, latestVersion);

        return new DetectedState(InstallerMode.Config, manifest, release, latestVersion);
    }

    private static bool IsNewer(string latest, string current)
    {
        if (!Version.TryParse(latest, out var lv)) return false;
        if (!Version.TryParse(current, out var cv)) return false;
        return lv > cv;
    }
}
```

- [ ] **Step 5: Run to verify it passes**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter InstallModeDetectorTests`
Expected: PASS (5 tests).

- [ ] **Step 6: Commit**

```bash
git add src/ClaudeDo.Installer/Core/InstallerMode.cs src/ClaudeDo.Installer/Core/InstallModeDetector.cs tests/ClaudeDo.Installer.Tests/InstallModeDetectorTests.cs
git commit -m "feat(installer): replace sync ModeDetector with async InstallModeDetector"
```

Note: this commit temporarily breaks `App.xaml.cs` which still references `ModeDetector.Detect()`. That's fixed in Task 11; it's fine for an intermediate commit because `dotnet test` on the test project succeeds and the installer project build error is expected until the wiring task. **If you want to keep every commit green**, stash this commit and squash it into Task 11 — otherwise leave it.

---

## Task 6: `StopServiceStep` + `StartServiceStep`

**Files:**
- Create: `src/ClaudeDo.Installer/Steps/StopServiceStep.cs`
- Create: `src/ClaudeDo.Installer/Steps/StartServiceStep.cs`

Both are thin `sc.exe` wrappers. Manual verification only — tests would need Administrator + a real service, not worth the setup.

- [ ] **Step 1: Implement `StopServiceStep`**

Create `src/ClaudeDo.Installer/Steps/StopServiceStep.cs`:

```csharp
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Steps;

public sealed class StopServiceStep : IInstallStep
{
    public const string ServiceName = "ClaudeDoWorker";

    public string Name => "Stop Worker Service";

    public async Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
    {
        progress.Report($"Stopping {ServiceName} (if running)...");

        // sc.exe query -> returns non-zero if the service does not exist; that's fine.
        var (queryExit, queryOutput) = await ProcessRunner.RunAsync("sc.exe", $"query {ServiceName}", null, progress, ct);
        if (queryExit != 0)
        {
            progress.Report("Service is not registered — nothing to stop.");
            return StepResult.Ok();
        }

        if (queryOutput.Contains("STOPPED", StringComparison.OrdinalIgnoreCase))
        {
            progress.Report("Service is already stopped.");
            return StepResult.Ok();
        }

        var (stopExit, _) = await ProcessRunner.RunAsync("sc.exe", $"stop {ServiceName}", null, progress, ct);
        if (stopExit != 0)
            return StepResult.Fail($"sc.exe stop failed with exit code {stopExit}");

        // Poll until stopped or timeout (up to 30s).
        for (var i = 0; i < 30; i++)
        {
            ct.ThrowIfCancellationRequested();
            await Task.Delay(1000, ct);
            var (e, o) = await ProcessRunner.RunAsync("sc.exe", $"query {ServiceName}", null, progress, ct);
            if (e != 0 || o.Contains("STOPPED", StringComparison.OrdinalIgnoreCase))
            {
                progress.Report("Service stopped.");
                return StepResult.Ok();
            }
        }

        return StepResult.Fail("Service did not stop within 30 seconds.");
    }
}
```

- [ ] **Step 2: Implement `StartServiceStep`**

Create `src/ClaudeDo.Installer/Steps/StartServiceStep.cs`:

```csharp
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Steps;

public sealed class StartServiceStep : IInstallStep
{
    private const string ServiceName = StopServiceStep.ServiceName;

    public string Name => "Start Worker Service";

    public async Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
    {
        progress.Report($"Starting {ServiceName}...");

        var (exit, output) = await ProcessRunner.RunAsync("sc.exe", $"start {ServiceName}", null, progress, ct);
        if (exit == 0) return StepResult.Ok();

        // Exit 1056 = already running — that's fine too.
        if (output.Contains("1056", StringComparison.OrdinalIgnoreCase))
        {
            progress.Report("Service was already running.");
            return StepResult.Ok();
        }

        return StepResult.Fail($"sc.exe start failed with exit code {exit}");
    }
}
```

- [ ] **Step 3: Verify the project still builds**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: Build succeeds (steps aren't wired into DI yet — that's Task 11).

- [ ] **Step 4: Commit**

```bash
git add src/ClaudeDo.Installer/Steps/StopServiceStep.cs src/ClaudeDo.Installer/Steps/StartServiceStep.cs
git commit -m "feat(installer): add Stop/StartServiceStep sc.exe wrappers"
```

---

## Task 7: `DownloadAndExtractStep`

**Files:**
- Create: `src/ClaudeDo.Installer/Steps/DownloadAndExtractStep.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/DownloadAndExtractStepTests.cs`

This step is the heart of the new flow. Test strategy: build a real zip on disk, stand up a `FakeReleaseClient` that "downloads" by copying the prebuilt file, and verify extraction + checksum handling.

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/DownloadAndExtractStepTests.cs`:

```csharp
using System.IO;
using System.IO.Compression;
using ClaudeDo.Installer.Core;
using ClaudeDo.Installer.Steps;

namespace ClaudeDo.Installer.Tests;

public sealed class DownloadAndExtractStepTests : IDisposable
{
    private readonly string _tempDir;
    private readonly string _installDir;

    public DownloadAndExtractStepTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), "ClaudeDoDownloadStep-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_tempDir);
        _installDir = Path.Combine(_tempDir, "install");
        Directory.CreateDirectory(_installDir);
    }

    public void Dispose()
    {
        try { Directory.Delete(_tempDir, recursive: true); } catch { }
    }

    private sealed class FileCopyReleaseClient : IReleaseClient
    {
        private readonly Dictionary<string, string> _urlToSourceFile;
        public GiteaRelease? Release { get; set; }

        public FileCopyReleaseClient(Dictionary<string, string> urlToSourceFile)
            => _urlToSourceFile = urlToSourceFile;

        public Task<GiteaRelease?> GetLatestReleaseAsync(CancellationToken ct) => Task.FromResult(Release);

        public Task DownloadAsync(string url, string destPath, IProgress<long> progress, CancellationToken ct)
        {
            File.Copy(_urlToSourceFile[url], destPath, overwrite: true);
            progress.Report(new FileInfo(destPath).Length);
            return Task.CompletedTask;
        }
    }

    [Fact]
    public async Task Extracts_Zip_Into_InstallDir_App_And_Worker()
    {
        // Arrange: build a zip with /app/a.txt and /worker/b.txt
        var zipPath = Path.Combine(_tempDir, "release.zip");
        using (var fs = File.Create(zipPath))
        using (var zip = new ZipArchive(fs, ZipArchiveMode.Create))
        {
            var a = zip.CreateEntry("app/a.txt");
            using (var w = new StreamWriter(a.Open())) w.Write("hello-app");
            var b = zip.CreateEntry("worker/b.txt");
            using (var w = new StreamWriter(b.Open())) w.Write("hello-worker");
        }

        var zipHash = ChecksumVerifier.ComputeSha256(zipPath);
        var checksumsPath = Path.Combine(_tempDir, "checksums.txt");
        File.WriteAllText(checksumsPath, $"{zipHash}  ClaudeDo-0.1.0-win-x64.zip\n");

        var release = new GiteaRelease("v0.1.0", "v0.1.0", new[]
        {
            new ReleaseAsset("ClaudeDo-0.1.0-win-x64.zip", "fake://zip", new FileInfo(zipPath).Length),
            new ReleaseAsset("checksums.txt", "fake://checksums", new FileInfo(checksumsPath).Length),
        });

        var client = new FileCopyReleaseClient(new()
        {
            ["fake://zip"] = zipPath,
            ["fake://checksums"] = checksumsPath,
        }) { Release = release };

        var step = new DownloadAndExtractStep(client);
        var ctx = new InstallContext { InstallDirectory = _installDir };

        // Act
        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        // Assert
        Assert.True(result.Success, result.ErrorMessage);
        Assert.Equal("hello-app", File.ReadAllText(Path.Combine(_installDir, "app", "a.txt")));
        Assert.Equal("hello-worker", File.ReadAllText(Path.Combine(_installDir, "worker", "b.txt")));
    }

    [Fact]
    public async Task Fails_On_ChecksumMismatch_Without_Overwriting_InstallDir()
    {
        // Arrange: zip is valid, but checksums.txt says something else.
        var zipPath = Path.Combine(_tempDir, "release.zip");
        using (var fs = File.Create(zipPath))
        using (var zip = new ZipArchive(fs, ZipArchiveMode.Create))
        {
            var a = zip.CreateEntry("app/a.txt");
            using (var w = new StreamWriter(a.Open())) w.Write("x");
        }

        var checksumsPath = Path.Combine(_tempDir, "checksums.txt");
        File.WriteAllText(checksumsPath, $"{new string('0', 64)}  ClaudeDo-0.1.0-win-x64.zip\n");

        // Pre-populate install dir — it must NOT be modified on failure.
        File.WriteAllText(Path.Combine(_installDir, "marker.txt"), "untouched");

        var release = new GiteaRelease("v0.1.0", "v0.1.0", new[]
        {
            new ReleaseAsset("ClaudeDo-0.1.0-win-x64.zip", "fake://zip", 0),
            new ReleaseAsset("checksums.txt", "fake://checksums", 0),
        });

        var client = new FileCopyReleaseClient(new()
        {
            ["fake://zip"] = zipPath,
            ["fake://checksums"] = checksumsPath,
        }) { Release = release };

        var step = new DownloadAndExtractStep(client);
        var ctx = new InstallContext { InstallDirectory = _installDir };

        // Act
        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        // Assert
        Assert.False(result.Success);
        Assert.Contains("checksum", result.ErrorMessage!, StringComparison.OrdinalIgnoreCase);
        Assert.True(File.Exists(Path.Combine(_installDir, "marker.txt")));
        Assert.False(Directory.Exists(Path.Combine(_installDir, "app")));
    }

    [Fact]
    public async Task Fails_When_Release_Has_No_Zip_Asset()
    {
        var release = new GiteaRelease("v0.1.0", "v0.1.0", Array.Empty<ReleaseAsset>());
        var client = new FileCopyReleaseClient(new()) { Release = release };
        var step = new DownloadAndExtractStep(client);
        var ctx = new InstallContext { InstallDirectory = _installDir };

        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        Assert.False(result.Success);
        Assert.Contains("not found", result.ErrorMessage!, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public async Task Fails_When_ReleaseClient_Returns_Null()
    {
        var client = new FileCopyReleaseClient(new()) { Release = null };
        var step = new DownloadAndExtractStep(client);
        var ctx = new InstallContext { InstallDirectory = _installDir };

        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        Assert.False(result.Success);
    }
}
```

- [ ] **Step 2: Run to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter DownloadAndExtractStepTests`
Expected: FAIL (type not defined).

- [ ] **Step 3: Implement `DownloadAndExtractStep`**

Create `src/ClaudeDo.Installer/Steps/DownloadAndExtractStep.cs`:

```csharp
using System.IO;
using System.IO.Compression;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Steps;

public sealed class DownloadAndExtractStep : IInstallStep
{
    private readonly IReleaseClient _releases;

    public DownloadAndExtractStep(IReleaseClient releases)
    {
        _releases = releases;
    }

    public string Name => "Download and Extract";

    public async Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
    {
        progress.Report("Fetching latest release metadata...");
        var release = await _releases.GetLatestReleaseAsync(ct);
        if (release is null)
            return StepResult.Fail("Could not reach the release server. Check your network connection and try again.");

        var zipAsset = release.Assets.FirstOrDefault(a =>
            a.Name.StartsWith("ClaudeDo-", StringComparison.OrdinalIgnoreCase) &&
            a.Name.EndsWith(".zip", StringComparison.OrdinalIgnoreCase));
        var checksumAsset = release.Assets.FirstOrDefault(a =>
            a.Name.Equals("checksums.txt", StringComparison.OrdinalIgnoreCase));

        if (zipAsset is null)
            return StepResult.Fail("Release zip asset not found in release metadata.");
        if (checksumAsset is null)
            return StepResult.Fail("checksums.txt not found in release metadata.");

        var scratchDir = Path.Combine(Path.GetTempPath(), "ClaudeDo-install-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(scratchDir);

        try
        {
            var zipPath = Path.Combine(scratchDir, zipAsset.Name);
            var checksumPath = Path.Combine(scratchDir, "checksums.txt");

            progress.Report($"Downloading {zipAsset.Name} ({zipAsset.Size / (1024 * 1024)} MB)...");
            await _releases.DownloadAsync(zipAsset.BrowserDownloadUrl, zipPath,
                new Progress<long>(b => progress.Report($"  {b / (1024 * 1024)} MB downloaded")),
                ct);

            progress.Report("Downloading checksums...");
            await _releases.DownloadAsync(checksumAsset.BrowserDownloadUrl, checksumPath,
                new Progress<long>(_ => { }), ct);

            progress.Report("Verifying checksum...");
            var map = ChecksumVerifier.ParseChecksumsFile(File.ReadAllText(checksumPath));
            if (!map.TryGetValue(zipAsset.Name, out var expectedHash))
                return StepResult.Fail($"No checksum entry for {zipAsset.Name} in checksums.txt.");
            if (!ChecksumVerifier.Verify(zipPath, expectedHash))
                return StepResult.Fail("Checksum mismatch — the downloaded zip may be corrupt or tampered with.");

            // Only after verification do we touch the install directory.
            progress.Report("Clearing previous app/worker binaries...");
            var appDest = Path.Combine(ctx.InstallDirectory, "app");
            var workerDest = Path.Combine(ctx.InstallDirectory, "worker");
            if (Directory.Exists(appDest)) Directory.Delete(appDest, recursive: true);
            if (Directory.Exists(workerDest)) Directory.Delete(workerDest, recursive: true);

            progress.Report("Extracting...");
            Directory.CreateDirectory(ctx.InstallDirectory);
            ZipFile.ExtractToDirectory(zipPath, ctx.InstallDirectory, overwriteFiles: true);

            // Stash the latest version in the context so WriteInstallManifestStep can persist it.
            ctx.InstalledVersion = release.TagName.TrimStart('v', 'V');
            return StepResult.Ok();
        }
        finally
        {
            try { Directory.Delete(scratchDir, recursive: true); } catch { /* best effort */ }
        }
    }
}
```

- [ ] **Step 4: Temporarily add `InstalledVersion` to `InstallContext` so the test compiles**

Modify `src/ClaudeDo.Installer/Core/InstallContext.cs`: add this line anywhere inside the class:

```csharp
    public string? InstalledVersion { get; set; }
```

(The full `InstallContext` overhaul is Task 10 — this is a partial change so this task's tests compile.)

- [ ] **Step 5: Run to verify it passes**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter DownloadAndExtractStepTests`
Expected: PASS (4 tests).

- [ ] **Step 6: Commit**

```bash
git add src/ClaudeDo.Installer/Steps/DownloadAndExtractStep.cs src/ClaudeDo.Installer/Core/InstallContext.cs tests/ClaudeDo.Installer.Tests/DownloadAndExtractStepTests.cs
git commit -m "feat(installer): add DownloadAndExtractStep with SHA256 verify"
```

---

## Task 8: `WriteInstallManifestStep`

**Files:**
- Create: `src/ClaudeDo.Installer/Steps/WriteInstallManifestStep.cs`
- Test:   `tests/ClaudeDo.Installer.Tests/WriteInstallManifestStepTests.cs`

- [ ] **Step 1: Write the failing test**

Create `tests/ClaudeDo.Installer.Tests/WriteInstallManifestStepTests.cs`:

```csharp
using ClaudeDo.Installer.Core;
using ClaudeDo.Installer.Steps;

namespace ClaudeDo.Installer.Tests;

public sealed class WriteInstallManifestStepTests : IDisposable
{
    private readonly string _installDir;

    public WriteInstallManifestStepTests()
    {
        _installDir = Path.Combine(Path.GetTempPath(), "ClaudeDoWriteManifest-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_installDir);
    }

    public void Dispose()
    {
        try { Directory.Delete(_installDir, recursive: true); } catch { }
    }

    [Fact]
    public async Task Writes_Manifest_WithAllFields()
    {
        var ctx = new InstallContext
        {
            InstallDirectory = _installDir,
            InstalledVersion = "0.2.0",
        };

        var step = new WriteInstallManifestStep();
        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        Assert.True(result.Success);
        var manifest = InstallManifestStore.TryRead(_installDir);
        Assert.NotNull(manifest);
        Assert.Equal("0.2.0", manifest!.Version);
        Assert.Equal(_installDir, manifest.InstallDir);
        Assert.Equal(Path.Combine(_installDir, "worker"), manifest.WorkerDir);
    }

    [Fact]
    public async Task Fails_When_InstalledVersion_Missing()
    {
        var ctx = new InstallContext { InstallDirectory = _installDir };  // no version set

        var step = new WriteInstallManifestStep();
        var result = await step.ExecuteAsync(ctx, new Progress<string>(_ => { }), CancellationToken.None);

        Assert.False(result.Success);
    }
}
```

- [ ] **Step 2: Run to verify it fails**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter WriteInstallManifestStepTests`
Expected: FAIL (type not defined).

- [ ] **Step 3: Implement the step**

Create `src/ClaudeDo.Installer/Steps/WriteInstallManifestStep.cs`:

```csharp
using System.IO;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Steps;

public sealed class WriteInstallManifestStep : IInstallStep
{
    public string Name => "Write Install Manifest";

    public Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(ctx.InstalledVersion))
            return Task.FromResult(StepResult.Fail("Installed version is not set — DownloadAndExtractStep must run first."));

        var manifest = new InstallManifest(
            Version: ctx.InstalledVersion!,
            InstallDir: ctx.InstallDirectory,
            WorkerDir: Path.Combine(ctx.InstallDirectory, "worker"),
            InstalledAt: DateTimeOffset.UtcNow);

        InstallManifestStore.Write(ctx.InstallDirectory, manifest);
        progress.Report($"Wrote {InstallManifestStore.ManifestPath(ctx.InstallDirectory)}");
        return Task.FromResult(StepResult.Ok());
    }
}
```

- [ ] **Step 4: Run to verify it passes**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --filter WriteInstallManifestStepTests`
Expected: PASS (2 tests).

- [ ] **Step 5: Commit**

```bash
git add src/ClaudeDo.Installer/Steps/WriteInstallManifestStep.cs tests/ClaudeDo.Installer.Tests/WriteInstallManifestStepTests.cs
git commit -m "feat(installer): add WriteInstallManifestStep"
```

---

## Task 9: Delete obsolete publish/deploy steps

**Files:**
- Delete: `src/ClaudeDo.Installer/Steps/PublishAppStep.cs`
- Delete: `src/ClaudeDo.Installer/Steps/PublishWorkerStep.cs`
- Delete: `src/ClaudeDo.Installer/Steps/DeployBinariesStep.cs`

- [ ] **Step 1: Delete the three files**

```bash
rm src/ClaudeDo.Installer/Steps/PublishAppStep.cs
rm src/ClaudeDo.Installer/Steps/PublishWorkerStep.cs
rm src/ClaudeDo.Installer/Steps/DeployBinariesStep.cs
```

The installer project will not build until Task 11 removes the DI registrations, but deleting now keeps the diff small and tidy.

- [ ] **Step 2: Commit**

```bash
git add -A src/ClaudeDo.Installer/Steps
git commit -m "refactor(installer): remove source-build steps (replaced by DownloadAndExtractStep)"
```

---

## Task 10: Update `InstallContext`

Drop `SourceDirectory` (no longer needed — no source is required), and add version/mode fields.

**Files:**
- Modify: `src/ClaudeDo.Installer/Core/InstallContext.cs`

- [ ] **Step 1: Replace the file**

Fully replace `src/ClaudeDo.Installer/Core/InstallContext.cs` with:

```csharp
namespace ClaudeDo.Installer.Core;

public sealed class InstallContext
{
    // WelcomePage / install destination
    public string InstallDirectory { get; set; } = @"C:\Program Files\ClaudeDo";

    // Mode + versions (set by App startup after InstallModeDetector runs)
    public InstallerMode Mode { get; set; } = InstallerMode.FreshInstall;
    public string? InstallerVersion { get; set; }   // from this installer's assembly
    public string? InstalledVersion { get; set; }   // from install.json (or set by DownloadAndExtractStep)
    public string? LatestVersion { get; set; }      // from Gitea API (may be null if offline)

    // PathsPage
    public string DbPath { get; set; } = "~/.todo-app/todo.db";
    public string LogRoot { get; set; } = "~/.todo-app/logs";
    public string SandboxRoot { get; set; } = "~/.todo-app/sandbox";
    public string WorktreeRootStrategy { get; set; } = "sibling";
    public string CentralWorktreeRoot { get; set; } = "~/.todo-app/worktrees";

    // ServicePage
    public int SignalRPort { get; set; } = 47_821;
    public int QueueBackstopIntervalMs { get; set; } = 30_000;
    public string ClaudeBin { get; set; } = "claude";
    public string ServiceAccount { get; set; } = "LocalSystem";
    public bool AutoStart { get; set; } = true;
    public int RestartDelayMs { get; set; } = 5000;

    // UiSettingsPage
    public string SignalRUrl { get; set; } = "http://127.0.0.1:47821/hub";
    public string UiDbPath { get; set; } = "~/.todo-app/todo.db";

    // InstallPage
    public bool CreateDesktopShortcut { get; set; } = true;
}
```

- [ ] **Step 2: Verify the tests still build**

Run: `dotnet test tests/ClaudeDo.Installer.Tests --no-restore --list-tests`
Expected: Compilation succeeds (installer project still broken — that's Task 11).

- [ ] **Step 3: Commit**

```bash
git add src/ClaudeDo.Installer/Core/InstallContext.cs
git commit -m "refactor(installer): replace SourceDirectory with Mode/Version fields in InstallContext"
```

---

## Task 11: Wire new mode-aware startup + DI in `App.xaml.cs`

This is the big wiring task. Done right, every later task is a small UI tweak.

**Files:**
- Modify: `src/ClaudeDo.Installer/App.xaml.cs`

- [ ] **Step 1: Replace the file**

Fully replace `src/ClaudeDo.Installer/App.xaml.cs` with:

```csharp
using System.IO;
using System.Net.Http;
using System.Reflection;
using System.Windows;
using ClaudeDo.Installer.Core;
using ClaudeDo.Installer.Pages.InstallPage;
using ClaudeDo.Installer.Pages.PathsPage;
using ClaudeDo.Installer.Pages.ServicePage;
using ClaudeDo.Installer.Pages.UiSettingsPage;
using ClaudeDo.Installer.Pages.WelcomePage;
using ClaudeDo.Installer.Steps;
using ClaudeDo.Installer.Views;
using Microsoft.Extensions.DependencyInjection;

namespace ClaudeDo.Installer;

public partial class App : Application
{
    private ServiceProvider? _services;

    protected override async void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);

        _services = BuildServices();

        var context = _services.GetRequiredService<InstallContext>();
        context.InstallerVersion = GetInstallerVersion();

        // Default install dir for detection — on upgrade we stay where we were.
        var detector = _services.GetRequiredService<InstallModeDetector>();
        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
        DetectedState state;
        try
        {
            state = await detector.DetectAsync(context.InstallDirectory, cts.Token);
        }
        catch (OperationCanceledException)
        {
            state = new DetectedState(InstallerMode.FreshInstall, null, null, null);
        }

        context.Mode = state.Mode;
        context.InstalledVersion = state.Existing?.Version;
        context.LatestVersion = state.LatestVersion;
        if (state.Existing is not null)
            context.InstallDirectory = state.Existing.InstallDir;

        Window mainWindow = state.Mode switch
        {
            InstallerMode.FreshInstall or InstallerMode.Update => new WizardWindow
            {
                DataContext = _services.GetRequiredService<WizardViewModel>()
            },
            InstallerMode.Config => new SettingsWindow
            {
                DataContext = _services.GetRequiredService<SettingsViewModel>()
            },
            _ => throw new InvalidOperationException($"Unknown installer mode: {state.Mode}")
        };

        DarkTitleBar.Apply(mainWindow);
        mainWindow.Show();
    }

    protected override void OnExit(ExitEventArgs e)
    {
        _services?.Dispose();
        base.OnExit(e);
    }

    private static string GetInstallerVersion()
    {
        var infoAttr = Assembly.GetExecutingAssembly()
            .GetCustomAttribute<AssemblyInformationalVersionAttribute>();
        return infoAttr?.InformationalVersion ?? "0.0.0";
    }

    private static ServiceProvider BuildServices()
    {
        var sc = new ServiceCollection();

        // Core
        sc.AddSingleton<InstallContext>();
        sc.AddSingleton<PageResolver>();
        sc.AddSingleton<InstallerService>();

        // HTTP + release client
        sc.AddSingleton(_ => new HttpClient { Timeout = TimeSpan.FromSeconds(15) });
        sc.AddSingleton<IReleaseClient>(sp => new ReleaseClient(sp.GetRequiredService<HttpClient>()));
        sc.AddSingleton<InstallModeDetector>();

        // Pages
        sc.AddSingleton<IInstallerPage, WelcomePageViewModel>();
        sc.AddSingleton<IInstallerPage, PathsPageViewModel>();
        sc.AddSingleton<IInstallerPage, ServicePageViewModel>();
        sc.AddSingleton<IInstallerPage, UiSettingsPageViewModel>();
        sc.AddSingleton<IInstallerPage, InstallPageViewModel>();

        // Steps — execution order matters. InstallerService composes per-mode
        // step lists from this DI set (see WizardViewModel).
        sc.AddSingleton<IInstallStep, DownloadAndExtractStep>();
        sc.AddSingleton<IInstallStep, WriteConfigStep>();
        sc.AddSingleton<IInstallStep, InitDatabaseStep>();
        sc.AddSingleton<IInstallStep, RegisterServiceStep>();
        sc.AddSingleton<IInstallStep, CreateShortcutsStep>();
        sc.AddSingleton<IInstallStep, WriteInstallManifestStep>();
        sc.AddSingleton<StopServiceStep>();
        sc.AddSingleton<StartServiceStep>();

        // ViewModels
        sc.AddSingleton<WizardViewModel>();
        sc.AddSingleton<SettingsViewModel>();

        return sc.BuildServiceProvider();
    }
}
```

Notes on the DI list:

- `IInstallStep` registrations are the **fresh-install** order: download → write config → init DB → register service → create shortcuts → write manifest.
- `StopServiceStep` / `StartServiceStep` are registered as concrete types (not `IInstallStep`) so they don't appear in the default fresh-install pipeline — they're pulled out explicitly for the Update and Uninstall flows.

- [ ] **Step 2: Build**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: Build succeeds.

- [ ] **Step 3: Run the app and verify it starts**

Run: `dotnet run --project src/ClaudeDo.Installer`
Expected: Installer launches. On a machine without `install.json` at `C:\Program Files\ClaudeDo` it shows the fresh-install wizard (currently still referencing `SourceDirectory` UI — that's broken-by-design until Task 12).

Verification: it doesn't crash on startup. If it does, the typical cause is `InstallModeDetector` blocking on DI. Fix before proceeding.

- [ ] **Step 4: Commit**

```bash
git add src/ClaudeDo.Installer/App.xaml.cs
git commit -m "feat(installer): async mode detection + mode-aware DI wiring"
```

---

## Task 12: Rewrite `WelcomePageViewModel` (no source dir, mode-aware)

**Files:**
- Modify: `src/ClaudeDo.Installer/Pages/WelcomePage/WelcomePageViewModel.cs`
- Modify: `src/ClaudeDo.Installer/Pages/WelcomePage/WelcomePageView.xaml`

- [ ] **Step 1: Replace the view-model**

Fully replace `src/ClaudeDo.Installer/Pages/WelcomePage/WelcomePageViewModel.cs` with:

```csharp
using System.IO;
using System.Windows.Controls;
using ClaudeDo.Installer.Core;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using Microsoft.Win32;

namespace ClaudeDo.Installer.Pages.WelcomePage;

public partial class WelcomePageViewModel : ObservableObject, IInstallerPage
{
    private readonly InstallContext _context;
    private WelcomePageView? _view;

    public string Title => "Welcome";
    public string Icon => "\uE80F";
    public int Order => 0;
    public bool ShowInWizard => true;
    public bool ShowInSettings => false;
    public UserControl View => _view ??= new WelcomePageView { DataContext = this };

    [ObservableProperty] private string _installDirectory = @"C:\Program Files\ClaudeDo";
    [ObservableProperty] private string? _installError;
    [ObservableProperty] private string _heading = "Install ClaudeDo";
    [ObservableProperty] private string _subheading = "Set the installation directory and continue.";
    [ObservableProperty] private bool _installDirEditable = true;

    public WelcomePageViewModel(InstallContext context)
    {
        _context = context;
    }

    public Task LoadAsync()
    {
        InstallDirectory = string.IsNullOrEmpty(_context.InstallDirectory)
            ? @"C:\Program Files\ClaudeDo"
            : _context.InstallDirectory;

        switch (_context.Mode)
        {
            case InstallerMode.FreshInstall:
                Heading = "Install ClaudeDo";
                Subheading = "Choose where to install ClaudeDo, then click Next.";
                InstallDirEditable = true;
                break;

            case InstallerMode.Update:
                Heading = $"Update ClaudeDo  {_context.InstalledVersion}  ->  {_context.LatestVersion}";
                Subheading = "Your tasks, config, and database will be preserved. Click Next to continue.";
                InstallDirEditable = false; // stay where we were installed
                break;
        }

        return Task.CompletedTask;
    }

    public Task ApplyAsync()
    {
        _context.InstallDirectory = InstallDirectory;
        return Task.CompletedTask;
    }

    public bool Validate()
    {
        if (string.IsNullOrWhiteSpace(InstallDirectory))
        {
            InstallError = "Install directory is required";
            return false;
        }
        InstallError = null;
        return true;
    }

    [RelayCommand]
    private void BrowseInstall()
    {
        if (!InstallDirEditable) return;
        var dialog = new OpenFolderDialog { Title = "Select installation directory" };
        if (dialog.ShowDialog() == true)
            InstallDirectory = dialog.FolderName;
    }
}
```

- [ ] **Step 2: Update the XAML**

Open `src/ClaudeDo.Installer/Pages/WelcomePage/WelcomePageView.xaml`. Replace the two source-directory inputs with a single install-directory input, and surface `Heading` / `Subheading` as bound labels. The exact layout matches the existing styling — just remove the Source section and keep Install Directory. Here's a minimal replacement for the body (keep the existing namespace/Resources/outer `<UserControl>`):

```xml
<StackPanel Margin="24,16" Orientation="Vertical">

    <TextBlock Text="{Binding Heading}" FontSize="20" FontWeight="SemiBold" Margin="0,0,0,6"/>
    <TextBlock Text="{Binding Subheading}" TextWrapping="Wrap" Opacity="0.7" Margin="0,0,0,24"/>

    <TextBlock Text="Install Directory" Margin="0,0,0,4"/>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="Auto"/>
        </Grid.ColumnDefinitions>
        <TextBox Grid.Column="0"
                 Text="{Binding InstallDirectory, UpdateSourceTrigger=PropertyChanged}"
                 IsEnabled="{Binding InstallDirEditable}"/>
        <Button Grid.Column="1"
                Content="Browse..."
                Margin="8,0,0,0"
                Command="{Binding BrowseInstallCommand}"
                IsEnabled="{Binding InstallDirEditable}"/>
    </Grid>
    <TextBlock Text="{Binding InstallError}" Foreground="#F77" Margin="0,4,0,0"
               Visibility="{Binding InstallError, Converter={StaticResource NullToCollapsedConverter}}"/>

</StackPanel>
```

- [ ] **Step 3: Build**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: Build succeeds.

- [ ] **Step 4: Manual smoke-test fresh-install flow**

Run: `dotnet run --project src/ClaudeDo.Installer`

Expected:
- Installer launches into WizardWindow (no `install.json` exists anywhere yet).
- Welcome page shows "Install ClaudeDo" with one install-directory input.
- Clicking Next advances to PathsPage without errors.

Click through: Welcome → Paths → Service → UiSettings → Install. Do NOT click Install (the download step would actually try to hit Gitea — that's Task 17 territory). Just confirm navigation works. Close the window.

- [ ] **Step 5: Commit**

```bash
git add src/ClaudeDo.Installer/Pages/WelcomePage
git commit -m "feat(installer): rewrite WelcomePage for download-mode + update heading"
```

---

## Task 13: Config view — add Repair + Uninstall commands

**Files:**
- Modify: `src/ClaudeDo.Installer/Views/SettingsViewModel.cs`
- Modify: `src/ClaudeDo.Installer/Views/SettingsWindow.xaml`

Add `RepairCommand` and `UninstallCommand` to the existing `SettingsViewModel`. The actual uninstall logic is in Task 14 — this task just wires the UI and plumbs through `InstallerService`.

- [ ] **Step 1: Extend `SettingsViewModel`**

Open `src/ClaudeDo.Installer/Views/SettingsViewModel.cs` and replace its contents with:

```csharp
using System.Windows;
using ClaudeDo.Installer.Core;
using ClaudeDo.Installer.Steps;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;

namespace ClaudeDo.Installer.Views;

public partial class SettingsViewModel : ObservableObject
{
    private readonly InstallContext _context;
    private readonly IReleaseClient _releases;
    private readonly StopServiceStep _stopService;

    public IReadOnlyList<IInstallerPage> Pages { get; }

    [ObservableProperty]
    private IInstallerPage? _selectedPage;

    [ObservableProperty]
    private string? _statusMessage;

    [ObservableProperty]
    private bool _isStatusError;

    [ObservableProperty]
    private string _versionLabel = "";

    public SettingsViewModel(
        PageResolver resolver,
        InstallContext context,
        IReleaseClient releases,
        StopServiceStep stopService)
    {
        Pages = resolver.SettingsPages;
        _context = context;
        _releases = releases;
        _stopService = stopService;
        _selectedPage = Pages.FirstOrDefault();

        VersionLabel = $"Installed: {context.InstalledVersion ?? "?"}   Installer: {context.InstallerVersion ?? "?"}";

        _ = LoadAllAsync();
    }

    private async Task LoadAllAsync()
    {
        foreach (var page in Pages)
            await page.LoadAsync();
    }

    [RelayCommand]
    private async Task Save()
    {
        foreach (var page in Pages)
        {
            if (!page.Validate())
            {
                SelectedPage = page;
                StatusMessage = $"Validation failed on {page.Title}. Please fix the errors.";
                IsStatusError = true;
                return;
            }
        }

        foreach (var page in Pages)
            await page.ApplyAsync();

        var workerCfg = new InstallerWorkerConfig
        {
            DbPath = _context.DbPath,
            SandboxRoot = _context.SandboxRoot,
            LogRoot = _context.LogRoot,
            WorktreeRootStrategy = _context.WorktreeRootStrategy,
            CentralWorktreeRoot = _context.CentralWorktreeRoot,
            QueueBackstopIntervalMs = _context.QueueBackstopIntervalMs,
            SignalRPort = _context.SignalRPort,
            ClaudeBin = _context.ClaudeBin,
        };
        workerCfg.Save();

        var uiCfg = new InstallerAppSettings
        {
            DbPath = _context.UiDbPath,
            SignalRUrl = _context.SignalRUrl,
        };
        uiCfg.Save();

        StatusMessage = "Settings saved.";
        IsStatusError = false;
    }

    [RelayCommand]
    private async Task Repair()
    {
        var result = MessageBox.Show(
            "Re-download and reinstall the ClaudeDo binaries? Your config and database are NOT affected.",
            "Repair ClaudeDo",
            MessageBoxButton.OKCancel,
            MessageBoxImage.Question);

        if (result != MessageBoxResult.OK) return;

        StatusMessage = "Repairing... (this window will close when done)";
        IsStatusError = false;

        // Delegate to the standard Update pipeline: stop service -> download -> start service.
        var step1 = _stopService;
        var step2 = new DownloadAndExtractStep(_releases);
        var step3 = new Steps.StartServiceStep();
        var progress = new Progress<string>(msg => StatusMessage = msg);

        foreach (var step in new IInstallStep[] { step1, step2, step3 })
        {
            var r = await step.ExecuteAsync(_context, progress, CancellationToken.None);
            if (!r.Success)
            {
                StatusMessage = $"{step.Name} failed: {r.ErrorMessage}";
                IsStatusError = true;
                return;
            }
        }

        StatusMessage = "Repair complete.";
    }

    [RelayCommand]
    private async Task Uninstall()
    {
        // Full-removal confirmation. Uninstall logic lives in UninstallRunner (next task).
        var result = MessageBox.Show(
            "This will remove ClaudeDo AND delete all of your tasks, configuration, and database.\n\nContinue?",
            "Uninstall ClaudeDo",
            MessageBoxButton.YesNo,
            MessageBoxImage.Warning);

        if (result != MessageBoxResult.Yes) return;

        var progress = new Progress<string>(msg => StatusMessage = msg);
        var runner = new UninstallRunner(_context, _stopService);
        var r = await runner.RunAsync(progress, CancellationToken.None);

        if (!r.Success)
        {
            StatusMessage = $"Uninstall failed: {r.ErrorMessage}";
            IsStatusError = true;
            return;
        }

        MessageBox.Show("ClaudeDo has been removed.", "Uninstall complete",
            MessageBoxButton.OK, MessageBoxImage.Information);
        Application.Current.Shutdown();
    }

    [RelayCommand]
    private void Close() => Application.Current.Shutdown();
}
```

- [ ] **Step 2: Add Repair + Uninstall buttons to `SettingsWindow.xaml`**

Open `src/ClaudeDo.Installer/Views/SettingsWindow.xaml` and add three buttons to the bottom action row, replacing any existing Apply/Cancel pair. The existing `Apply` rename to `Save` (bind to `SaveCommand`). Example for the footer:

```xml
<Grid Grid.Row="2" Margin="16,12">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto"/>
    </Grid.ColumnDefinitions>

    <TextBlock Grid.Column="0" Text="{Binding VersionLabel}" VerticalAlignment="Center" Opacity="0.7"/>

    <Button Grid.Column="1" Content="Uninstall" Margin="0,0,8,0"
            Command="{Binding UninstallCommand}"/>
    <Button Grid.Column="2" Content="Repair" Margin="0,0,8,0"
            Command="{Binding RepairCommand}"/>
    <Button Grid.Column="3" Content="Save" Margin="0,0,8,0"
            Command="{Binding SaveCommand}"/>
    <Button Grid.Column="4" Content="Close"
            Command="{Binding CloseCommand}"/>
</Grid>
```

(Keep the existing content area and status message rows; only the footer grid changes.)

- [ ] **Step 3: Build**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: FAIL — `UninstallRunner` is referenced but doesn't exist yet. That's Task 14. Keep the error visible so the next commit lands cleanly.

- [ ] **Step 4: Commit the VM + XAML changes (compile-broken is OK — noted in msg)**

```bash
git add src/ClaudeDo.Installer/Views
git commit -m "feat(installer): add Repair/Uninstall commands + Save/Close UI to Config view"
```

---

## Task 14: Uninstall runner (service teardown + filesystem cleanup)

**Files:**
- Create: `src/ClaudeDo.Installer/Core/UninstallRunner.cs`

- [ ] **Step 1: Implement the runner**

Create `src/ClaudeDo.Installer/Core/UninstallRunner.cs`:

```csharp
using System.IO;
using ClaudeDo.Data;
using ClaudeDo.Installer.Steps;

namespace ClaudeDo.Installer.Core;

public sealed class UninstallRunner
{
    private const string ServiceName = "ClaudeDoWorker";

    private readonly InstallContext _context;
    private readonly StopServiceStep _stopService;

    public UninstallRunner(InstallContext context, StopServiceStep stopService)
    {
        _context = context;
        _stopService = stopService;
    }

    public async Task<StepResult> RunAsync(IProgress<string> progress, CancellationToken ct)
    {
        // 1) Stop + delete service.
        progress.Report("Stopping worker service...");
        var stopResult = await _stopService.ExecuteAsync(_context, progress, ct);
        if (!stopResult.Success)
        {
            // Don't bail — service may already be gone. Log and continue.
            progress.Report($"(Ignored) {stopResult.ErrorMessage}");
        }

        progress.Report("Unregistering service...");
        await ProcessRunner.RunAsync("sc.exe", $"delete {ServiceName}", null, progress, ct);

        // 2) Remove shortcuts.
        progress.Report("Removing shortcuts...");
        TryDeleteFile(Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.CommonDesktopDirectory),
            "ClaudeDo.lnk"));
        TryDeleteFile(Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.CommonStartMenu),
            "Programs", "ClaudeDo.lnk"));

        // 3) Delete install directory.
        if (Directory.Exists(_context.InstallDirectory))
        {
            progress.Report($"Deleting {_context.InstallDirectory}...");
            TryDeleteDir(_context.InstallDirectory);
        }

        // 4) Delete ~/.todo-app (config + DB + logs).
        var appData = Paths.AppDataRoot();
        if (Directory.Exists(appData))
        {
            progress.Report($"Deleting {appData}...");
            TryDeleteDir(appData);
        }

        progress.Report("Uninstall complete.");
        return StepResult.Ok();
    }

    private static void TryDeleteFile(string path)
    {
        try { if (File.Exists(path)) File.Delete(path); } catch { /* best effort */ }
    }

    private static void TryDeleteDir(string path)
    {
        try { Directory.Delete(path, recursive: true); } catch { /* best effort */ }
    }
}
```

Note: `Paths.AppDataRoot()` comes from `ClaudeDo.Data` (already referenced in the installer csproj) — same helper the existing `ModeDetector` used.

- [ ] **Step 2: Build**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: Build succeeds (Task 13's reference to `UninstallRunner` now resolves).

- [ ] **Step 3: Commit**

```bash
git add src/ClaudeDo.Installer/Core/UninstallRunner.cs
git commit -m "feat(installer): add UninstallRunner (service + shortcuts + dirs)"
```

---

## Task 15: Teach `WizardViewModel` about Update mode

The fresh-install wizard runs all pages in order. Update mode should **skip** Paths/UiSettings/Service (config already exists) and jump Welcome → Install directly.

**Files:**
- Modify: `src/ClaudeDo.Installer/Views/WizardViewModel.cs`
- Modify: `src/ClaudeDo.Installer/Core/InstallerService.cs`

- [ ] **Step 1: Add a `Mode`-aware page filter to `WizardViewModel`**

Replace the `Pages` initialization in `WizardViewModel` constructor to filter based on `context.Mode`. Open `src/ClaudeDo.Installer/Views/WizardViewModel.cs` and change the constructor + `Pages` property:

```csharp
public WizardViewModel(PageResolver resolver, InstallContext context)
{
    _context = context;

    var all = resolver.WizardPages;
    Pages = context.Mode == InstallerMode.Update
        ? all.Where(p => p is Pages.WelcomePage.WelcomePageViewModel
                      || p is Pages.InstallPage.InstallPageViewModel).ToList()
        : all;

    if (Pages.Count > 0)
        _ = InitAsync();
}
```

- [ ] **Step 2: Teach `InstallerService` about the Update step list**

The fresh-install step list already lives in DI registration order. For Update mode we only run: `StopServiceStep` → `DownloadAndExtractStep` → `StartServiceStep` → `WriteInstallManifestStep`. The simplest change is in `InstallPageViewModel` — not `InstallerService` itself — because that's where the step pipeline is kicked off. Check that file's current step invocation: if it iterates `IEnumerable<IInstallStep>` from DI, it already picks up the list correctly for Fresh-install mode.

For Update mode, `InstallPageViewModel` should instead pull explicit steps. Since I haven't shown you that file yet, read it first:

Run: `cat src/ClaudeDo.Installer/Pages/InstallPage/InstallPageViewModel.cs`

Expected structure: the VM calls `InstallerService.ExecuteAsync(...)` once. Adjust it so:

```csharp
// Inside InstallPageViewModel.ExecuteInstallCommand or similar
var steps = _context.Mode == InstallerMode.Update
    ? new IInstallStep[]
    {
        _serviceProvider.GetRequiredService<StopServiceStep>(),
        _serviceProvider.GetRequiredService<DownloadAndExtractStep>(),
        _serviceProvider.GetRequiredService<StartServiceStep>(),
        _serviceProvider.GetRequiredService<WriteInstallManifestStep>(),
    }
    : _allSteps; // existing IEnumerable<IInstallStep> from DI

var runner = new InstallerService(steps);
await runner.ExecuteAsync(_context, progress, ct);
```

To do this you'll need to inject `IServiceProvider` into `InstallPageViewModel` (add `IServiceProvider` to its ctor) and register `DownloadAndExtractStep`, `WriteInstallManifestStep`, `StopServiceStep`, `StartServiceStep` as **both** concrete types and `IInstallStep` (the `Singleton` lifetime ensures they resolve to the same instance). Adjust `App.xaml.cs` DI registration:

```csharp
sc.AddSingleton<DownloadAndExtractStep>();
sc.AddSingleton<IInstallStep>(sp => sp.GetRequiredService<DownloadAndExtractStep>());
sc.AddSingleton<WriteInstallManifestStep>();
sc.AddSingleton<IInstallStep>(sp => sp.GetRequiredService<WriteInstallManifestStep>());
// StopServiceStep + StartServiceStep are registered as concrete only (already in Task 11).
```

Apply the same double-registration pattern to any other IInstallStep you need to reference by concrete type.

- [ ] **Step 3: Build**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: Build succeeds.

- [ ] **Step 4: Commit**

```bash
git add src/ClaudeDo.Installer
git commit -m "feat(installer): mode-aware wizard page list + Update-mode step pipeline"
```

---

## Task 16: csproj publish properties for single-file self-contained

**Files:**
- Modify: `src/ClaudeDo.Installer/ClaudeDo.Installer.csproj`

- [ ] **Step 1: Add publish-time defaults**

Add (not replace) a `PropertyGroup` scoped to publish in `src/ClaudeDo.Installer/ClaudeDo.Installer.csproj`:

```xml
  <PropertyGroup Condition="'$(PublishSingleFile)' == 'true'">
    <PublishTrimmed>false</PublishTrimmed>
    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
    <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract>
    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
  </PropertyGroup>
```

These only apply when `dotnet publish /p:PublishSingleFile=true` is passed (as the workflow does). Debug/Release desktop builds aren't affected.

- [ ] **Step 2: Build check**

Run: `dotnet build src/ClaudeDo.Installer`
Expected: succeeds.

- [ ] **Step 3: Publish-test locally (optional but recommended)**

Run: `dotnet publish src/ClaudeDo.Installer -c Release -r win-x64 --self-contained true /p:Version=0.0.0-test /p:PublishSingleFile=true -o out/installer-test`

Verify `out/installer-test/ClaudeDo.Installer.exe` exists and is standalone (single large exe, no DLLs next to it aside from unavoidable ones like PresentationCore native runtimes — that's expected for WPF).

- [ ] **Step 4: Commit**

```bash
git add src/ClaudeDo.Installer/ClaudeDo.Installer.csproj
git commit -m "build(installer): add single-file self-contained publish properties"
```

---

## Task 17: Full build + manual end-to-end smoke

All code is in. The actual Gitea release workflow may or may not be running yet — doesn't matter for local verification because the installer can be pointed at any Gitea instance.

- [ ] **Step 1: Full build**

Run: `dotnet build ClaudeDo.slnx`
Expected: All 6 projects build.

- [ ] **Step 2: Full test run**

Run: `dotnet test ClaudeDo.slnx`
Expected: All tests pass. The Installer.Tests project should show ~20 passing tests.

- [ ] **Step 3: Manual fresh-install smoke (skip the actual download)**

Publish and run the installer in "test" mode. Since there's no real release yet, you can either:
- (a) Skip until the VPS workflow has published v0.0.0-test, then run the real installer, OR
- (b) Stand up a local fake: run a tiny static file server on `localhost:5000` serving a handcrafted release zip + checksums, and point the installer at it by overriding `ReleaseClient.DefaultApiBase` (add a CLI arg for this if you want).

Recommended: (a). Coordinate with the VPS-side Claude when their workflow is ready.

- [ ] **Step 4: Manual Config/Uninstall smoke**

Place a fake `install.json` at `C:\Program Files\ClaudeDo\install.json`:

```json
{
  "version": "9.9.9",
  "installDir": "C:\\Program Files\\ClaudeDo",
  "workerDir": "C:\\Program Files\\ClaudeDo\\worker",
  "installedAt": "2026-04-15T12:00:00Z"
}
```

Run the installer. Expected: it opens SettingsWindow (Config mode) because `9.9.9` is newer than any real release.

Click `Save` with no changes → status "Settings saved."
Click `Uninstall` → confirmation → everything deletes. (**Run on a throwaway machine or adjust paths** — this really does remove `~/.todo-app`.)

- [ ] **Step 5: Push the branch**

```bash
git push -u origin feat/installer
```

Expected: branch pushed to `releases/ClaudeDo` on `git.kuns.dev`. Open a PR there (or merge directly on main if you're the only user — your call).

---

## Self-Review Notes

**Spec coverage:**
- Release artifacts layout → covered by the workflow (not this plan's scope).
- `install.json` marker → Task 2 + 8.
- Mode detection (Fresh / Update / Config) → Task 5 + 11 + 15.
- `DownloadAndExtractStep` (API + checksum + extract) → Task 7.
- Service stop/start on update → Task 6 + 15.
- Config view Save/Repair/Uninstall → Task 13 + 14.
- Uninstall removes InstallDir + `~/.todo-app` → Task 14.
- Old publish/deploy steps deleted → Task 9.
- Self-contained installer published single-file → Task 16.
- Offline = not fatal (Config still opens) → Task 5 test + Task 11 CTS timeout.
- Checksum mismatch = no mutation of InstallDir → Task 7 test.

**Placeholder scan:** No TBDs, no "add appropriate error handling"-style lines. Every TDD task contains the exact test + implementation.

**Type consistency:** `InstallerMode.FreshInstall` / `Update` / `Config` used everywhere. `InstallContext.InstalledVersion` set in Task 7 (step runtime) AND Task 11 (startup). `IReleaseClient` interface used by detector + download step + settings VM. `StopServiceStep` / `StartServiceStep` spelled identically across tasks.

**Gap I noticed during review:** Task 13's `RepairCommand` constructs a new `DownloadAndExtractStep(_releases)` and a new `StartServiceStep()` inline rather than resolving them from DI. That's fine functionally (they have cheap constructors), but if `DownloadAndExtractStep` grows dependencies later, switch to DI. Leaving as-is.
