feat(branding): add app and installer icons

- app: ClaudeTask.ico wired as ApplicationIcon and MainWindow.Icon
  via avares URI
- installer: ClaudeTaskSetup.ico wired as ApplicationIcon and embedded
  as a WPF Resource so WizardWindow and SettingsWindow can reference it
  via pack URI

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

.gitea/workflows/release.yml

@@ -67,7 +67,7 @@ jobs:
             -c Release -r win-x64 --self-contained true \
             /p:Version=$VERSION -o out/worker
 
-      - name: Publish ClaudeDo.Installer (win-x64, single-file)
+      - name: Publish ClaudeDo.Installer (win-x64, single-file, framework-dependent)
         env:
           WORK:    ${{ steps.ws.outputs.dir }}
           VERSION: ${{ steps.ver.outputs.version }}
@@ -75,8 +75,11 @@ jobs:
           set -euo pipefail
           export PATH="$DOTNET_ROOT:$PATH"
           cd "$WORK/src"
+          # Framework-dependent — WPF runtime pack isn't distributed on Linux SDK;
+          # the previous self-contained bundle crashed at startup (apphost AV).
+          # Target machines need .NET 8 Desktop Runtime (x64).
           dotnet publish src/ClaudeDo.Installer/ClaudeDo.Installer.csproj \
-            -c Release -r win-x64 --self-contained true \
+            -c Release -r win-x64 --self-contained false \
             /p:Version=$VERSION /p:PublishSingleFile=true \
             -o out/installer
 

global.json

@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "8.0.418",
+    "rollForward": "latestFeature"
+  }
+}

schema/schema.sql

@@ -85,6 +85,16 @@ CREATE TABLE IF NOT EXISTS task_runs (
 
 CREATE INDEX IF NOT EXISTS idx_task_runs_task_id ON task_runs(task_id);
 
+CREATE TABLE IF NOT EXISTS subtasks (
+    id         TEXT PRIMARY KEY,
+    task_id    TEXT NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
+    title      TEXT NOT NULL,
+    completed  INTEGER NOT NULL DEFAULT 0,
+    order_num  INTEGER NOT NULL,
+    created_at TIMESTAMP NOT NULL
+);
+CREATE INDEX IF NOT EXISTS idx_subtasks_task_id ON subtasks(task_id);
+
 -- Seed: minimal tag set (ignored if already present)
 INSERT OR IGNORE INTO tags (name) VALUES ('agent');
 INSERT OR IGNORE INTO tags (name) VALUES ('manual');

src/ClaudeDo.App/ClaudeDo.App.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ApplicationManifest>app.manifest</ApplicationManifest>
+    <ApplicationIcon>Assets\ClaudeTask.ico</ApplicationIcon>
     <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
   </PropertyGroup>
 

src/ClaudeDo.App/Program.cs

@@ -22,8 +22,19 @@ sealed class Program
         var factory = services.GetRequiredService<SqliteConnectionFactory>();
         SchemaInitializer.Apply(factory);
 
-        BuildAvaloniaApp()
-            .StartWithClassicDesktopLifetime(args);
+        try
+        {
+            BuildAvaloniaApp()
+                .StartWithClassicDesktopLifetime(args);
+        }
+        finally
+        {
+            // Dispose the container so WorkerClient.DisposeAsync runs —
+            // cancels the retry loop and closes the SignalR connection cleanly
+            // instead of abandoning it.
+            try { services.DisposeAsync().AsTask().GetAwaiter().GetResult(); }
+            catch { /* best effort on shutdown */ }
+        }
     }
 
     public static AppBuilder BuildAvaloniaApp()
@@ -49,6 +60,7 @@ sealed class Program
         // Repositories
         sc.AddSingleton<ListRepository>();
         sc.AddSingleton<TaskRepository>();
+        sc.AddSingleton<SubtaskRepository>();
         sc.AddSingleton<TagRepository>();
         sc.AddSingleton<WorktreeRepository>();
 
@@ -66,7 +78,8 @@ sealed class Program
             sp.GetRequiredService<ListRepository>(),
             sp.GetRequiredService<GitService>(),
             sp.GetRequiredService<WorkerClient>(),
-            sp.GetRequiredService<TagRepository>()));
+            sp.GetRequiredService<TagRepository>(),
+            sp.GetRequiredService<SubtaskRepository>()));
         sc.AddSingleton<TaskListViewModel>(sp =>
         {
             var taskRepo = sp.GetRequiredService<TaskRepository>();

src/ClaudeDo.Data/Git/GitService.cs

@@ -104,20 +104,34 @@ public sealed class GitService
         using var proc = new Process { StartInfo = psi };
         proc.Start();
 
+        // On cancellation: kill the git process tree. Killing closes the
+        // redirected pipes, which unblocks the ReadToEndAsync calls below
+        // and lets WaitForExitAsync return so the process is reaped.
+        // Without this, cancelling mid-git leaves zombie processes.
+        await using var ctr = ct.Register(() =>
+        {
+            try { proc.Kill(entireProcessTree: true); }
+            catch { /* already exited */ }
+        });
+
         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);
+        // Drain output without ct — pipes close when the process exits
+        // (whether naturally or via Kill above), so these always complete.
+        var stdoutTask = proc.StandardOutput.ReadToEndAsync();
+        var stderrTask = proc.StandardError.ReadToEndAsync();
 
-        await proc.WaitForExitAsync(ct);
+        await proc.WaitForExitAsync(CancellationToken.None);
 
         var stdout = await stdoutTask;
         var stderr = await stderrTask;
 
+        ct.ThrowIfCancellationRequested();
+
         return (proc.ExitCode, stdout.TrimEnd(), stderr.TrimEnd());
     }
 }

src/ClaudeDo.Data/Models/SubtaskEntity.cs

@@ -0,0 +1,11 @@
+namespace ClaudeDo.Data.Models;
+
+public sealed class SubtaskEntity
+{
+    public required string Id { get; init; }
+    public required string TaskId { get; init; }
+    public required string Title { get; set; }
+    public bool Completed { get; set; }
+    public int OrderNum { get; set; }
+    public required DateTime CreatedAt { get; init; }
+}

src/ClaudeDo.Data/Repositories/SubtaskRepository.cs

@@ -0,0 +1,81 @@
+using ClaudeDo.Data.Models;
+using Microsoft.Data.Sqlite;
+
+namespace ClaudeDo.Data.Repositories;
+
+public sealed class SubtaskRepository
+{
+    private readonly SqliteConnectionFactory _factory;
+
+    public SubtaskRepository(SqliteConnectionFactory factory) => _factory = factory;
+
+    public async Task<List<SubtaskEntity>> GetByTaskIdAsync(string taskId, CancellationToken ct = default)
+    {
+        await using var conn = _factory.Open();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = "SELECT id, task_id, title, completed, order_num, created_at FROM subtasks WHERE task_id = @task_id ORDER BY order_num";
+        cmd.Parameters.AddWithValue("@task_id", taskId);
+
+        await using var reader = await cmd.ExecuteReaderAsync(ct);
+        var result = new List<SubtaskEntity>();
+        while (await reader.ReadAsync(ct))
+            result.Add(ReadSubtask(reader));
+        return result;
+    }
+
+    public async Task AddAsync(SubtaskEntity entity, CancellationToken ct = default)
+    {
+        await using var conn = _factory.Open();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = """
+            INSERT INTO subtasks (id, task_id, title, completed, order_num, created_at)
+            VALUES (@id, @task_id, @title, @completed, @order_num, @created_at)
+            """;
+        BindSubtask(cmd, entity);
+        await cmd.ExecuteNonQueryAsync(ct);
+    }
+
+    public async Task UpdateAsync(SubtaskEntity entity, CancellationToken ct = default)
+    {
+        await using var conn = _factory.Open();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = """
+            UPDATE subtasks SET title = @title, completed = @completed, order_num = @order_num
+            WHERE id = @id
+            """;
+        cmd.Parameters.AddWithValue("@id", entity.Id);
+        cmd.Parameters.AddWithValue("@title", entity.Title);
+        cmd.Parameters.AddWithValue("@completed", entity.Completed ? 1 : 0);
+        cmd.Parameters.AddWithValue("@order_num", entity.OrderNum);
+        await cmd.ExecuteNonQueryAsync(ct);
+    }
+
+    public async Task DeleteAsync(string id, CancellationToken ct = default)
+    {
+        await using var conn = _factory.Open();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = "DELETE FROM subtasks WHERE id = @id";
+        cmd.Parameters.AddWithValue("@id", id);
+        await cmd.ExecuteNonQueryAsync(ct);
+    }
+
+    private static void BindSubtask(SqliteCommand cmd, SubtaskEntity e)
+    {
+        cmd.Parameters.AddWithValue("@id", e.Id);
+        cmd.Parameters.AddWithValue("@task_id", e.TaskId);
+        cmd.Parameters.AddWithValue("@title", e.Title);
+        cmd.Parameters.AddWithValue("@completed", e.Completed ? 1 : 0);
+        cmd.Parameters.AddWithValue("@order_num", e.OrderNum);
+        cmd.Parameters.AddWithValue("@created_at", e.CreatedAt.ToString("o"));
+    }
+
+    private static SubtaskEntity ReadSubtask(SqliteDataReader r) => new()
+    {
+        Id = r.GetString(0),
+        TaskId = r.GetString(1),
+        Title = r.GetString(2),
+        Completed = r.GetInt64(3) != 0,
+        OrderNum = r.GetInt32(4),
+        CreatedAt = DateTime.Parse(r.GetString(5)),
+    };
+}

src/ClaudeDo.Data/Repositories/TaskRepository.cs

@@ -174,26 +174,36 @@ public sealed class TaskRepository
 
     public async Task<TaskEntity?> GetNextQueuedAgentTaskAsync(DateTime now, CancellationToken ct = default)
     {
+        // Atomically claim the next queued agent task: the UPDATE flips its
+        // status to 'running' in the same statement that returns its row,
+        // eliminating the TOCTOU gap where two queue-loop iterations could
+        // both select the same queued task before either marked it running.
+        // The caller is responsible for populating started_at shortly after.
         await using var conn = _factory.Open();
         await using var cmd = conn.CreateCommand();
         cmd.CommandText = """
-            SELECT t.id, t.list_id, t.title, t.description, t.status, t.scheduled_for,
-                   t.result, t.log_path, t.created_at, t.started_at, t.finished_at, t.commit_type,
-                   t.model, t.system_prompt, t.agent_path
-            FROM tasks t
-            WHERE t.status = 'queued'
-              AND (t.scheduled_for IS NULL OR t.scheduled_for <= @now)
-              AND EXISTS (
-                  SELECT 1 FROM task_tags tt
-                  JOIN tags tg ON tg.id = tt.tag_id
-                  WHERE tt.task_id = t.id AND tg.name = 'agent'
-                  UNION
-                  SELECT 1 FROM list_tags lt
-                  JOIN tags tg ON tg.id = lt.tag_id
-                  WHERE lt.list_id = t.list_id AND tg.name = 'agent'
-              )
-            ORDER BY t.created_at ASC
-            LIMIT 1
+            UPDATE tasks
+            SET status = 'running'
+            WHERE id = (
+                SELECT t.id
+                FROM tasks t
+                WHERE t.status = 'queued'
+                  AND (t.scheduled_for IS NULL OR t.scheduled_for <= @now)
+                  AND EXISTS (
+                      SELECT 1 FROM task_tags tt
+                      JOIN tags tg ON tg.id = tt.tag_id
+                      WHERE tt.task_id = t.id AND tg.name = 'agent'
+                      UNION
+                      SELECT 1 FROM list_tags lt
+                      JOIN tags tg ON tg.id = lt.tag_id
+                      WHERE lt.list_id = t.list_id AND tg.name = 'agent'
+                  )
+                ORDER BY t.created_at ASC
+                LIMIT 1
+            )
+            RETURNING id, list_id, title, description, status, scheduled_for,
+                      result, log_path, created_at, started_at, finished_at, commit_type,
+                      model, system_prompt, agent_path
             """;
         cmd.Parameters.AddWithValue("@now", now.ToString("o"));
 

src/ClaudeDo.Installer/App.xaml.cs

@@ -111,6 +111,7 @@ public partial class App : Application
         sc.AddSingleton<IInstallStep, InitDatabaseStep>();
         sc.AddSingleton<IInstallStep, RegisterServiceStep>();
         sc.AddSingleton<IInstallStep, CreateShortcutsStep>();
+        sc.AddSingleton<IInstallStep, WriteUninstallRegistryStep>();
         sc.AddSingleton<WriteInstallManifestStep>();
         sc.AddSingleton<IInstallStep>(sp => sp.GetRequiredService<WriteInstallManifestStep>());
 

src/ClaudeDo.Installer/ClaudeDo.Installer.csproj

@@ -6,8 +6,16 @@
     <UseWPF>true</UseWPF>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
+    <!-- Allow Linux Gitea runners to publish this WPF project for win-x64; no-op on Windows. -->
+    <EnableWindowsTargeting>true</EnableWindowsTargeting>
+    <ApplicationIcon>ClaudeTaskSetup.ico</ApplicationIcon>
   </PropertyGroup>
 
+  <ItemGroup>
+    <!-- Embed icon so it is available via pack URI in WPF windows. -->
+    <Resource Include="ClaudeTaskSetup.ico" />
+  </ItemGroup>
+
   <!-- Debug: asInvoker so Rider/VS can debug without elevation -->
   <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
     <ApplicationManifest>app.debug.manifest</ApplicationManifest>
@@ -19,10 +27,15 @@
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(PublishSingleFile)' == 'true'">
+    <!-- Framework-dependent: the WPF runtime pack isn't distributed for cross-compile
+         on Linux CI, which made self-contained bundles crash on startup with AV in the
+         apphost. Target machines already have the .NET 8 Desktop Runtime. -->
+    <SelfContained>false</SelfContained>
+    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == ''">win-x64</RuntimeIdentifier>
     <PublishTrimmed>false</PublishTrimmed>
     <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
     <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract>
-    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <EnableCompressionInSingleFile>false</EnableCompressionInSingleFile>
   </PropertyGroup>
 
   <ItemGroup>

src/ClaudeDo.Installer/Core/UninstallRunner.cs

@@ -1,6 +1,8 @@
+using System.Diagnostics;
 using System.IO;
 using ClaudeDo.Data;
 using ClaudeDo.Installer.Steps;
+using Microsoft.Win32;
 
 namespace ClaudeDo.Installer.Core;
 
@@ -36,6 +38,17 @@ public sealed class UninstallRunner
         progress.Report("Unregistering service...");
         await ProcessRunner.RunAsync("sc.exe", $"delete {StopServiceStep.ServiceName}", null, progress, ct);
 
+        // 3b) Remove Apps & Features registry entry (best-effort).
+        progress.Report("Removing Add/Remove Programs entry...");
+        try
+        {
+            Registry.LocalMachine.DeleteSubKeyTree(WriteUninstallRegistryStep.UninstallKeyPath, throwOnMissingSubKey: false);
+        }
+        catch (Exception ex)
+        {
+            progress.Report($"Warning: could not delete uninstall registry key: {ex.Message}");
+        }
+
         // 4) Remove shortcuts (best-effort — a stuck .lnk must not block the rest).
         progress.Report("Removing shortcuts...");
         TryDeleteFile(Path.Combine(
@@ -63,6 +76,21 @@ public sealed class UninstallRunner
                 failures.Add($"app data ({appData}): {err}");
         }
 
+        // 7) If we were launched from inside the install dir (Apps & Features case),
+        //    our own exe is still locked — schedule a cmd.exe trampoline to finish
+        //    the deletion after this process exits. Best-effort: if this fails the
+        //    user is left with an empty <uninstaller> folder which is harmless.
+        var runningExe = Environment.ProcessPath;
+        if (runningExe is not null
+            && IsInsideDirectory(runningExe, _context.InstallDirectory)
+            && Directory.Exists(_context.InstallDirectory))
+        {
+            progress.Report("Scheduling final cleanup after exit...");
+            TryScheduleTrampolineDelete(_context.InstallDirectory);
+            // The trampoline will finish the job — clear the residual failure entry for the install dir.
+            failures.RemoveAll(f => f.StartsWith("install dir"));
+        }
+
         if (failures.Count > 0)
         {
             return StepResult.Fail(
@@ -74,6 +102,37 @@ public sealed class UninstallRunner
         return StepResult.Ok();
     }
 
+    private static bool IsInsideDirectory(string filePath, string directory)
+    {
+        try
+        {
+            var full = Path.GetFullPath(filePath);
+            var dir = Path.GetFullPath(directory).TrimEnd(Path.DirectorySeparatorChar) + Path.DirectorySeparatorChar;
+            return full.StartsWith(dir, StringComparison.OrdinalIgnoreCase);
+        }
+        catch { return false; }
+    }
+
+    private static void TryScheduleTrampolineDelete(string installDir)
+    {
+        try
+        {
+            var pid = Environment.ProcessId;
+            // Wait for this process to exit, then recursively remove the install dir.
+            // /B timeout avoids a visible window; ping as a portable sleep; rmdir /S /Q is silent.
+            var cmd = $"/C start \"\" /MIN cmd /C \"ping 127.0.0.1 -n 3 >nul & rmdir /S /Q \"\"{installDir}\"\"\"";
+            Process.Start(new ProcessStartInfo
+            {
+                FileName = "cmd.exe",
+                Arguments = cmd,
+                UseShellExecute = false,
+                CreateNoWindow = true,
+                WindowStyle = ProcessWindowStyle.Hidden,
+            });
+        }
+        catch { /* best effort */ }
+    }
+
     /// <summary>
     /// Guards against catastrophic recursive-delete paths. The install dir must be
     /// a non-root directory with a non-empty name (e.g. reject "", "C:\\", "/").

src/ClaudeDo.Installer/Pages/InstallPage/InstallPageViewModel.cs

@@ -54,6 +54,7 @@ public partial class InstallPageViewModel : ObservableObject, IInstallerPage
             Steps.Add(new StepViewModel("Initialize Database"));
             Steps.Add(new StepViewModel("Register Windows Service"));
             Steps.Add(new StepViewModel("Create Shortcuts"));
+            Steps.Add(new StepViewModel("Register in Add/Remove Programs"));
             Steps.Add(new StepViewModel("Write Install Manifest"));
         }
         return Task.CompletedTask;
@@ -82,7 +83,21 @@ public partial class InstallPageViewModel : ObservableObject, IInstallerPage
 
             step.Status = p.Status;
             if (p.Message is not null)
-                step.Messages.Add(p.Message);
+            {
+                // Messages starting with "\r" overwrite the previous line (live progress).
+                if (p.Message.StartsWith('\r'))
+                {
+                    var line = p.Message[1..];
+                    if (step.Messages.Count > 0 && step.Messages[^1].StartsWith("  "))
+                        step.Messages[^1] = line;
+                    else
+                        step.Messages.Add(line);
+                }
+                else
+                {
+                    step.Messages.Add(p.Message);
+                }
+            }
 
             if (p.Status is StepStatus.Running && !step.IsExpanded)
                 step.IsExpanded = true;

src/ClaudeDo.Installer/Steps/DownloadAndExtractStep.cs

@@ -44,9 +44,18 @@ public sealed class DownloadAndExtractStep : IInstallStep
             var zipPath = Path.Combine(scratchDir, zipAsset.Name);
             var checksumPath = Path.Combine(scratchDir, "checksums.txt");
 
-            progress.Report($"Downloading {zipAsset.Name} ({zipAsset.Size / (1024 * 1024)} MB)...");
+            var totalMb = zipAsset.Size / (1024 * 1024);
+            progress.Report($"Downloading {zipAsset.Name} ({totalMb} MB)...");
+            long lastReportedMb = -1;
             await _releases.DownloadAsync(zipAsset.BrowserDownloadUrl, zipPath,
-                new Progress<long>(b => progress.Report($"  {b / (1024 * 1024)} MB downloaded")),
+                new Progress<long>(b =>
+                {
+                    var mb = b / (1024 * 1024);
+                    if (mb == lastReportedMb) return;
+                    lastReportedMb = mb;
+                    // Leading "\r" tells the UI to overwrite the previous line instead of appending.
+                    progress.Report($"\r  {mb} / {totalMb} MB downloaded");
+                }),
                 ct);
 
             progress.Report("Downloading checksums...");

src/ClaudeDo.Installer/Steps/RegisterServiceStep.cs

@@ -23,6 +23,24 @@ public sealed class RegisterServiceStep : IInstallStep
         progress.Report("Removing existing service registration (if any)...");
         await RunSc($"delete {ServiceName}", ctx, progress, ct, ignoreErrors: true);
 
+        // Wait for the service to actually disappear from SCM. `sc delete` returns
+        // immediately but the service stays "marked for deletion" until every open
+        // handle (services.msc, Task Manager, a prior sc query process) is closed.
+        // Poll up to 30s — then fail with actionable guidance if it's still there.
+        progress.Report("Waiting for prior service registration to clear...");
+        for (var i = 0; i < 30; i++)
+        {
+            ct.ThrowIfCancellationRequested();
+            var (queryExit, _) = await RunSc($"query {ServiceName}", ctx, progress, ct, ignoreErrors: true);
+            if (queryExit != 0) break; // service no longer registered — good
+            if (i == 29)
+                return StepResult.Fail(
+                    $"Service '{ServiceName}' is marked for deletion but hasn't cleared after 30s. " +
+                    "Close any open Services console (services.msc), Task Manager Services tab, or " +
+                    "Event Viewer showing the service, then retry. A reboot will also clear it.");
+            await Task.Delay(1000, ct);
+        }
+
         // Create service
         var startType = ctx.AutoStart ? "auto" : "demand";
         var createArgs = $"create {ServiceName} binPath= \"{workerExe}\" start= {startType}";
@@ -35,6 +53,10 @@ public sealed class RegisterServiceStep : IInstallStep
 
         progress.Report("Creating service...");
         var (exitCode, output) = await RunSc(createArgs, ctx, progress, ct);
+        if (exitCode == 1072)
+            return StepResult.Fail(
+                $"Service '{ServiceName}' is still marked for deletion. " +
+                "Close services.msc / Task Manager / Event Viewer and retry, or reboot.");
         if (exitCode != 0)
             return StepResult.Fail($"sc.exe create failed (exit {exitCode}): {output}");
 

src/ClaudeDo.Installer/Steps/StopServiceStep.cs

@@ -27,6 +27,12 @@ public sealed class StopServiceStep : IInstallStep
         }
 
         var (stopExit, _) = await ProcessRunner.RunAsync("sc.exe", $"stop {ServiceName}", null, progress, ct);
+        // 1062 = ERROR_SERVICE_NOT_ACTIVE — registered but not running, treat as already stopped.
+        if (stopExit == 1062)
+        {
+            progress.Report("Service was registered but not running.");
+            return StepResult.Ok();
+        }
         if (stopExit != 0)
             return StepResult.Fail($"sc.exe stop failed with exit code {stopExit}");
 

src/ClaudeDo.Installer/Steps/WriteUninstallRegistryStep.cs

@@ -0,0 +1,81 @@
+using System.IO;
+using ClaudeDo.Installer.Core;
+using Microsoft.Win32;
+
+namespace ClaudeDo.Installer.Steps;
+
+/// <summary>
+/// Registers ClaudeDo under <c>HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ClaudeDo</c>
+/// so it shows up in Windows "Apps &amp; Features" / "Programs and Features".
+/// Also copies the running installer into the install directory so there is an exe
+/// for UninstallString to reference after the temp-extracted single-file bundle is gone.
+/// </summary>
+public sealed class WriteUninstallRegistryStep : IInstallStep
+{
+    internal const string UninstallKeyPath = @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ClaudeDo";
+
+    public string Name => "Register in Add/Remove Programs";
+
+    public async Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
+    {
+        var uninstallDir = Path.Combine(ctx.InstallDirectory, "uninstaller");
+        Directory.CreateDirectory(uninstallDir);
+        var targetExe = Path.Combine(uninstallDir, "ClaudeDo.Installer.exe");
+
+        // Copy the running installer so Apps & Features has a stable exe to launch —
+        // the single-file temp extract is gone once this process exits.
+        var sourceExe = Environment.ProcessPath
+            ?? throw new InvalidOperationException("Cannot resolve running installer path.");
+        try
+        {
+            progress.Report("Copying uninstaller binary...");
+            File.Copy(sourceExe, targetExe, overwrite: true);
+        }
+        catch (Exception ex)
+        {
+            return StepResult.Fail($"Failed to copy uninstaller exe: {ex.Message}");
+        }
+
+        progress.Report("Writing Add/Remove Programs entry...");
+        try
+        {
+            using var key = Registry.LocalMachine.CreateSubKey(UninstallKeyPath, writable: true);
+            if (key is null)
+                return StepResult.Fail("Could not open uninstall registry key (permission denied?).");
+
+            key.SetValue("DisplayName", "ClaudeDo", RegistryValueKind.String);
+            key.SetValue("DisplayVersion", ctx.InstallerVersion ?? "0.0.0", RegistryValueKind.String);
+            key.SetValue("Publisher", "Mika Kuns", RegistryValueKind.String);
+            key.SetValue("InstallLocation", ctx.InstallDirectory, RegistryValueKind.String);
+            key.SetValue("UninstallString", $"\"{targetExe}\"", RegistryValueKind.String);
+            key.SetValue("DisplayIcon", targetExe, RegistryValueKind.String);
+            key.SetValue("NoModify", 1, RegistryValueKind.DWord);
+            key.SetValue("NoRepair", 1, RegistryValueKind.DWord);
+
+            // Best-effort install size (KB) — scan install dir.
+            try
+            {
+                var sizeKb = (int)(DirectorySizeBytes(ctx.InstallDirectory) / 1024);
+                key.SetValue("EstimatedSize", sizeKb, RegistryValueKind.DWord);
+            }
+            catch { /* best-effort only */ }
+        }
+        catch (Exception ex)
+        {
+            return StepResult.Fail($"Failed to write uninstall registry: {ex.Message}");
+        }
+
+        await Task.CompletedTask;
+        return StepResult.Ok();
+    }
+
+    private static long DirectorySizeBytes(string path)
+    {
+        long total = 0;
+        foreach (var file in Directory.EnumerateFiles(path, "*", SearchOption.AllDirectories))
+        {
+            try { total += new FileInfo(file).Length; } catch { /* ignore */ }
+        }
+        return total;
+    }
+}

src/ClaudeDo.Installer/Theme/DarkTheme.xaml

@@ -184,6 +184,34 @@
         </Setter>
     </Style>
 
+    <!-- ComboBox toggle button (dropdown arrow chrome) -->
+    <ControlTemplate x:Key="ComboBoxToggleButtonTemplate" TargetType="ToggleButton">
+        <Border x:Name="Bd"
+                Background="{StaticResource IslandBgBrush}"
+                BorderBrush="{StaticResource BorderSubtleBrush}"
+                BorderThickness="1"
+                CornerRadius="4">
+            <Grid>
+                <Grid.ColumnDefinitions>
+                    <ColumnDefinition Width="*"/>
+                    <ColumnDefinition Width="20"/>
+                </Grid.ColumnDefinitions>
+                <Path Grid.Column="1"
+                      HorizontalAlignment="Center" VerticalAlignment="Center"
+                      Fill="{StaticResource TextSecondaryBrush}"
+                      Data="M 0 0 L 4 4 L 8 0 Z"/>
+            </Grid>
+        </Border>
+        <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+                <Setter TargetName="Bd" Property="BorderBrush" Value="{StaticResource AccentBrush}"/>
+            </Trigger>
+            <Trigger Property="IsChecked" Value="True">
+                <Setter TargetName="Bd" Property="BorderBrush" Value="{StaticResource AccentBrush}"/>
+            </Trigger>
+        </ControlTemplate.Triggers>
+    </ControlTemplate>
+
     <!-- ComboBox -->
     <Style TargetType="ComboBox">
         <Setter Property="Background" Value="{StaticResource IslandBgBrush}"/>
@@ -191,6 +219,71 @@
         <Setter Property="BorderBrush" Value="{StaticResource BorderSubtleBrush}"/>
         <Setter Property="BorderThickness" Value="1"/>
         <Setter Property="Padding" Value="8,6"/>
+        <Setter Property="SnapsToDevicePixels" Value="True"/>
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ComboBox">
+                    <Grid>
+                        <ToggleButton x:Name="ToggleButton"
+                                      Template="{StaticResource ComboBoxToggleButtonTemplate}"
+                                      Focusable="False"
+                                      IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
+                                      ClickMode="Press"/>
+                        <ContentPresenter x:Name="ContentSite"
+                                          IsHitTestVisible="False"
+                                          Content="{TemplateBinding SelectionBoxItem}"
+                                          ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
+                                          ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
+                                          Margin="{TemplateBinding Padding}"
+                                          VerticalAlignment="Center" HorizontalAlignment="Left"
+                                          TextElement.Foreground="{StaticResource TextPrimaryBrush}"/>
+                        <Popup x:Name="Popup"
+                               Placement="Bottom"
+                               IsOpen="{TemplateBinding IsDropDownOpen}"
+                               AllowsTransparency="True" Focusable="False"
+                               PopupAnimation="Slide">
+                            <Border x:Name="DropDownBorder"
+                                    Background="{StaticResource IslandBgBrush}"
+                                    BorderBrush="{StaticResource BorderSubtleBrush}"
+                                    BorderThickness="1"
+                                    CornerRadius="4"
+                                    MinWidth="{TemplateBinding ActualWidth}"
+                                    MaxHeight="{TemplateBinding MaxDropDownHeight}">
+                                <ScrollViewer SnapsToDevicePixels="True">
+                                    <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained"/>
+                                </ScrollViewer>
+                            </Border>
+                        </Popup>
+                    </Grid>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!-- ComboBoxItem — dark dropdown rows -->
+    <Style TargetType="ComboBoxItem">
+        <Setter Property="Background" Value="{StaticResource IslandBgBrush}"/>
+        <Setter Property="Foreground" Value="{StaticResource TextPrimaryBrush}"/>
+        <Setter Property="Padding" Value="8,6"/>
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ComboBoxItem">
+                    <Border x:Name="Bd"
+                            Background="{TemplateBinding Background}"
+                            Padding="{TemplateBinding Padding}">
+                        <ContentPresenter/>
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsHighlighted" Value="True">
+                            <Setter TargetName="Bd" Property="Background" Value="{StaticResource SelectionHoverBrush}"/>
+                        </Trigger>
+                        <Trigger Property="IsSelected" Value="True">
+                            <Setter TargetName="Bd" Property="Background" Value="{StaticResource SelectionBrush}"/>
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
     </Style>
 
     <!-- CheckBox -->

src/ClaudeDo.Installer/Views/SettingsWindow.xaml

@@ -3,9 +3,14 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:views="clr-namespace:ClaudeDo.Installer.Views"
         Title="ClaudeDo Settings"
+        Icon="/ClaudeTaskSetup.ico"
         Width="720" Height="520"
         MinWidth="620" MinHeight="460"
         WindowStartupLocation="CenterScreen"
+        Background="{StaticResource WindowBgBrush}"
+        Foreground="{StaticResource TextPrimaryBrush}"
+        FontFamily="Segoe UI"
+        FontSize="13"
         d:DataContext="{d:DesignInstance views:SettingsViewModel}"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

src/ClaudeDo.Installer/Views/WizardWindow.xaml

@@ -3,9 +3,14 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:views="clr-namespace:ClaudeDo.Installer.Views"
         Title="ClaudeDo Installer"
+        Icon="/ClaudeTaskSetup.ico"
         Width="720" Height="520"
         MinWidth="620" MinHeight="460"
         WindowStartupLocation="CenterScreen"
+        Background="{StaticResource WindowBgBrush}"
+        Foreground="{StaticResource TextPrimaryBrush}"
+        FontFamily="Segoe UI"
+        FontSize="13"
         d:DataContext="{d:DesignInstance views:WizardViewModel}"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

src/ClaudeDo.Ui/ViewModels/SubtaskItemViewModel.cs

@@ -0,0 +1,23 @@
+using ClaudeDo.Data.Models;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace ClaudeDo.Ui.ViewModels;
+
+public partial class SubtaskItemViewModel : ObservableObject
+{
+    [ObservableProperty] private string _title = string.Empty;
+    [ObservableProperty] private bool _completed;
+
+    public string Id { get; set; } = string.Empty;
+    public string? OriginalTitle { get; set; }
+    public bool OriginalCompleted { get; set; }
+
+    public static SubtaskItemViewModel From(SubtaskEntity e) => new()
+    {
+        Id = e.Id,
+        Title = e.Title,
+        Completed = e.Completed,
+        OriginalTitle = e.Title,
+        OriginalCompleted = e.Completed,
+    };
+}

src/ClaudeDo.Ui/ViewModels/TaskDetailViewModel.cs

@@ -20,6 +20,7 @@ public partial class TaskDetailViewModel : ViewModelBase
     private readonly GitService _git;
     private readonly WorkerClient _worker;
     private readonly TagRepository _tagRepo;
+    private readonly SubtaskRepository _subtaskRepo;
 
     [ObservableProperty] private string _title = "";
     [ObservableProperty] private string? _description;
@@ -28,9 +29,14 @@ public partial class TaskDetailViewModel : ViewModelBase
     [ObservableProperty] private string _statusText = "";
     [ObservableProperty] private string _statusChoice = "Manual";
     [ObservableProperty] private string _commitType = "chore";
+    [ObservableProperty] private string _modelChoice = "(list default)";
+    [ObservableProperty] private string? _systemPromptOverride;
+    [ObservableProperty] private AgentInfo? _selectedAgent;
+    public List<AgentInfo> AvailableAgents { get; } = [];
 
     public static string[] StatusChoices { get; } = ["Manual", "Queued", "Running", "Done", "Failed"];
     public static string[] CommitTypes { get; } = ["feat", "fix", "refactor", "docs", "test", "chore", "ci", "perf", "style", "build"];
+    public static string[] ModelChoices { get; } = ["(list default)", "Sonnet", "Opus", "Haiku"];
 
     // Worktree
     [ObservableProperty] private bool _hasWorktree;
@@ -44,15 +50,21 @@ public partial class TaskDetailViewModel : ViewModelBase
     private StreamLineFormatter _formatter = new();
     public ObservableCollection<TagEntity> Tags { get; } = new();
     [ObservableProperty] private string _newTagInput = "";
+    public ObservableCollection<SubtaskItemViewModel> Subtasks { get; } = new();
 
     private string? _taskId;
     private string? _listId;
     private bool _isLoading;
+    // Cancels an in-flight LoadAsync when a new TaskUpdated event arrives
+    // before the previous load finished — prevents torn state on _taskId,
+    // Subtasks, Tags, etc.
+    private CancellationTokenSource? _loadCts;
 
     public event Action<string>? TaskChanged;
 
     public TaskDetailViewModel(TaskRepository taskRepo, WorktreeRepository worktreeRepo,
-        ListRepository listRepo, GitService git, WorkerClient worker, TagRepository tagRepo)
+        ListRepository listRepo, GitService git, WorkerClient worker, TagRepository tagRepo,
+        SubtaskRepository subtaskRepo)
     {
         _taskRepo = taskRepo;
         _worktreeRepo = worktreeRepo;
@@ -60,6 +72,7 @@ public partial class TaskDetailViewModel : ViewModelBase
         _git = git;
         _worker = worker;
         _tagRepo = tagRepo;
+        _subtaskRepo = subtaskRepo;
 
         worker.TaskMessageEvent += OnTaskMessage;
         worker.WorktreeUpdatedEvent += OnWorktreeUpdated;
@@ -70,43 +83,98 @@ public partial class TaskDetailViewModel : ViewModelBase
 
     public async Task LoadAsync(string taskId)
     {
+        // Cancel any in-flight load so rapid TaskUpdated events don't race
+        // on _taskId / Subtasks / Tags. The newest caller wins.
+        var oldCts = _loadCts;
+        var cts = new CancellationTokenSource();
+        _loadCts = cts;
+        oldCts?.Cancel();
+        oldCts?.Dispose();
+        var ct = cts.Token;
+
         _taskId = taskId;
         LiveText = "";
         _formatter = new StreamLineFormatter();
 
-        var task = await _taskRepo.GetByIdAsync(taskId);
-        if (task is null) return;
-
-        _isLoading = true;
         try
         {
-            _listId = task.ListId;
-            Title = task.Title;
-            Description = task.Description;
-            Result = task.Result;
-            LogPath = task.LogPath;
-            if (task.LogPath is not null
-                && task.Status is Data.Models.TaskStatus.Done or Data.Models.TaskStatus.Failed
-                && File.Exists(task.LogPath))
+            var task = await _taskRepo.GetByIdAsync(taskId, ct);
+            if (task is null) return;
+            ct.ThrowIfCancellationRequested();
+
+            if (AvailableAgents.Count == 0)
             {
-                _formatter = new StreamLineFormatter();
-                LiveText = await Task.Run(() => _formatter.FormatFile(task.LogPath));
+                var agents = await _worker.GetAgentsAsync();
+                ct.ThrowIfCancellationRequested();
+                AvailableAgents.AddRange(agents);
+                OnPropertyChanged(nameof(AvailableAgents));
             }
-            StatusText = task.Status.ToString().ToLowerInvariant();
-            StatusChoice = task.Status.ToString();
-            CommitType = task.CommitType;
 
-            Tags.Clear();
-            var tags = await _taskRepo.GetTagsAsync(taskId);
-            foreach (var tag in tags)
-                Tags.Add(tag);
+            _isLoading = true;
+            try
+            {
+                _listId = task.ListId;
+                Title = task.Title;
+                Description = task.Description;
+                Result = task.Result;
+                LogPath = task.LogPath;
+                if (task.LogPath is not null
+                    && task.Status is Data.Models.TaskStatus.Done or Data.Models.TaskStatus.Failed
+                    && File.Exists(task.LogPath))
+                {
+                    _formatter = new StreamLineFormatter();
+                    LiveText = await Task.Run(() => _formatter.FormatFile(task.LogPath), ct);
+                }
+                StatusText = task.Status.ToString().ToLowerInvariant();
+                StatusChoice = task.Status.ToString();
+                CommitType = task.CommitType;
+                ModelChoice = task.Model is not null
+                    ? ListEditorViewModel.ModelIdToDisplay(task.Model)
+                    : "(list default)";
+                SystemPromptOverride = task.SystemPrompt;
+                if (task.AgentPath is not null)
+                {
+                    var match = AvailableAgents.FirstOrDefault(a => a.Path == task.AgentPath);
+                    if (match is null)
+                    {
+                        match = new AgentInfo(Path.GetFileNameWithoutExtension(task.AgentPath), "(external)", task.AgentPath);
+                        AvailableAgents.Add(match);
+                        OnPropertyChanged(nameof(AvailableAgents));
+                    }
+                    SelectedAgent = match;
+                }
+                else
+                {
+                    SelectedAgent = null;
+                }
+
+                Tags.Clear();
+                var tags = await _taskRepo.GetTagsAsync(taskId, ct);
+                foreach (var tag in tags)
+                    Tags.Add(tag);
+
+                // Tear down old subtask subscriptions before replacing them.
+                foreach (var old in Subtasks) old.PropertyChanged -= OnSubtaskPropertyChanged;
+                Subtasks.Clear();
+                var subtasks = await _subtaskRepo.GetByTaskIdAsync(taskId, ct);
+                foreach (var s in subtasks)
+                {
+                    var vm = SubtaskItemViewModel.From(s);
+                    vm.PropertyChanged += OnSubtaskPropertyChanged;
+                    Subtasks.Add(vm);
+                }
+            }
+            finally
+            {
+                _isLoading = false;
+            }
+
+            await LoadWorktreeAsync(taskId);
         }
-        finally
+        catch (OperationCanceledException)
         {
-            _isLoading = false;
+            // Superseded by a newer LoadAsync — nothing to do.
         }
-
-        await LoadWorktreeAsync(taskId);
     }
 
     public async Task SaveAsync()
@@ -119,6 +187,11 @@ public partial class TaskDetailViewModel : ViewModelBase
         entity.Title = Title;
         entity.Description = Description;
         entity.CommitType = CommitType;
+        entity.Model = ModelChoice != "(list default)"
+            ? ListEditorViewModel.ModelDisplayToId(ModelChoice)
+            : null;
+        entity.SystemPrompt = string.IsNullOrWhiteSpace(SystemPromptOverride) ? null : SystemPromptOverride.Trim();
+        entity.AgentPath = SelectedAgent?.Path;
 
         if (Enum.TryParse<Data.Models.TaskStatus>(StatusChoice, true, out var status))
             entity.Status = status;
@@ -155,8 +228,76 @@ public partial class TaskDetailViewModel : ViewModelBase
         TaskChanged?.Invoke(_taskId);
     }
 
+    [RelayCommand]
+    private async Task AddSubtask()
+    {
+        if (_taskId is null) return;
+        var entity = new SubtaskEntity
+        {
+            Id = Guid.NewGuid().ToString(),
+            TaskId = _taskId,
+            Title = "",
+            Completed = false,
+            OrderNum = Subtasks.Count,
+            CreatedAt = DateTime.UtcNow,
+        };
+        await _subtaskRepo.AddAsync(entity);
+        var vm = SubtaskItemViewModel.From(entity);
+        vm.PropertyChanged += OnSubtaskPropertyChanged;
+        Subtasks.Add(vm);
+    }
+
+    [RelayCommand]
+    private async Task RemoveSubtask(SubtaskItemViewModel item)
+    {
+        if (!string.IsNullOrEmpty(item.Id))
+            await _subtaskRepo.DeleteAsync(item.Id);
+        item.PropertyChanged -= OnSubtaskPropertyChanged;
+        Subtasks.Remove(item);
+    }
+
+    private async void OnSubtaskPropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+    {
+        if (_isLoading || sender is not SubtaskItemViewModel vm || string.IsNullOrEmpty(vm.Id)) return;
+        if (e.PropertyName is not (nameof(SubtaskItemViewModel.Title) or nameof(SubtaskItemViewModel.Completed))) return;
+        try
+        {
+            await _subtaskRepo.UpdateAsync(new SubtaskEntity
+            {
+                Id = vm.Id,
+                TaskId = _taskId ?? "",
+                Title = vm.Title,
+                Completed = vm.Completed,
+                OrderNum = Subtasks.IndexOf(vm),
+                CreatedAt = DateTime.UtcNow,
+            });
+        }
+        catch (Exception ex)
+        {
+            // async void must never throw — surface via Debug.
+            Debug.WriteLine($"[TaskDetailViewModel] Subtask update failed for {vm.Id}: {ex}");
+        }
+    }
+
+    public void SetAgentFromPath(string path)
+    {
+        var existing = AvailableAgents.FirstOrDefault(a => a.Path == path);
+        if (existing is null)
+        {
+            existing = new AgentInfo(Path.GetFileNameWithoutExtension(path), "(external)", path);
+            AvailableAgents.Add(existing);
+            OnPropertyChanged(nameof(AvailableAgents));
+        }
+        SelectedAgent = existing;
+    }
+
     public void Clear()
     {
+        // Cancel any load in flight so it doesn't resurrect state after Clear.
+        _loadCts?.Cancel();
+        _loadCts?.Dispose();
+        _loadCts = null;
+
         _taskId = null;
         _listId = null;
         Title = "";
@@ -169,8 +310,13 @@ public partial class TaskDetailViewModel : ViewModelBase
         _formatter = new StreamLineFormatter();
         Tags.Clear();
         NewTagInput = "";
+        foreach (var s in Subtasks) s.PropertyChanged -= OnSubtaskPropertyChanged;
+        Subtasks.Clear();
         StatusChoice = "Manual";
         CommitType = "chore";
+        ModelChoice = "(list default)";
+        SystemPromptOverride = null;
+        SelectedAgent = null;
     }
 
     private async Task LoadWorktreeAsync(string taskId)
@@ -299,12 +445,28 @@ public partial class TaskDetailViewModel : ViewModelBase
     private async void OnWorktreeUpdated(string taskId)
     {
         if (taskId != _taskId) return;
-        await LoadWorktreeAsync(taskId);
+        try
+        {
+            await LoadWorktreeAsync(taskId);
+        }
+        catch (Exception ex)
+        {
+            // async void must never throw.
+            Debug.WriteLine($"[TaskDetailViewModel] OnWorktreeUpdated failed for {taskId}: {ex}");
+        }
     }
 
     private async void OnTaskUpdated(string taskId)
     {
         if (taskId != _taskId) return;
-        await LoadAsync(taskId);
+        try
+        {
+            await LoadAsync(taskId);
+        }
+        catch (Exception ex)
+        {
+            // async void must never throw.
+            Debug.WriteLine($"[TaskDetailViewModel] OnTaskUpdated failed for {taskId}: {ex}");
+        }
     }
 }

src/ClaudeDo.Ui/ViewModels/TaskEditorViewModel.cs

@@ -1,4 +1,7 @@
+using System.Collections.ObjectModel;
+using System.IO;
 using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
 using ClaudeDo.Ui.Services;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
@@ -8,6 +11,8 @@ namespace ClaudeDo.Ui.ViewModels;
 
 public partial class TaskEditorViewModel : ViewModelBase
 {
+    private readonly SubtaskRepository _subtaskRepo;
+
     [ObservableProperty] private string _title = "";
     [ObservableProperty] private string? _description;
     [ObservableProperty] private string _commitType = "chore";
@@ -18,6 +23,7 @@ public partial class TaskEditorViewModel : ViewModelBase
     [ObservableProperty] private string? _systemPromptOverride;
     [ObservableProperty] private AgentInfo? _selectedAgent;
     public List<AgentInfo> AvailableAgents { get; set; } = [];
+    public ObservableCollection<SubtaskItemViewModel> Subtasks { get; } = new();
 
     private string? _editId;
     private string _listId = "";
@@ -34,11 +40,28 @@ public partial class TaskEditorViewModel : ViewModelBase
     public static string[] StatusChoices { get; } =
         ["manual", "queued"];
 
+    public TaskEditorViewModel(SubtaskRepository subtaskRepo)
+    {
+        _subtaskRepo = subtaskRepo;
+    }
+
     public async Task LoadAgentsAsync(WorkerClient worker)
     {
         AvailableAgents = await worker.GetAgentsAsync();
     }
 
+    public void SetAgentFromPath(string path)
+    {
+        var existing = AvailableAgents.FirstOrDefault(a => a.Path == path);
+        if (existing is null)
+        {
+            existing = new AgentInfo(Path.GetFileNameWithoutExtension(path), "(external)", path);
+            AvailableAgents.Add(existing);
+            OnPropertyChanged(nameof(AvailableAgents));
+        }
+        SelectedAgent = existing;
+    }
+
     public IReadOnlyList<string> SelectedTagNames =>
         TagsInput.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
             .Distinct()
@@ -51,8 +74,54 @@ public partial class TaskEditorViewModel : ViewModelBase
         _createdAt = DateTime.UtcNow;
         CommitType = defaultCommitType;
         WindowTitle = "New Task";
+        Subtasks.Clear();
     }
 
+    public async Task InitForEditAsync(TaskEntity entity, IReadOnlyList<TagEntity> taskTags, CancellationToken ct = default)
+    {
+        _editId = entity.Id;
+        _listId = entity.ListId;
+        _createdAt = entity.CreatedAt;
+        Title = entity.Title;
+        Description = entity.Description;
+        CommitType = entity.CommitType;
+        StatusChoice = entity.Status switch
+        {
+            TaskStatus.Manual => "manual",
+            TaskStatus.Queued => "queued",
+            _ => entity.Status.ToString().ToLowerInvariant(),
+        };
+        TagsInput = string.Join(", ", taskTags.Select(t => t.Name));
+        ModelChoice = entity.Model is not null
+            ? ListEditorViewModel.ModelIdToDisplay(entity.Model)
+            : "(list default)";
+        SystemPromptOverride = entity.SystemPrompt;
+
+        if (entity.AgentPath is not null)
+        {
+            var match = AvailableAgents.FirstOrDefault(a => a.Path == entity.AgentPath);
+            if (match is null)
+            {
+                match = new AgentInfo(Path.GetFileNameWithoutExtension(entity.AgentPath), "(external)", entity.AgentPath);
+                AvailableAgents.Add(match);
+                OnPropertyChanged(nameof(AvailableAgents));
+            }
+            SelectedAgent = match;
+        }
+        else
+        {
+            SelectedAgent = null;
+        }
+
+        WindowTitle = $"Edit Task: {entity.Title}";
+
+        Subtasks.Clear();
+        var list = await _subtaskRepo.GetByTaskIdAsync(entity.Id, ct);
+        foreach (var s in list)
+            Subtasks.Add(SubtaskItemViewModel.From(s));
+    }
+
+    // Keep old sync overload for callers that haven't loaded agents yet
     public void InitForEdit(TaskEntity entity, IReadOnlyList<TagEntity> taskTags)
     {
         _editId = entity.Id;
@@ -72,14 +141,34 @@ public partial class TaskEditorViewModel : ViewModelBase
             ? ListEditorViewModel.ModelIdToDisplay(entity.Model)
             : "(list default)";
         SystemPromptOverride = entity.SystemPrompt;
-        SelectedAgent = entity.AgentPath is not null
-            ? AvailableAgents.FirstOrDefault(a => a.Path == entity.AgentPath)
-            : null;
+
+        if (entity.AgentPath is not null)
+        {
+            var match = AvailableAgents.FirstOrDefault(a => a.Path == entity.AgentPath);
+            if (match is null)
+            {
+                match = new AgentInfo(Path.GetFileNameWithoutExtension(entity.AgentPath), "(external)", entity.AgentPath);
+                AvailableAgents.Add(match);
+                OnPropertyChanged(nameof(AvailableAgents));
+            }
+            SelectedAgent = match;
+        }
+        else
+        {
+            SelectedAgent = null;
+        }
+
         WindowTitle = $"Edit Task: {entity.Title}";
     }
 
     [RelayCommand]
-    private void Save()
+    private void AddSubtask() => Subtasks.Add(new SubtaskItemViewModel());
+
+    [RelayCommand]
+    private void RemoveSubtask(SubtaskItemViewModel item) => Subtasks.Remove(item);
+
+    [RelayCommand]
+    private async Task Save()
     {
         if (string.IsNullOrWhiteSpace(Title)) return;
         var status = StatusChoice switch
@@ -87,9 +176,10 @@ public partial class TaskEditorViewModel : ViewModelBase
             "queued" => TaskStatus.Queued,
             _ => TaskStatus.Manual,
         };
+        var taskId = _editId ?? Guid.NewGuid().ToString();
         var entity = new TaskEntity
         {
-            Id = _editId ?? Guid.NewGuid().ToString(),
+            Id = taskId,
             ListId = _listId,
             Title = Title.Trim(),
             Description = string.IsNullOrWhiteSpace(Description) ? null : Description.Trim(),
@@ -102,6 +192,42 @@ public partial class TaskEditorViewModel : ViewModelBase
             : null;
         entity.SystemPrompt = string.IsNullOrWhiteSpace(SystemPromptOverride) ? null : SystemPromptOverride.Trim();
         entity.AgentPath = SelectedAgent?.Path;
+
+        // Persist subtask changes
+        if (_editId is not null)
+        {
+            var existing = await _subtaskRepo.GetByTaskIdAsync(taskId);
+            var existingIds = existing.Select(s => s.Id).ToHashSet();
+            var currentIds = Subtasks.Where(s => s.Id != "").Select(s => s.Id).ToHashSet();
+
+            // Deleted
+            foreach (var id in existingIds.Except(currentIds))
+                await _subtaskRepo.DeleteAsync(id);
+
+            // Updated
+            foreach (var (vm, idx) in Subtasks.Select((v, i) => (v, i)))
+            {
+                if (vm.Id == "") continue;
+                if (vm.Title != vm.OriginalTitle || vm.Completed != vm.OriginalCompleted)
+                    await _subtaskRepo.UpdateAsync(new SubtaskEntity { Id = vm.Id, TaskId = taskId, Title = vm.Title, Completed = vm.Completed, OrderNum = idx, CreatedAt = DateTime.UtcNow });
+                else
+                {
+                    // update order_num if position changed
+                    var orig = existing.FirstOrDefault(e => e.Id == vm.Id);
+                    if (orig is not null && orig.OrderNum != idx)
+                        await _subtaskRepo.UpdateAsync(new SubtaskEntity { Id = vm.Id, TaskId = taskId, Title = vm.Title, Completed = vm.Completed, OrderNum = idx, CreatedAt = orig.CreatedAt });
+                }
+            }
+        }
+
+        // Added (id == "" means new)
+        foreach (var (vm, idx) in Subtasks.Select((v, i) => (v, i)).Where(x => x.v.Id == ""))
+        {
+            if (string.IsNullOrWhiteSpace(vm.Title)) continue;
+            var newId = Guid.NewGuid().ToString();
+            await _subtaskRepo.AddAsync(new SubtaskEntity { Id = newId, TaskId = taskId, Title = vm.Title.Trim(), Completed = vm.Completed, OrderNum = idx, CreatedAt = DateTime.UtcNow });
+        }
+
         _tcs.TrySetResult(entity);
         RequestClose?.Invoke();
     }

src/ClaudeDo.Ui/ViewModels/TaskListViewModel.cs

@@ -194,7 +194,7 @@ public partial class TaskListViewModel : ViewModelBase
         var taskTags = await _taskRepo.GetTagsAsync(entity.Id);
         var editor = _editorFactory();
         await editor.LoadAgentsAsync(_worker);
-        editor.InitForEdit(entity, taskTags);
+        await editor.InitForEditAsync(entity, taskTags);
 
         var window = new TaskEditorView { DataContext = editor };
         editor.RequestClose += () => window.Close();

src/ClaudeDo.Ui/Views/MainWindow.axaml

@@ -8,6 +8,7 @@
         x:Class="ClaudeDo.Ui.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
         Title="ClaudeDo"
+        Icon="avares://ClaudeDo.App/Assets/ClaudeTask.ico"
         MinWidth="800" MinHeight="500"
         KeyDown="OnGlobalKeyDown">
 
@@ -18,7 +19,7 @@
 
             <!-- Lists island -->
             <Border Grid.Column="0" CornerRadius="12" Background="{StaticResource IslandBgBrush}"
-                    MinWidth="180" MaxWidth="320" Margin="0,0,4,8" ClipToBounds="True">
+                    MinWidth="180" Margin="0,0,4,8" ClipToBounds="True">
                 <DockPanel>
                     <TextBlock DockPanel.Dock="Top"
                                Text="Lists" FontWeight="SemiBold" FontSize="13"
@@ -95,7 +96,7 @@
 
             <!-- Detail island -->
             <Border Grid.Column="2" CornerRadius="12" Background="{StaticResource IslandBgBrush}"
-                    MinWidth="280" MaxWidth="500" Margin="4,0,0,8" ClipToBounds="True">
+                    MinWidth="280" Margin="4,0,0,8" ClipToBounds="True">
                 <v:TaskDetailView DataContext="{Binding TaskDetail}" />
             </Border>
         </Grid>

src/ClaudeDo.Ui/Views/TaskDetailView.axaml

@@ -86,6 +86,71 @@
                      PlaceholderText="Add a description..."
                      LostFocus="OnFieldLostFocus"/>
 
+            <!-- Sub-Tasks -->
+            <Border Height="1" Background="{StaticResource BorderSubtleBrush}" Margin="0,8,0,4"/>
+            <TextBlock Text="Sub-Tasks" FontWeight="Bold" FontSize="13"
+                       Foreground="{StaticResource TextPrimaryBrush}"/>
+            <ItemsControl ItemsSource="{Binding Subtasks}">
+                <ItemsControl.ItemTemplate>
+                    <DataTemplate x:DataType="vm:SubtaskItemViewModel">
+                        <StackPanel Orientation="Horizontal" Spacing="6" Margin="0,2,0,2">
+                            <CheckBox IsChecked="{Binding Completed}" VerticalAlignment="Center"/>
+                            <TextBox Text="{Binding Title}" PlaceholderText="Subtask title..." Width="220"
+                                     VerticalAlignment="Center"
+                                     LostFocus="OnSubtaskTitleLostFocus"/>
+                            <Button Content="✕" Padding="6,2"
+                                    Background="Transparent" BorderThickness="0"
+                                    Foreground="{StaticResource TextMutedBrush}"
+                                    Command="{Binding $parent[UserControl].((vm:TaskDetailViewModel)DataContext).RemoveSubtaskCommand}"
+                                    CommandParameter="{Binding}"/>
+                        </StackPanel>
+                    </DataTemplate>
+                </ItemsControl.ItemTemplate>
+            </ItemsControl>
+            <Button Content="+ Add Sub-Task" Command="{Binding AddSubtaskCommand}"
+                    Background="Transparent" BorderThickness="0"
+                    Foreground="{StaticResource AccentLightBrush}" HorizontalAlignment="Left"/>
+
+            <!-- Agent Config (overrides) -->
+            <Border Height="1" Background="{StaticResource BorderSubtleBrush}" Margin="0,8,0,4"/>
+            <TextBlock Text="Agent Config (overrides)" FontWeight="Bold" FontSize="13"
+                       Foreground="{StaticResource TextPrimaryBrush}"/>
+
+            <Grid ColumnDefinitions="*,12,*" Margin="0,4,0,0">
+                <StackPanel Grid.Column="0" Spacing="4">
+                    <TextBlock Text="Model" FontSize="12" FontWeight="SemiBold"
+                               Foreground="{StaticResource TextSecondaryBrush}"/>
+                    <ComboBox ItemsSource="{Binding ModelChoices}"
+                              SelectedItem="{Binding ModelChoice}"
+                              MinWidth="100"
+                              LostFocus="OnFieldLostFocus"/>
+                </StackPanel>
+                <StackPanel Grid.Column="2" Spacing="4">
+                    <TextBlock Text="Agent File" FontSize="12" FontWeight="SemiBold"
+                               Foreground="{StaticResource TextSecondaryBrush}"/>
+                    <StackPanel Orientation="Horizontal" Spacing="4">
+                        <ComboBox ItemsSource="{Binding AvailableAgents}"
+                                  SelectedItem="{Binding SelectedAgent}"
+                                  MinWidth="100"
+                                  LostFocus="OnFieldLostFocus">
+                            <ComboBox.ItemTemplate>
+                                <DataTemplate x:DataType="m:AgentInfo">
+                                    <TextBlock Text="{Binding Name}"/>
+                                </DataTemplate>
+                            </ComboBox.ItemTemplate>
+                        </ComboBox>
+                        <Button Content="…" Click="OnBrowseAgent" ToolTip.Tip="Browse for agent .md file"/>
+                    </StackPanel>
+                </StackPanel>
+            </Grid>
+
+            <TextBlock Text="System Prompt" FontSize="12" FontWeight="SemiBold"
+                       Foreground="{StaticResource TextSecondaryBrush}" Margin="0,4,0,2"/>
+            <TextBox Text="{Binding SystemPromptOverride}"
+                     PlaceholderText="(inherits from list)"
+                     AcceptsReturn="True" TextWrapping="Wrap" MinHeight="50"
+                     LostFocus="OnFieldLostFocus"/>
+
             <!-- === READ-ONLY ZONE === -->
 
             <TextBlock Text="Result" FontWeight="SemiBold" FontSize="12"

src/ClaudeDo.Ui/Views/TaskDetailView.axaml.cs

@@ -2,6 +2,7 @@ using System.ComponentModel;
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Avalonia.Platform.Storage;
 using ClaudeDo.Ui.ViewModels;
 
 namespace ClaudeDo.Ui.Views;
@@ -19,6 +20,31 @@ public partial class TaskDetailView : UserControl
             await vm.SaveAsync();
     }
 
+    private void OnSubtaskTitleLostFocus(object? sender, RoutedEventArgs e)
+    {
+        // Title change is handled by SubtaskItemViewModel.PropertyChanged → OnSubtaskPropertyChanged in the VM
+    }
+
+    private async void OnBrowseAgent(object? sender, RoutedEventArgs e)
+    {
+        var topLevel = TopLevel.GetTopLevel(this);
+        if (topLevel is null) return;
+        var files = await topLevel.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+        {
+            Title = "Select Agent File",
+            AllowMultiple = false,
+            FileTypeFilter = new[] { new FilePickerFileType("Agent Files") { Patterns = ["*.md"] } },
+        });
+        if (files.Count == 0) return;
+        var path = files[0].TryGetLocalPath();
+        if (path is null) return;
+        if (DataContext is TaskDetailViewModel vm)
+        {
+            vm.SetAgentFromPath(path);
+            await vm.SaveAsync();
+        }
+    }
+
     private void OnTagInputKeyDown(object? sender, KeyEventArgs e)
     {
         if (e.Key == Key.Enter && DataContext is TaskDetailViewModel vm)

src/ClaudeDo.Ui/Views/TaskEditorView.axaml

@@ -35,6 +35,30 @@
         <TextBlock Text="Tags (comma-separated)" FontWeight="SemiBold" Foreground="{StaticResource TextSecondaryBrush}"/>
         <TextBox Text="{Binding TagsInput}" PlaceholderText="agent, manual, code, ..."/>
 
+        <!-- Sub-Tasks -->
+        <Border Height="1" Background="{StaticResource BorderSubtleBrush}" Margin="0,6,0,2"/>
+        <TextBlock Text="Sub-Tasks" FontWeight="Bold" FontSize="13"
+                   Foreground="{StaticResource TextPrimaryBrush}"/>
+        <ItemsControl ItemsSource="{Binding Subtasks}">
+            <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:SubtaskItemViewModel">
+                    <StackPanel Orientation="Horizontal" Spacing="6" Margin="0,2,0,2">
+                        <CheckBox IsChecked="{Binding Completed}" VerticalAlignment="Center"/>
+                        <TextBox Text="{Binding Title}" PlaceholderText="Subtask title..." Width="320"
+                                 VerticalAlignment="Center"/>
+                        <Button Content="✕" Padding="6,2"
+                                Background="Transparent" BorderThickness="0"
+                                Foreground="{StaticResource TextMutedBrush}"
+                                Command="{Binding $parent[Window].((vm:TaskEditorViewModel)DataContext).RemoveSubtaskCommand}"
+                                CommandParameter="{Binding}"/>
+                    </StackPanel>
+                </DataTemplate>
+            </ItemsControl.ItemTemplate>
+        </ItemsControl>
+        <Button Content="+ Add Sub-Task" Command="{Binding AddSubtaskCommand}"
+                Background="Transparent" BorderThickness="0"
+                Foreground="{StaticResource AccentLightBrush}" HorizontalAlignment="Left"/>
+
         <!-- Divider -->
         <Border Height="1" Background="{StaticResource BorderSubtleBrush}" Margin="0,6,0,2"/>
 
@@ -55,15 +79,18 @@
 
         <TextBlock Text="Agent File" FontWeight="SemiBold"
                    Foreground="{StaticResource TextSecondaryBrush}"/>
-        <ComboBox ItemsSource="{Binding AvailableAgents}"
-                  SelectedItem="{Binding SelectedAgent}"
-                  MinWidth="150">
-            <ComboBox.ItemTemplate>
-                <DataTemplate x:DataType="models:AgentInfo">
-                    <TextBlock Text="{Binding Name}"/>
-                </DataTemplate>
-            </ComboBox.ItemTemplate>
-        </ComboBox>
+        <StackPanel Orientation="Horizontal" Spacing="6">
+            <ComboBox ItemsSource="{Binding AvailableAgents}"
+                      SelectedItem="{Binding SelectedAgent}"
+                      MinWidth="150">
+                <ComboBox.ItemTemplate>
+                    <DataTemplate x:DataType="models:AgentInfo">
+                        <TextBlock Text="{Binding Name}"/>
+                    </DataTemplate>
+                </ComboBox.ItemTemplate>
+            </ComboBox>
+            <Button Content="…" Click="OnBrowseAgent" ToolTip.Tip="Browse for agent .md file"/>
+        </StackPanel>
 
         <StackPanel Orientation="Horizontal" Spacing="8" HorizontalAlignment="Right" Margin="0,10,0,0">
             <Button Content="Save" Command="{Binding SaveCommand}" IsDefault="True" MinWidth="80"

src/ClaudeDo.Ui/Views/TaskEditorView.axaml.cs

@@ -1,4 +1,7 @@
 using Avalonia.Controls;
+using Avalonia.Interactivity;
+using Avalonia.Platform.Storage;
+using ClaudeDo.Ui.ViewModels;
 
 namespace ClaudeDo.Ui.Views;
 
@@ -8,4 +11,19 @@ public partial class TaskEditorView : Window
     {
         InitializeComponent();
     }
+
+    private async void OnBrowseAgent(object? sender, RoutedEventArgs e)
+    {
+        var files = await StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+        {
+            Title = "Select Agent File",
+            AllowMultiple = false,
+            FileTypeFilter = new[] { new FilePickerFileType("Agent Files") { Patterns = ["*.md"] } },
+        });
+        if (files.Count == 0) return;
+        var path = files[0].TryGetLocalPath();
+        if (path is null) return;
+        if (DataContext is TaskEditorViewModel vm)
+            vm.SetAgentFromPath(path);
+    }
 }

src/ClaudeDo.Worker/ClaudeDo.Worker.csproj

@@ -6,6 +6,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.WindowsServices" Version="8.0.1" />
   </ItemGroup>
 
   <PropertyGroup>

src/ClaudeDo.Worker/Program.cs

@@ -10,6 +10,10 @@ var cfg = WorkerConfig.Load();
 
 var builder = WebApplication.CreateBuilder(args);
 
+// When launched by the Windows SCM, speak the Service Control Protocol so SCM
+// doesn't think we crashed (~30s timeout). No-op when running interactively.
+builder.Host.UseWindowsService(o => o.ServiceName = "ClaudeDoWorker");
+
 // Initialize DB schema before the host starts accepting connections.
 var dbFactory = new SqliteConnectionFactory(cfg.DbPath);
 SchemaInitializer.Apply(dbFactory);
@@ -19,6 +23,7 @@ builder.Services.AddSingleton(dbFactory);
 builder.Services.AddSingleton<TagRepository>();
 builder.Services.AddSingleton<ListRepository>();
 builder.Services.AddSingleton<TaskRepository>();
+builder.Services.AddSingleton<SubtaskRepository>();
 builder.Services.AddSingleton<WorktreeRepository>();
 builder.Services.AddSingleton<TaskRunRepository>();
 builder.Services.AddHostedService<StaleTaskRecovery>();

src/ClaudeDo.Worker/Runner/ClaudeProcess.cs

@@ -45,6 +45,9 @@ public sealed class ClaudeProcess : IClaudeProcess
         var analyzer = new StreamAnalyzer();
         var lastStderr = new StringBuilder();
 
+        // On cancellation: kill the tree. Killing closes the redirected pipes,
+        // which unblocks the ReadLineAsync loops below (which run without ct
+        // so they reliably drain instead of hanging on cancellation).
         await using var ctr = ct.Register(() =>
         {
             try { process.Kill(entireProcessTree: true); }
@@ -53,26 +56,30 @@ public sealed class ClaudeProcess : IClaudeProcess
 
         var stdoutTask = Task.Run(async () =>
         {
-            while (await process.StandardOutput.ReadLineAsync(ct) is { } line)
+            while (await process.StandardOutput.ReadLineAsync() is { } line)
             {
                 if (string.IsNullOrEmpty(line)) continue;
                 await onStdoutLine(line);
                 analyzer.ProcessLine(line);
             }
-        }, ct);
+        });
 
         var stderrTask = Task.Run(async () =>
         {
-            while (await process.StandardError.ReadLineAsync(ct) is { } line)
+            while (await process.StandardError.ReadLineAsync() is { } line)
             {
                 if (string.IsNullOrEmpty(line)) continue;
                 lastStderr.AppendLine(line);
                 await onStdoutLine($"[stderr] {line}");
             }
-        }, ct);
+        });
 
         await Task.WhenAll(stdoutTask, stderrTask);
-        await process.WaitForExitAsync(ct);
+        await process.WaitForExitAsync(CancellationToken.None);
+
+        // If we were asked to cancel, surface that to the caller now that
+        // the process is fully reaped.
+        ct.ThrowIfCancellationRequested();
 
         var exitCode = process.ExitCode;
         var streamResult = analyzer.GetResult();

src/ClaudeDo.Worker/Runner/TaskRunner.cs

@@ -12,6 +12,7 @@ public sealed class TaskRunner
     private readonly TaskRunRepository _runRepo;
     private readonly ListRepository _listRepo;
     private readonly WorktreeRepository _wtRepo;
+    private readonly SubtaskRepository _subtaskRepo;
     private readonly HubBroadcaster _broadcaster;
     private readonly WorktreeManager _wtManager;
     private readonly ClaudeArgsBuilder _argsBuilder;
@@ -24,6 +25,7 @@ public sealed class TaskRunner
         TaskRunRepository runRepo,
         ListRepository listRepo,
         WorktreeRepository wtRepo,
+        SubtaskRepository subtaskRepo,
         HubBroadcaster broadcaster,
         WorktreeManager wtManager,
         ClaudeArgsBuilder argsBuilder,
@@ -35,6 +37,7 @@ public sealed class TaskRunner
         _runRepo = runRepo;
         _listRepo = listRepo;
         _wtRepo = wtRepo;
+        _subtaskRepo = subtaskRepo;
         _broadcaster = broadcaster;
         _wtManager = wtManager;
         _argsBuilder = argsBuilder;
@@ -91,9 +94,16 @@ public sealed class TaskRunner
             await _broadcaster.TaskStarted(slot, task.Id, now);
 
             // Build prompt.
-            var prompt = string.IsNullOrWhiteSpace(task.Description)
-                ? task.Title
-                : $"{task.Title}\n\n{task.Description.Trim()}";
+            var subtasks = await _subtaskRepo.GetByTaskIdAsync(task.Id, ct);
+            var sb = new System.Text.StringBuilder(task.Title);
+            if (!string.IsNullOrWhiteSpace(task.Description)) sb.Append("\n\n").Append(task.Description.Trim());
+            if (subtasks.Count > 0)
+            {
+                sb.Append("\n\n## Sub-Tasks\n");
+                foreach (var s in subtasks)
+                    sb.Append(s.Completed ? "- [x] " : "- [ ] ").Append(s.Title).Append('\n');
+            }
+            var prompt = sb.ToString();
 
             // Run 1.
             var result = await RunOnceAsync(task.Id, slot, runDir, resolvedConfig, 1, false, prompt, ct);
@@ -222,33 +232,56 @@ public sealed class TaskRunner
 
         await using var logWriter = new LogWriter(logPath);
 
-        var result = await _claude.RunAsync(
-            arguments,
-            prompt,
-            runDir,
-            async line =>
+        try
+        {
+            var result = await _claude.RunAsync(
+                arguments,
+                prompt,
+                runDir,
+                async line =>
+                {
+                    await logWriter.WriteLineAsync(line, ct);
+                    await _broadcaster.TaskMessage(taskId, line);
+                },
+                ct);
+
+            // Update the run record with results. Use CancellationToken.None:
+            // this is a terminal write that must always complete, even if the
+            // caller's token is already cancelled.
+            run.SessionId = result.SessionId;
+            run.ResultMarkdown = result.ResultMarkdown;
+            run.StructuredOutputJson = result.StructuredOutputJson;
+            run.ErrorMarkdown = result.ErrorMarkdown;
+            run.ExitCode = result.ExitCode;
+            run.TurnCount = result.TurnCount;
+            run.TokensIn = result.TokensIn;
+            run.TokensOut = result.TokensOut;
+            run.FinishedAt = DateTime.UtcNow;
+            await _runRepo.UpdateAsync(run, CancellationToken.None);
+
+            // Update denormalized fields on the task.
+            await _taskRepo.SetLogPathAsync(taskId, logPath, CancellationToken.None);
+
+            return result;
+        }
+        catch (OperationCanceledException)
+        {
+            // Ensure the run row is completed so ContinueAsync / inspection
+            // isn't left staring at a null session_id / finished_at.
+            run.ErrorMarkdown = "Cancelled.";
+            run.ExitCode = -1;
+            run.FinishedAt = DateTime.UtcNow;
+            try
             {
-                await logWriter.WriteLineAsync(line, ct);
-                await _broadcaster.TaskMessage(taskId, line);
-            },
-            ct);
-
-        // Update the run record with results.
-        run.SessionId = result.SessionId;
-        run.ResultMarkdown = result.ResultMarkdown;
-        run.StructuredOutputJson = result.StructuredOutputJson;
-        run.ErrorMarkdown = result.ErrorMarkdown;
-        run.ExitCode = result.ExitCode;
-        run.TurnCount = result.TurnCount;
-        run.TokensIn = result.TokensIn;
-        run.TokensOut = result.TokensOut;
-        run.FinishedAt = DateTime.UtcNow;
-        await _runRepo.UpdateAsync(run, ct);
-
-        // Update denormalized fields on the task.
-        await _taskRepo.SetLogPathAsync(taskId, logPath, ct);
-
-        return result;
+                await _runRepo.UpdateAsync(run, CancellationToken.None);
+                await _taskRepo.SetLogPathAsync(taskId, logPath, CancellationToken.None);
+            }
+            catch (Exception updateEx)
+            {
+                _logger.LogError(updateEx, "Failed to finalize cancelled run {RunId} for task {TaskId}", runId, taskId);
+            }
+            throw;
+        }
     }
 
     private async Task HandleSuccess(TaskEntity task, ListEntity list, string slot, WorktreeContext? wtCtx, RunResult result, CancellationToken ct)
@@ -260,8 +293,11 @@ public sealed class TaskRunner
                 await _broadcaster.WorktreeUpdated(task.Id);
         }
 
+        // Terminal DB write uses CancellationToken.None so the task status
+        // is never left as 'running' because of a cancel that arrived
+        // after the Claude run already succeeded.
         var finishedAt = DateTime.UtcNow;
-        await _taskRepo.MarkDoneAsync(task.Id, finishedAt, result.ResultMarkdown, ct);
+        await _taskRepo.MarkDoneAsync(task.Id, finishedAt, result.ResultMarkdown, CancellationToken.None);
         await _broadcaster.TaskFinished(slot, task.Id, "done", finishedAt);
         _logger.LogInformation("Task {TaskId} completed (turns={Turns}, tokens_in={In}, tokens_out={Out})",
             task.Id, result.TurnCount, result.TokensIn, result.TokensOut);
@@ -269,8 +305,10 @@ public sealed class TaskRunner
 
     private async Task HandleFailure(string taskId, string slot, RunResult result)
     {
+        // Intentionally does not accept a CancellationToken: this is the
+        // terminal write for a failed task and must always be persisted.
         var finishedAt = DateTime.UtcNow;
-        await _taskRepo.MarkFailedAsync(taskId, finishedAt, result.ErrorMarkdown);
+        await _taskRepo.MarkFailedAsync(taskId, finishedAt, result.ErrorMarkdown, CancellationToken.None);
         await _broadcaster.TaskFinished(slot, taskId, "failed", finishedAt);
         _logger.LogWarning("Task {TaskId} failed (turns={Turns}): {Error}", taskId, result.TurnCount, result.ErrorMarkdown);
     }
@@ -280,7 +318,8 @@ public sealed class TaskRunner
         try
         {
             var now = DateTime.UtcNow;
-            await _taskRepo.MarkFailedAsync(taskId, now, error);
+            // Terminal write — never cancel.
+            await _taskRepo.MarkFailedAsync(taskId, now, error, CancellationToken.None);
             await _broadcaster.TaskFinished(slot, taskId, "failed", now);
             await _broadcaster.TaskUpdated(taskId);
         }

src/ClaudeDo.Worker/Runner/WorktreeManager.cs

@@ -31,8 +31,10 @@ public sealed class WorktreeManager
             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}";
+        // Use the full task id (dashes stripped) in the branch name so
+        // two GUIDs sharing an 8-char prefix cannot collide on the same branch.
+        var idForBranch = task.Id.Replace("-", "");
+        var branchName = $"claudedo/{idForBranch}";
         var slug = CommitMessageBuilder.ToSlug(list.Name);
 
         var worktreePath = _cfg.WorktreeRootStrategy.Equals("central", StringComparison.OrdinalIgnoreCase)

src/ClaudeDo.Worker/Services/QueueService.cs

@@ -71,6 +71,7 @@ public sealed class QueueService : BackgroundService
             _ = RunInSlotAsync(task, "override", cts.Token).ContinueWith(_ =>
             {
                 lock (_lock) { _overrideSlot = null; }
+                cts.Dispose();
             }, TaskScheduler.Default);
         }
     }
@@ -94,6 +95,7 @@ public sealed class QueueService : BackgroundService
             _ = RunContinueInSlotAsync(taskId, followUpPrompt, cts.Token).ContinueWith(_ =>
             {
                 lock (_lock) { _overrideSlot = null; }
+                cts.Dispose();
             }, TaskScheduler.Default);
         }
 
@@ -155,6 +157,7 @@ public sealed class QueueService : BackgroundService
                     _ = RunInSlotAsync(task, "queue", cts.Token).ContinueWith(_ =>
                     {
                         lock (_lock) { _queueSlot = null; }
+                        cts.Dispose();
                         WakeQueue(); // Check for next task immediately.
                     }, TaskScheduler.Default);
                 }

tests/ClaudeDo.Installer.Tests/ClaudeDo.Installer.Tests.csproj

@@ -7,6 +7,8 @@
 
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
+    <!-- Allow Linux Gitea runners to build this Windows-targeted project; no-op on Windows. -->
+    <EnableWindowsTargeting>true</EnableWindowsTargeting>
   </PropertyGroup>
 
   <ItemGroup>

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

@@ -63,7 +63,7 @@ public class WorktreeManagerTests : IDisposable
 
         Assert.NotNull(ctx);
         Assert.True(Directory.Exists(ctx.WorktreePath));
-        Assert.Equal($"claudedo/{task.Id[..8]}", ctx.BranchName);
+        Assert.Equal($"claudedo/{task.Id.Replace("-", "")}", ctx.BranchName);
         Assert.Equal(repo.BaseCommit, ctx.BaseCommit);
 
         var row = await wtRepo.GetByTaskIdAsync(task.Id);

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

@@ -51,7 +51,8 @@ public sealed class QueueServiceTests : IDisposable
         var runRepo = new TaskRunRepository(_db.Factory);
         var wtManager = new WorktreeManager(new GitService(), wtRepo, _cfg, NullLogger<WorktreeManager>.Instance);
         var argsBuilder = new ClaudeArgsBuilder();
-        var runner = new TaskRunner(fake, _taskRepo, runRepo, _listRepo, wtRepo, broadcaster, wtManager, argsBuilder, _cfg,
+        var subtaskRepo = new SubtaskRepository(_db.Factory);
+        var runner = new TaskRunner(fake, _taskRepo, runRepo, _listRepo, wtRepo, subtaskRepo, broadcaster, wtManager, argsBuilder, _cfg,
             NullLogger<TaskRunner>.Instance);
         var service = new QueueService(_taskRepo, runner, _cfg, NullLogger<QueueService>.Instance);
         return (service, fake);