feat(worker,data): add git worktree support and conventional commits

GitService (in ClaudeDo.Data so the UI can reuse it) wraps the git CLI:
IsGitRepo, RevParseHead, WorktreeAdd/Remove, HasChanges, AddAll, Commit
(multi-line via -F -), DiffStat, BranchDelete, MergeFfOnly. Throws with
stderr on failure.

WorktreeManager owns the per-task lifecycle: validate working_dir is a
git repo (throws if not, no DB row written), create the worktree at
<repo>/../.claudedo-worktrees/<slug>/<id>/ (or central root per config),
insert the worktrees row. CommitIfChangedAsync skips when there are no
changes, otherwise commits and updates head_commit + diff_stat.

CommitMessageBuilder produces "{type}({list-slug}): {title<=60}" with a
blank-line-separated description (truncated to 400) and a permanent
"ClaudeDo-Task: <id>" trailer. Slug normalises whitespace + strips
non-alphanumerics. Newlines hard-coded to \n so git on Windows doesn't
choke on \r\n.

TaskRunner branches on list.WorkingDir: worktree path runs Claude in the
worktree, commits on success, broadcasts WorktreeUpdated; failure leaves
the worktree row active for inspection. Sandbox path unchanged.

Tests: 38 pass (12 new). GitRepoFixture spins up a real temp repo with a
seed commit; tests skip gracefully if `git` isn't on PATH.
CommitMessageBuilder fully unit-tested. WorktreeManager covers create,
no-change skip, real-commit, and non-repo failure.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Data/Git/GitService.cs

@@ -0,0 +1,123 @@
+using System.Diagnostics;
+using System.Text;
+
+namespace ClaudeDo.Data.Git;
+
+public sealed class GitService
+{
+    public async Task<bool> IsGitRepoAsync(string dir, CancellationToken ct = default)
+    {
+        var (exitCode, _, _) = await RunGitAsync(dir, ["rev-parse", "--git-dir"], ct);
+        return exitCode == 0;
+    }
+
+    public async Task<string> RevParseHeadAsync(string dir, CancellationToken ct = default)
+    {
+        var (exitCode, stdout, stderr) = await RunGitAsync(dir, ["rev-parse", "HEAD"], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git rev-parse HEAD failed (exit {exitCode}): {stderr}");
+        return stdout.Trim();
+    }
+
+    public async Task WorktreeAddAsync(string repoDir, string branchName, string worktreePath, string baseCommit, CancellationToken ct = default)
+    {
+        var (exitCode, _, stderr) = await RunGitAsync(repoDir,
+            ["worktree", "add", "-b", branchName, worktreePath, baseCommit], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git worktree add failed (exit {exitCode}): {stderr}");
+    }
+
+    public async Task<bool> HasChangesAsync(string worktreePath, CancellationToken ct = default)
+    {
+        var (exitCode, stdout, stderr) = await RunGitAsync(worktreePath, ["status", "--porcelain"], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git status --porcelain failed (exit {exitCode}): {stderr}");
+        return !string.IsNullOrWhiteSpace(stdout);
+    }
+
+    public async Task AddAllAsync(string worktreePath, CancellationToken ct = default)
+    {
+        var (exitCode, _, stderr) = await RunGitAsync(worktreePath, ["add", "-A"], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git add -A failed (exit {exitCode}): {stderr}");
+    }
+
+    public async Task CommitAsync(string worktreePath, string message, CancellationToken ct = default)
+    {
+        // Use -F - (read message from stdin) to handle multi-line messages safely.
+        var (exitCode, _, stderr) = await RunGitAsync(worktreePath, ["commit", "-F", "-"], ct, stdinData: message);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git commit failed (exit {exitCode}): {stderr}");
+    }
+
+    public async Task<string> DiffStatAsync(string worktreePath, string baseCommit, string headCommit, CancellationToken ct = default)
+    {
+        var (exitCode, stdout, stderr) = await RunGitAsync(worktreePath,
+            ["diff", "--stat", $"{baseCommit}..{headCommit}"], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git diff --stat failed (exit {exitCode}): {stderr}");
+        return stdout.Trim();
+    }
+
+    public async Task WorktreeRemoveAsync(string repoDir, string worktreePath, bool force = false, CancellationToken ct = default)
+    {
+        var args = new List<string> { "worktree", "remove" };
+        if (force) args.Add("--force");
+        args.Add(worktreePath);
+
+        var (exitCode, _, stderr) = await RunGitAsync(repoDir, args, ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git worktree remove failed (exit {exitCode}): {stderr}");
+    }
+
+    public async Task BranchDeleteAsync(string repoDir, string branchName, bool force = false, CancellationToken ct = default)
+    {
+        var flag = force ? "-D" : "-d";
+        var (exitCode, _, stderr) = await RunGitAsync(repoDir, ["branch", flag, branchName], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git branch {flag} failed (exit {exitCode}): {stderr}");
+    }
+
+    public async Task MergeFfOnlyAsync(string repoDir, string branchName, CancellationToken ct = default)
+    {
+        var (exitCode, _, stderr) = await RunGitAsync(repoDir, ["merge", "--ff-only", branchName], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"Fast-forward merge of '{branchName}' failed. Manual merge required. git stderr: {stderr}");
+    }
+
+    private static async Task<(int ExitCode, string Stdout, string Stderr)> RunGitAsync(
+        string workDir, IEnumerable<string> args, CancellationToken ct, string? stdinData = null)
+    {
+        var psi = new ProcessStartInfo
+        {
+            FileName = "git",
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            RedirectStandardInput = stdinData is not null,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+        psi.ArgumentList.Add("-C");
+        psi.ArgumentList.Add(workDir);
+        foreach (var a in args) psi.ArgumentList.Add(a);
+
+        using var proc = new Process { StartInfo = psi };
+        proc.Start();
+
+        if (stdinData is not null)
+        {
+            await proc.StandardInput.WriteAsync(stdinData.AsMemory(), ct);
+            proc.StandardInput.Close();
+        }
+
+        var stdoutTask = proc.StandardOutput.ReadToEndAsync(ct);
+        var stderrTask = proc.StandardError.ReadToEndAsync(ct);
+
+        await proc.WaitForExitAsync(ct);
+
+        var stdout = await stdoutTask;
+        var stderr = await stderrTask;
+
+        return (proc.ExitCode, stdout.TrimEnd(), stderr.TrimEnd());
+    }
+}

src/ClaudeDo.Worker/Program.cs

@@ -1,4 +1,5 @@
 using ClaudeDo.Data;
+using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Config;
 using ClaudeDo.Worker.Hub;
@@ -25,6 +26,8 @@ builder.Services.AddSignalR();
 // Runner stack.
 builder.Services.AddSingleton<IClaudeProcess, ClaudeProcess>();
 builder.Services.AddSingleton<HubBroadcaster>();
+builder.Services.AddSingleton<GitService>();
+builder.Services.AddSingleton<WorktreeManager>();
 builder.Services.AddSingleton<TaskRunner>();
 
 // QueueService: singleton + hosted service (same instance).

src/ClaudeDo.Worker/Runner/CommitMessageBuilder.cs

@@ -0,0 +1,46 @@
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace ClaudeDo.Worker.Runner;
+
+public static class CommitMessageBuilder
+{
+    public static string Build(string commitType, string listName, string taskTitle, string? taskDescription, string taskId)
+    {
+        var slug = ToSlug(listName);
+        var title = Truncate(taskTitle, 60);
+        var header = $"{commitType}({slug}): {title}";
+
+        var sb = new StringBuilder();
+        sb.Append(header);
+
+        var hasDescription = !string.IsNullOrWhiteSpace(taskDescription);
+        if (hasDescription)
+        {
+            sb.Append("\n\n");
+            sb.Append(Truncate(taskDescription!.Trim(), 400));
+        }
+
+        // Trailer is always included.
+        sb.Append("\n\n");
+        sb.Append($"ClaudeDo-Task: {taskId}");
+
+        return sb.ToString();
+    }
+
+    public static string ToSlug(string name)
+    {
+        var lower = name.ToLowerInvariant();
+        // Replace whitespace runs with a single dash.
+        var dashed = Regex.Replace(lower, @"\s+", "-");
+        // Remove all non-alphanumeric-and-dash characters.
+        var cleaned = Regex.Replace(dashed, @"[^a-z0-9\-]", "");
+        // Collapse multiple dashes.
+        var collapsed = Regex.Replace(cleaned, @"-{2,}", "-");
+        // Trim leading/trailing dashes.
+        return collapsed.Trim('-');
+    }
+
+    private static string Truncate(string value, int maxLength) =>
+        value.Length <= maxLength ? value : value[..maxLength];
+}

src/ClaudeDo.Worker/Runner/TaskRunner.cs

@@ -10,6 +10,7 @@ public sealed class TaskRunner
     private readonly TaskRepository _taskRepo;
     private readonly ListRepository _listRepo;
     private readonly HubBroadcaster _broadcaster;
+    private readonly WorktreeManager _wtManager;
     private readonly WorkerConfig _cfg;
     private readonly ILogger<TaskRunner> _logger;
 
@@ -18,6 +19,7 @@ public sealed class TaskRunner
         TaskRepository taskRepo,
         ListRepository listRepo,
         HubBroadcaster broadcaster,
+        WorktreeManager wtManager,
         WorkerConfig cfg,
         ILogger<TaskRunner> logger)
     {
@@ -25,6 +27,7 @@ public sealed class TaskRunner
         _taskRepo = taskRepo;
         _listRepo = listRepo;
         _broadcaster = broadcaster;
+        _wtManager = wtManager;
         _cfg = cfg;
         _logger = logger;
     }
@@ -40,16 +43,30 @@ public sealed class TaskRunner
                 return;
             }
 
-            // Slice D: worktree mode not yet implemented.
+            // Determine working directory: worktree or sandbox.
+            WorktreeContext? wtCtx = null;
+            string runDir;
+
             if (list.WorkingDir is not null)
             {
-                await MarkFailed(task.Id, slot, "Worktree mode not implemented yet (Slice E)");
+                try
+                {
+                    wtCtx = await _wtManager.CreateAsync(task, list, ct);
+                    runDir = wtCtx.WorktreePath;
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Failed to create worktree for task {TaskId}", task.Id);
+                    await MarkFailed(task.Id, slot, $"Worktree creation failed: {ex.Message}");
                     return;
                 }
-
+            }
+            else
+            {
                 // Non-worktree sandbox path.
-            var sandboxDir = Path.Combine(_cfg.SandboxRoot, task.Id);
-            Directory.CreateDirectory(sandboxDir);
+                runDir = Path.Combine(_cfg.SandboxRoot, task.Id);
+                Directory.CreateDirectory(runDir);
+            }
 
             var logPath = Path.Combine(_cfg.LogRoot, $"{task.Id}.ndjson");
 
@@ -67,7 +84,7 @@ public sealed class TaskRunner
 
             var result = await _claude.RunAsync(
                 prompt,
-                sandboxDir,
+                runDir,
                 logPath,
                 task.Id,
                 async line =>
@@ -81,12 +98,21 @@ public sealed class TaskRunner
 
             if (result.IsSuccess)
             {
+                // Auto-commit if worktree mode and run succeeded.
+                if (wtCtx is not null)
+                {
+                    var committed = await _wtManager.CommitIfChangedAsync(wtCtx, task, list, ct);
+                    if (committed)
+                        await _broadcaster.WorktreeUpdated(task.Id);
+                }
+
                 await _taskRepo.MarkDoneAsync(task.Id, finishedAt, result.ResultMarkdown, ct);
                 await _broadcaster.TaskFinished(slot, task.Id, "done", finishedAt);
                 _logger.LogInformation("Task {TaskId} completed successfully", task.Id);
             }
             else
             {
+                // Failed run: do NOT commit. Worktree row stays active for inspection.
                 await _taskRepo.MarkFailedAsync(task.Id, finishedAt, result.ErrorMarkdown, ct);
                 await _broadcaster.TaskFinished(slot, task.Id, "failed", finishedAt);
                 _logger.LogWarning("Task {TaskId} failed: {Error}", task.Id, result.ErrorMarkdown);

src/ClaudeDo.Worker/Runner/WorktreeManager.cs

@@ -0,0 +1,93 @@
+using ClaudeDo.Data.Git;
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Config;
+
+namespace ClaudeDo.Worker.Runner;
+
+public sealed record WorktreeContext(string WorktreePath, string BranchName, string BaseCommit);
+
+public sealed class WorktreeManager
+{
+    private readonly GitService _git;
+    private readonly WorktreeRepository _wtRepo;
+    private readonly WorkerConfig _cfg;
+    private readonly ILogger<WorktreeManager> _logger;
+
+    public WorktreeManager(GitService git, WorktreeRepository wtRepo, WorkerConfig cfg, ILogger<WorktreeManager> logger)
+    {
+        _git = git;
+        _wtRepo = wtRepo;
+        _cfg = cfg;
+        _logger = logger;
+    }
+
+    public async Task<WorktreeContext> CreateAsync(TaskEntity task, ListEntity list, CancellationToken ct)
+    {
+        var workingDir = list.WorkingDir
+            ?? throw new InvalidOperationException("list.WorkingDir is null");
+
+        if (!await _git.IsGitRepoAsync(workingDir, ct))
+            throw new InvalidOperationException($"working_dir is not a git repository: {workingDir}");
+
+        var baseCommit = await _git.RevParseHeadAsync(workingDir, ct);
+        var shortId = task.Id.Length >= 8 ? task.Id[..8] : task.Id;
+        var branchName = $"claudedo/{shortId}";
+        var slug = CommitMessageBuilder.ToSlug(list.Name);
+
+        var worktreePath = _cfg.WorktreeRootStrategy.Equals("central", StringComparison.OrdinalIgnoreCase)
+            ? Path.Combine(_cfg.CentralWorktreeRoot, slug, task.Id)
+            : Path.Combine(Path.GetDirectoryName(workingDir)!, ".claudedo-worktrees", slug, task.Id);
+
+        worktreePath = Path.GetFullPath(worktreePath);
+
+        // Ensure parent directory exists.
+        Directory.CreateDirectory(Path.GetDirectoryName(worktreePath)!);
+
+        // Create the worktree (this also creates the directory).
+        await _git.WorktreeAddAsync(workingDir, branchName, worktreePath, baseCommit, ct);
+
+        // Insert worktrees row AFTER git succeeds — if git throws, no row is created.
+        await _wtRepo.AddAsync(new WorktreeEntity
+        {
+            TaskId = task.Id,
+            Path = worktreePath,
+            BranchName = branchName,
+            BaseCommit = baseCommit,
+            HeadCommit = null,
+            DiffStat = null,
+            State = WorktreeState.Active,
+            CreatedAt = DateTime.UtcNow,
+        }, ct);
+
+        _logger.LogInformation("Created worktree for task {TaskId} at {Path} (branch {Branch}, base {Base})",
+            task.Id, worktreePath, branchName, baseCommit);
+
+        return new WorktreeContext(worktreePath, branchName, baseCommit);
+    }
+
+    /// <returns>true if a commit was made; false if no changes.</returns>
+    public async Task<bool> CommitIfChangedAsync(WorktreeContext ctx, TaskEntity task, ListEntity list, CancellationToken ct)
+    {
+        if (!await _git.HasChangesAsync(ctx.WorktreePath, ct))
+        {
+            _logger.LogInformation("No changes in worktree for task {TaskId}, skipping commit", task.Id);
+            return false;
+        }
+
+        await _git.AddAllAsync(ctx.WorktreePath, ct);
+
+        var message = CommitMessageBuilder.Build(
+            task.CommitType, list.Name, task.Title, task.Description, task.Id);
+
+        await _git.CommitAsync(ctx.WorktreePath, message, ct);
+
+        var head = await _git.RevParseHeadAsync(ctx.WorktreePath, ct);
+        var diffStat = await _git.DiffStatAsync(ctx.WorktreePath, ctx.BaseCommit, head, ct);
+
+        await _wtRepo.UpdateHeadAsync(task.Id, head, diffStat, ct);
+
+        _logger.LogInformation("Committed changes for task {TaskId}: {Head}", task.Id, head);
+        return true;
+    }
+}

tests/ClaudeDo.Worker.Tests/Infrastructure/GitRepoFixture.cs

@@ -0,0 +1,90 @@
+using System.Diagnostics;
+
+namespace ClaudeDo.Worker.Tests.Infrastructure;
+
+public sealed class GitRepoFixture : IDisposable
+{
+    public string RepoDir { get; }
+    public string BaseCommit { get; }
+
+    public GitRepoFixture()
+    {
+        RepoDir = Path.Combine(Path.GetTempPath(), $"claudedo_gittest_{Guid.NewGuid():N}");
+        Directory.CreateDirectory(RepoDir);
+
+        RunGit(RepoDir, "init");
+        RunGit(RepoDir, "config", "user.name", "test");
+        RunGit(RepoDir, "config", "user.email", "test@example.com");
+
+        File.WriteAllText(Path.Combine(RepoDir, "README.md"), "# test repo");
+        RunGit(RepoDir, "add", "-A");
+        RunGit(RepoDir, "commit", "-m", "initial commit");
+
+        BaseCommit = RunGit(RepoDir, "rev-parse", "HEAD").Trim();
+    }
+
+    public void Dispose()
+    {
+        try
+        {
+            // Force-remove read-only .git objects on Windows.
+            ForceDeleteDirectory(RepoDir);
+        }
+        catch { /* best effort */ }
+    }
+
+    public static bool IsGitAvailable()
+    {
+        try
+        {
+            var psi = new ProcessStartInfo("git", "--version")
+            {
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                UseShellExecute = false,
+                CreateNoWindow = true,
+            };
+            using var p = Process.Start(psi)!;
+            p.WaitForExit(5000);
+            return p.ExitCode == 0;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    internal static string RunGit(string workDir, params string[] args)
+    {
+        var psi = new ProcessStartInfo("git")
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+        psi.ArgumentList.Add("-C");
+        psi.ArgumentList.Add(workDir);
+        foreach (var a in args) psi.ArgumentList.Add(a);
+
+        using var proc = Process.Start(psi)!;
+        var stdout = proc.StandardOutput.ReadToEnd();
+        var stderr = proc.StandardError.ReadToEnd();
+        proc.WaitForExit();
+
+        if (proc.ExitCode != 0)
+            throw new InvalidOperationException($"git {string.Join(' ', args)} failed: {stderr}");
+
+        return stdout;
+    }
+
+    private static void ForceDeleteDirectory(string path)
+    {
+        if (!Directory.Exists(path)) return;
+        foreach (var file in Directory.EnumerateFiles(path, "*", SearchOption.AllDirectories))
+        {
+            File.SetAttributes(file, FileAttributes.Normal);
+        }
+        Directory.Delete(path, true);
+    }
+}

tests/ClaudeDo.Worker.Tests/Runner/CommitMessageBuilderTests.cs

@@ -0,0 +1,77 @@
+using ClaudeDo.Worker.Runner;
+
+namespace ClaudeDo.Worker.Tests.Runner;
+
+public class CommitMessageBuilderTests
+{
+    [Fact]
+    public void Slug_FromListName()
+    {
+        Assert.Equal("lager-app", CommitMessageBuilder.ToSlug("Lager App"));
+    }
+
+    [Fact]
+    public void Slug_SpecialCharsStripped()
+    {
+        Assert.Equal("my-list", CommitMessageBuilder.ToSlug("My! @List#"));
+    }
+
+    [Fact]
+    public void Slug_CollapsesDashes()
+    {
+        Assert.Equal("a-b", CommitMessageBuilder.ToSlug("a   --  b"));
+    }
+
+    [Fact]
+    public void Slug_TrimsLeadingTrailingDashes()
+    {
+        Assert.Equal("abc", CommitMessageBuilder.ToSlug("--abc--"));
+    }
+
+    [Fact]
+    public void Title_TruncatedTo60()
+    {
+        var longTitle = new string('x', 80);
+        var msg = CommitMessageBuilder.Build("feat", "My List", longTitle, null, "task-id-123");
+        var header = msg.Split('\n')[0];
+        // Header format: feat(my-list): <60 chars>
+        var titlePart = header.Split(": ", 2)[1];
+        Assert.Equal(60, titlePart.Length);
+    }
+
+    [Fact]
+    public void NoDescription_TrailerStillPresent()
+    {
+        var msg = CommitMessageBuilder.Build("chore", "Test List", "do something", null, "abc-123");
+        var lines = msg.Split('\n');
+
+        // header \n \n trailer = 3 lines (no description block, just blank separator).
+        Assert.Equal(3, lines.Length);
+        Assert.Equal("chore(test-list): do something", lines[0]);
+        Assert.Equal("", lines[1]);
+        Assert.Equal("ClaudeDo-Task: abc-123", lines[2]);
+    }
+
+    [Fact]
+    public void WithDescription_IncludedAboveTrailer()
+    {
+        var msg = CommitMessageBuilder.Build("feat", "Lager App", "add scan", "Detailed description here", "id-456");
+        var lines = msg.Split('\n');
+
+        Assert.Equal("feat(lager-app): add scan", lines[0]);
+        Assert.Equal("", lines[1]); // blank after header
+        Assert.Equal("Detailed description here", lines[2]);
+        Assert.Equal("", lines[3]); // blank before trailer
+        Assert.Equal("ClaudeDo-Task: id-456", lines[4]);
+    }
+
+    [Fact]
+    public void Description_TruncatedTo400()
+    {
+        var longDesc = new string('d', 500);
+        var msg = CommitMessageBuilder.Build("fix", "X", "title", longDesc, "id");
+        var lines = msg.Split('\n');
+        // lines[2] is the description line.
+        Assert.Equal(400, lines[2].Length);
+    }
+}

tests/ClaudeDo.Worker.Tests/Runner/WorktreeManagerTests.cs

@@ -0,0 +1,186 @@
+using ClaudeDo.Data.Git;
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Config;
+using ClaudeDo.Worker.Runner;
+using ClaudeDo.Worker.Tests.Infrastructure;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace ClaudeDo.Worker.Tests.Runner;
+
+public class WorktreeManagerTests : IDisposable
+{
+    private readonly List<GitRepoFixture> _fixtures = new();
+    private readonly List<DbFixture> _dbFixtures = new();
+    private readonly List<string> _tempDirs = new();
+    private readonly List<(string repoDir, string wtPath)> _worktreeCleanups = new();
+
+    private static bool GitAvailable => GitRepoFixture.IsGitAvailable();
+
+    private GitRepoFixture CreateRepo()
+    {
+        var f = new GitRepoFixture();
+        _fixtures.Add(f);
+        return f;
+    }
+
+    private async Task<(WorktreeManager mgr, WorktreeRepository wtRepo)> CreateManagerAsync(
+        TaskEntity task, ListEntity list, string strategy = "sibling", string? centralRoot = null)
+    {
+        var db = new DbFixture();
+        _dbFixtures.Add(db);
+
+        // Seed the DB with list and task so FK constraints pass.
+        var listRepo = new ListRepository(db.Factory);
+        var taskRepo = new TaskRepository(db.Factory);
+        await listRepo.AddAsync(list);
+        await taskRepo.AddAsync(task);
+
+        var wtRepo = new WorktreeRepository(db.Factory);
+        var cfg = new WorkerConfig
+        {
+            WorktreeRootStrategy = strategy,
+        };
+        if (centralRoot is not null)
+            cfg.CentralWorktreeRoot = centralRoot;
+
+        var mgr = new WorktreeManager(
+            new GitService(), wtRepo, cfg, NullLogger<WorktreeManager>.Instance);
+        return (mgr, wtRepo);
+    }
+
+    [Fact]
+    public async Task CreateAsync_Succeeds_InGitRepo()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = CreateRepo();
+        var (task, list) = MakeEntities(repo.RepoDir);
+        var (mgr, wtRepo) = await CreateManagerAsync(task, list);
+
+        var ctx = await mgr.CreateAsync(task, list, CancellationToken.None);
+        _worktreeCleanups.Add((repo.RepoDir, ctx.WorktreePath));
+
+        Assert.NotNull(ctx);
+        Assert.True(Directory.Exists(ctx.WorktreePath));
+        Assert.Equal($"claudedo/{task.Id[..8]}", ctx.BranchName);
+        Assert.Equal(repo.BaseCommit, ctx.BaseCommit);
+
+        var row = await wtRepo.GetByTaskIdAsync(task.Id);
+        Assert.NotNull(row);
+        Assert.Equal(WorktreeState.Active, row!.State);
+        Assert.Equal(ctx.BaseCommit, row.BaseCommit);
+        Assert.Null(row.HeadCommit);
+    }
+
+    [Fact]
+    public async Task CommitIfChangedAsync_NoChanges_HeadCommitStaysNull()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = CreateRepo();
+        var (task, list) = MakeEntities(repo.RepoDir);
+        var (mgr, wtRepo) = await CreateManagerAsync(task, list);
+
+        var ctx = await mgr.CreateAsync(task, list, CancellationToken.None);
+        _worktreeCleanups.Add((repo.RepoDir, ctx.WorktreePath));
+
+        var committed = await mgr.CommitIfChangedAsync(ctx, task, list, CancellationToken.None);
+
+        Assert.False(committed);
+        var row = await wtRepo.GetByTaskIdAsync(task.Id);
+        Assert.Null(row!.HeadCommit);
+    }
+
+    [Fact]
+    public async Task CommitIfChangedAsync_WithNewFile_HeadCommitSet()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = CreateRepo();
+        var (task, list) = MakeEntities(repo.RepoDir);
+        var (mgr, wtRepo) = await CreateManagerAsync(task, list);
+
+        var ctx = await mgr.CreateAsync(task, list, CancellationToken.None);
+        _worktreeCleanups.Add((repo.RepoDir, ctx.WorktreePath));
+
+        File.WriteAllText(Path.Combine(ctx.WorktreePath, "hello.txt"), "hello world");
+
+        var committed = await mgr.CommitIfChangedAsync(ctx, task, list, CancellationToken.None);
+
+        Assert.True(committed);
+        var row = await wtRepo.GetByTaskIdAsync(task.Id);
+        Assert.NotNull(row!.HeadCommit);
+        Assert.NotEqual(ctx.BaseCommit, row.HeadCommit);
+        Assert.NotNull(row.DiffStat);
+        Assert.Contains("hello.txt", row.DiffStat);
+    }
+
+    [Fact]
+    public async Task CreateAsync_NonGitDir_Throws_NoRow()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var tmpDir = Path.Combine(Path.GetTempPath(), $"claudedo_nogit_{Guid.NewGuid():N}");
+        Directory.CreateDirectory(tmpDir);
+        _tempDirs.Add(tmpDir);
+
+        var (task, list) = MakeEntities(tmpDir);
+
+        var db = new DbFixture();
+        _dbFixtures.Add(db);
+        var listRepo = new ListRepository(db.Factory);
+        var taskRepo = new TaskRepository(db.Factory);
+        await listRepo.AddAsync(list);
+        await taskRepo.AddAsync(task);
+
+        var wtRepo = new WorktreeRepository(db.Factory);
+        var cfg = new WorkerConfig { WorktreeRootStrategy = "sibling" };
+        var mgr = new WorktreeManager(
+            new GitService(), wtRepo, cfg, NullLogger<WorktreeManager>.Instance);
+
+        var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+            () => mgr.CreateAsync(task, list, CancellationToken.None));
+        Assert.Contains("not a git repository", ex.Message);
+
+        var row = await wtRepo.GetByTaskIdAsync(task.Id);
+        Assert.Null(row);
+    }
+
+    private static (TaskEntity task, ListEntity list) MakeEntities(string workingDir)
+    {
+        var listId = Guid.NewGuid().ToString();
+        var taskId = Guid.NewGuid().ToString();
+        var task = new TaskEntity
+        {
+            Id = taskId,
+            ListId = listId,
+            Title = "test task",
+            Description = "a description",
+            CommitType = "chore",
+            CreatedAt = DateTime.UtcNow,
+        };
+        var list = new ListEntity
+        {
+            Id = listId,
+            Name = "Test List",
+            WorkingDir = workingDir,
+            CreatedAt = DateTime.UtcNow,
+        };
+        return (task, list);
+    }
+
+    public void Dispose()
+    {
+        foreach (var (repoDir, wtPath) in _worktreeCleanups)
+        {
+            try { GitRepoFixture.RunGit(repoDir, "worktree", "remove", "--force", wtPath); } catch { }
+        }
+        foreach (var f in _fixtures) f.Dispose();
+        foreach (var db in _dbFixtures) db.Dispose();
+        foreach (var d in _tempDirs)
+        {
+            try { Directory.Delete(d, true); } catch { }
+        }
+    }
+}

tests/ClaudeDo.Worker.Tests/Services/QueueServiceTests.cs

@@ -1,3 +1,4 @@
+using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Config;
@@ -46,7 +47,9 @@ public sealed class QueueServiceTests : IDisposable
     {
         var fake = new FakeClaudeProcess(handler);
         var broadcaster = new HubBroadcaster(new FakeHubContext());
-        var runner = new TaskRunner(fake, _taskRepo, _listRepo, broadcaster, _cfg,
+        var wtRepo = new WorktreeRepository(_db.Factory);
+        var wtManager = new WorktreeManager(new GitService(), wtRepo, _cfg, NullLogger<WorktreeManager>.Instance);
+        var runner = new TaskRunner(fake, _taskRepo, _listRepo, broadcaster, wtManager, _cfg,
             NullLogger<TaskRunner>.Instance);
         var service = new QueueService(_taskRepo, runner, _cfg, NullLogger<QueueService>.Instance);
         return (service, fake);