diff --git a/src/ClaudeDo.Data/Git/GitService.cs b/src/ClaudeDo.Data/Git/GitService.cs
index 8a11ce7..5d8b791 100644
--- a/src/ClaudeDo.Data/Git/GitService.cs
+++ b/src/ClaudeDo.Data/Git/GitService.cs
@@ -73,6 +73,21 @@ public sealed class GitService
         return stdout;
     }
 
+    /// <summary>
+    /// Full diff between <paramref name="baseRef"/> and the current working tree
+    /// (committed-on-branch changes + uncommitted work). Used for viewing a Claude
+    /// task's total impact relative to where the branch started.
+    /// </summary>
+    public async Task<string> GetBranchDiffAsync(string worktreePath, string baseRef, CancellationToken ct = default)
+    {
+        var (exitCode, stdout, _) = await RunGitAsync(worktreePath,
+            ["diff", baseRef], ct);
+        if (exitCode == 0 && !string.IsNullOrWhiteSpace(stdout))
+            return stdout;
+        // Fallback: whatever the worktree has vs HEAD (uncommitted only).
+        return await GetDiffAsync(worktreePath, ct);
+    }
+
     public async Task<string> DiffStatAsync(string worktreePath, string baseCommit, string headCommit, CancellationToken ct = default)
     {
         var (exitCode, stdout, stderr) = await RunGitAsync(worktreePath,
@@ -93,6 +108,41 @@ public sealed class GitService
             throw new InvalidOperationException($"git worktree remove failed (exit {exitCode}): {stderr}");
     }
 
+    public async Task<List<string>> ListWorktreePathsForBranchAsync(string repoDir, string branchName, CancellationToken ct = default)
+    {
+        var (exitCode, stdout, _) = await RunGitAsync(repoDir, ["worktree", "list", "--porcelain"], ct);
+        if (exitCode != 0) return new();
+
+        var target = $"refs/heads/{branchName}";
+        var paths = new List<string>();
+        string? currentPath = null;
+        foreach (var raw in stdout.Split('\n'))
+        {
+            var line = raw.TrimEnd('\r');
+            if (line.StartsWith("worktree ", StringComparison.Ordinal))
+            {
+                currentPath = line["worktree ".Length..].Trim();
+            }
+            else if (line.StartsWith("branch ", StringComparison.Ordinal))
+            {
+                var b = line["branch ".Length..].Trim();
+                if (b == target && currentPath is not null) paths.Add(currentPath);
+            }
+            else if (string.IsNullOrWhiteSpace(line))
+            {
+                currentPath = null;
+            }
+        }
+        return paths;
+    }
+
+    public async Task WorktreePruneAsync(string repoDir, CancellationToken ct = default)
+    {
+        var (exitCode, _, stderr) = await RunGitAsync(repoDir, ["worktree", "prune"], ct);
+        if (exitCode != 0)
+            throw new InvalidOperationException($"git worktree prune failed (exit {exitCode}): {stderr}");
+    }
+
     public async Task BranchDeleteAsync(string repoDir, string branchName, bool force = false, CancellationToken ct = default)
     {
         var flag = force ? "-D" : "-d";
diff --git a/src/ClaudeDo.Data/Repositories/WorktreeRepository.cs b/src/ClaudeDo.Data/Repositories/WorktreeRepository.cs
index 39bf109..6499aa5 100644
--- a/src/ClaudeDo.Data/Repositories/WorktreeRepository.cs
+++ b/src/ClaudeDo.Data/Repositories/WorktreeRepository.cs
@@ -40,4 +40,17 @@ public sealed class WorktreeRepository
     {
         await _context.Worktrees.Where(w => w.TaskId == taskId).ExecuteDeleteAsync(ct);
     }
+
+    public async Task<List<WorktreeEntity>> GetAllAsync(CancellationToken ct = default)
+    {
+        return await _context.Worktrees.AsNoTracking().ToListAsync(ct);
+    }
+
+    public async Task<List<WorktreeEntity>> GetByStatesAsync(
+        IReadOnlyCollection<WorktreeState> states, CancellationToken ct = default)
+    {
+        return await _context.Worktrees.AsNoTracking()
+            .Where(w => states.Contains(w.State))
+            .ToListAsync(ct);
+    }
 }
diff --git a/src/ClaudeDo.Worker/Program.cs b/src/ClaudeDo.Worker/Program.cs
index fbf8c9a..bdc61b0 100644
--- a/src/ClaudeDo.Worker/Program.cs
+++ b/src/ClaudeDo.Worker/Program.cs
@@ -29,6 +29,7 @@ builder.Services.AddSingleton<GitService>();
 builder.Services.AddSingleton<WorktreeManager>();
 builder.Services.AddSingleton<ClaudeArgsBuilder>();
 builder.Services.AddSingleton<TaskRunner>();
+builder.Services.AddSingleton<WorktreeMaintenanceService>();
 
 // Agent file management.
 var agentsDir = Path.Combine(ClaudeDo.Data.Paths.AppDataRoot(), "agents");
diff --git a/src/ClaudeDo.Worker/Runner/WorktreeManager.cs b/src/ClaudeDo.Worker/Runner/WorktreeManager.cs
index a0869f9..09aba22 100644
--- a/src/ClaudeDo.Worker/Runner/WorktreeManager.cs
+++ b/src/ClaudeDo.Worker/Runner/WorktreeManager.cs
@@ -39,8 +39,19 @@ public sealed class WorktreeManager
         var branchName = $"claudedo/{idForBranch}";
         var slug = CommitMessageBuilder.ToSlug(list.Name);
 
-        var worktreePath = _cfg.WorktreeRootStrategy.Equals("central", StringComparison.OrdinalIgnoreCase)
-            ? Path.Combine(_cfg.CentralWorktreeRoot, slug, task.Id)
+        string strategy;
+        string? centralRoot;
+        using (var settingsCtx = _dbFactory.CreateDbContext())
+        {
+            var settings = await new AppSettingsRepository(settingsCtx).GetAsync(ct);
+            strategy = settings.WorktreeStrategy;
+            centralRoot = !string.IsNullOrWhiteSpace(settings.CentralWorktreeRoot)
+                ? settings.CentralWorktreeRoot
+                : _cfg.CentralWorktreeRoot;
+        }
+
+        var worktreePath = strategy.Equals("central", StringComparison.OrdinalIgnoreCase)
+            ? Path.Combine(centralRoot ?? _cfg.CentralWorktreeRoot, slug, task.Id)
             : Path.Combine(Path.GetDirectoryName(workingDir)!, ".claudedo-worktrees", slug, task.Id);
 
         worktreePath = Path.GetFullPath(worktreePath);
@@ -48,12 +59,43 @@ public sealed class WorktreeManager
         // 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);
+        // Create the worktree. If a stale branch from a previous run remains
+        // (e.g. after force-remove), delete it and retry once.
+        try
+        {
+            await _git.WorktreeAddAsync(workingDir, branchName, worktreePath, baseCommit, ct);
+        }
+        catch (InvalidOperationException ex) when (ex.Message.Contains("already exists", StringComparison.OrdinalIgnoreCase))
+        {
+            _logger.LogWarning("Branch {Branch} already exists; cleaning phantom worktrees and retrying", branchName);
+
+            // Find and forcefully remove any existing worktree registered against this branch.
+            List<string> stalePaths;
+            try { stalePaths = await _git.ListWorktreePathsForBranchAsync(workingDir, branchName, ct); }
+            catch (Exception listEx)
+            {
+                _logger.LogWarning(listEx, "git worktree list failed during self-heal");
+                stalePaths = new();
+            }
+            foreach (var stalePath in stalePaths)
+            {
+                try { await _git.WorktreeRemoveAsync(workingDir, stalePath, force: true, ct); }
+                catch (Exception wrEx) { _logger.LogWarning(wrEx, "Failed to remove stale worktree at {Path}", stalePath); }
+            }
+
+            try { await _git.WorktreePruneAsync(workingDir, ct); }
+            catch (Exception pruneEx) { _logger.LogWarning(pruneEx, "git worktree prune failed during self-heal"); }
+            try { await _git.BranchDeleteAsync(workingDir, branchName, force: true, ct); }
+            catch (Exception delEx) { _logger.LogWarning(delEx, "git branch -D failed during self-heal"); }
+
+            await _git.WorktreeAddAsync(workingDir, branchName, worktreePath, baseCommit, ct);
+        }
 
         // Insert worktrees row AFTER git succeeds — if git throws, no row is created.
         using var context = _dbFactory.CreateDbContext();
         var wtRepo = new WorktreeRepository(context);
+        // Drop any stale row from a prior run (force-remove may have left the DB side behind).
+        await wtRepo.DeleteAsync(task.Id, ct);
         await wtRepo.AddAsync(new WorktreeEntity
         {
             TaskId = task.Id,
diff --git a/src/ClaudeDo.Worker/Services/WorktreeMaintenanceService.cs b/src/ClaudeDo.Worker/Services/WorktreeMaintenanceService.cs
new file mode 100644
index 0000000..32e95c6
--- /dev/null
+++ b/src/ClaudeDo.Worker/Services/WorktreeMaintenanceService.cs
@@ -0,0 +1,128 @@
+using ClaudeDo.Data;
+using ClaudeDo.Data.Git;
+using ClaudeDo.Data.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace ClaudeDo.Worker.Services;
+
+public sealed class WorktreeMaintenanceService
+{
+    public sealed record CleanupResult(int Removed);
+    public sealed record ResetResult(int Removed, int TasksAffected, bool Blocked, int RunningTasks);
+
+    private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
+    private readonly GitService _git;
+    private readonly ILogger<WorktreeMaintenanceService> _logger;
+
+    public WorktreeMaintenanceService(
+        IDbContextFactory<ClaudeDoDbContext> dbFactory,
+        GitService git,
+        ILogger<WorktreeMaintenanceService> logger)
+    {
+        _dbFactory = dbFactory;
+        _git = git;
+        _logger = logger;
+    }
+
+    public async Task<CleanupResult> CleanupFinishedAsync(CancellationToken ct = default)
+    {
+        using var context = _dbFactory.CreateDbContext();
+        var rows = await (from w in context.Worktrees
+                          join t in context.Tasks on w.TaskId equals t.Id
+                          join l in context.Lists on t.ListId equals l.Id
+                          where w.State == WorktreeState.Merged || w.State == WorktreeState.Discarded
+                          select new WorktreeRow(w.TaskId, w.Path, w.BranchName, l.WorkingDir))
+                         .AsNoTracking()
+                         .ToListAsync(ct);
+
+        int removed = 0;
+        foreach (var row in rows)
+        {
+            if (await TryRemoveAsync(row, force: false, ct))
+                removed++;
+        }
+        return new CleanupResult(removed);
+    }
+
+    public async Task<ResetResult> ResetAllAsync(CancellationToken ct = default)
+    {
+        using var context = _dbFactory.CreateDbContext();
+        var running = await context.Tasks.AsNoTracking()
+            .CountAsync(t => t.Status == ClaudeDo.Data.Models.TaskStatus.Running, ct);
+        if (running > 0)
+            return new ResetResult(0, 0, Blocked: true, RunningTasks: running);
+
+        var rows = await (from w in context.Worktrees
+                          join t in context.Tasks on w.TaskId equals t.Id
+                          join l in context.Lists on t.ListId equals l.Id
+                          select new WorktreeRow(w.TaskId, w.Path, w.BranchName, l.WorkingDir))
+                         .AsNoTracking()
+                         .ToListAsync(ct);
+
+        int removed = 0;
+        foreach (var row in rows)
+        {
+            if (await TryRemoveAsync(row, force: true, ct))
+                removed++;
+        }
+        return new ResetResult(removed, rows.Count, Blocked: false, RunningTasks: 0);
+    }
+
+    private async Task<bool> TryRemoveAsync(WorktreeRow row, bool force, CancellationToken ct)
+    {
+        var repoDirExists = !string.IsNullOrWhiteSpace(row.WorkingDir) && Directory.Exists(row.WorkingDir);
+
+        if (repoDirExists)
+        {
+            try
+            {
+                await _git.WorktreeRemoveAsync(row.WorkingDir!, row.Path, force, ct);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex,
+                    "git worktree remove failed for {Path}; falling back to directory delete", row.Path);
+                try { if (Directory.Exists(row.Path)) Directory.Delete(row.Path, recursive: true); }
+                catch (Exception delEx)
+                {
+                    _logger.LogError(delEx, "Directory.Delete fallback also failed for {Path}", row.Path);
+                }
+            }
+        }
+        else
+        {
+            try { if (Directory.Exists(row.Path)) Directory.Delete(row.Path, recursive: true); }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Directory.Delete failed for {Path}", row.Path);
+            }
+        }
+
+        // Branch cleanup: otherwise rerunning the task hits "branch already exists".
+        // Prune first so git no longer thinks the branch is checked out by a phantom worktree.
+        if (repoDirExists)
+        {
+            try { await _git.WorktreePruneAsync(row.WorkingDir!, ct); }
+            catch (Exception ex) { _logger.LogWarning(ex, "git worktree prune failed for {Repo}", row.WorkingDir); }
+
+            if (!string.IsNullOrWhiteSpace(row.BranchName))
+            {
+                try
+                {
+                    await _git.BranchDeleteAsync(row.WorkingDir!, row.BranchName, force: true, ct);
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to delete branch {Branch} for worktree {Path}",
+                        row.BranchName, row.Path);
+                }
+            }
+        }
+
+        using var context = _dbFactory.CreateDbContext();
+        await context.Worktrees.Where(w => w.TaskId == row.TaskId).ExecuteDeleteAsync(ct);
+        return true;
+    }
+
+    private sealed record WorktreeRow(string TaskId, string Path, string BranchName, string? WorkingDir);
+}
diff --git a/tests/ClaudeDo.Worker.Tests/Services/WorktreeMaintenanceServiceTests.cs b/tests/ClaudeDo.Worker.Tests/Services/WorktreeMaintenanceServiceTests.cs
new file mode 100644
index 0000000..3caddaa
--- /dev/null
+++ b/tests/ClaudeDo.Worker.Tests/Services/WorktreeMaintenanceServiceTests.cs
@@ -0,0 +1,203 @@
+using ClaudeDo.Data.Git;
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Services;
+using ClaudeDo.Worker.Tests.Infrastructure;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace ClaudeDo.Worker.Tests.Services;
+
+public class WorktreeMaintenanceServiceTests : IDisposable
+{
+    private readonly List<DbFixture> _dbs = new();
+    private readonly List<GitRepoFixture> _repos = new();
+
+    private static bool GitAvailable => GitRepoFixture.IsGitAvailable();
+
+    private DbFixture NewDb() { var d = new DbFixture(); _dbs.Add(d); return d; }
+    private GitRepoFixture NewRepo() { var r = new GitRepoFixture(); _repos.Add(r); return r; }
+
+    public void Dispose()
+    {
+        foreach (var d in _dbs) try { d.Dispose(); } catch { }
+        foreach (var r in _repos) try { r.Dispose(); } catch { }
+    }
+
+    private static (ListEntity list, TaskEntity task) MakeEntities(string workingDir, ClaudeDo.Data.Models.TaskStatus status = ClaudeDo.Data.Models.TaskStatus.Done)
+    {
+        var list = new ListEntity
+        {
+            Id = Guid.NewGuid().ToString(),
+            Name = "test",
+            WorkingDir = workingDir,
+            DefaultCommitType = "feat",
+            CreatedAt = DateTime.UtcNow,
+        };
+        var task = MakeTaskForList(list.Id, status);
+        return (list, task);
+    }
+
+    private static TaskEntity MakeTaskForList(string listId, ClaudeDo.Data.Models.TaskStatus status)
+        => new TaskEntity
+        {
+            Id = Guid.NewGuid().ToString(),
+            ListId = listId,
+            Title = "t",
+            Description = null,
+            Status = status,
+            CreatedAt = DateTime.UtcNow,
+        };
+
+    private static async Task<string> CreateWorktreeAsync(GitService git, string repoDir, string taskId)
+    {
+        var wtPath = Path.Combine(Path.GetTempPath(), $"wt_{Guid.NewGuid():N}");
+        var baseCommit = await git.RevParseHeadAsync(repoDir);
+        await git.WorktreeAddAsync(repoDir, $"test/{taskId}", wtPath, baseCommit);
+        return wtPath;
+    }
+
+    [Fact]
+    public async Task CleanupFinished_Removes_Merged_And_Discarded_But_Skips_Active()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = NewRepo();
+        var git = new GitService();
+        var db = NewDb();
+
+        var (list, activeTask) = MakeEntities(repo.RepoDir);
+        var mergedTask = MakeTaskForList(list.Id, ClaudeDo.Data.Models.TaskStatus.Done);
+        var discardedTask = MakeTaskForList(list.Id, ClaudeDo.Data.Models.TaskStatus.Done);
+
+        var activeWt = await CreateWorktreeAsync(git, repo.RepoDir, activeTask.Id);
+        var mergedWt = await CreateWorktreeAsync(git, repo.RepoDir, mergedTask.Id);
+        var discardedWt = await CreateWorktreeAsync(git, repo.RepoDir, discardedTask.Id);
+
+        using (var ctx = db.CreateContext())
+        {
+            await new ListRepository(ctx).AddAsync(list);
+            var taskRepo = new TaskRepository(ctx);
+            await taskRepo.AddAsync(activeTask);
+            await taskRepo.AddAsync(mergedTask);
+            await taskRepo.AddAsync(discardedTask);
+            var wtRepo = new WorktreeRepository(ctx);
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = activeTask.Id, Path = activeWt, BranchName = $"test/{activeTask.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Active, CreatedAt = DateTime.UtcNow,
+            });
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = mergedTask.Id, Path = mergedWt, BranchName = $"test/{mergedTask.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Merged, CreatedAt = DateTime.UtcNow,
+            });
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = discardedTask.Id, Path = discardedWt, BranchName = $"test/{discardedTask.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Discarded, CreatedAt = DateTime.UtcNow,
+            });
+        }
+
+        var svc = new WorktreeMaintenanceService(
+            db.CreateFactory(), git, NullLogger<WorktreeMaintenanceService>.Instance);
+
+        var result = await svc.CleanupFinishedAsync();
+
+        Assert.Equal(2, result.Removed);
+        Assert.True(Directory.Exists(activeWt));
+        Assert.False(Directory.Exists(mergedWt));
+        Assert.False(Directory.Exists(discardedWt));
+
+        using var checkCtx = db.CreateContext();
+        var remaining = await new WorktreeRepository(checkCtx).GetAllAsync();
+        Assert.Single(remaining);
+        Assert.Equal(activeTask.Id, remaining[0].TaskId);
+    }
+
+    [Fact]
+    public async Task ResetAll_Blocked_When_Running_Task_Exists()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = NewRepo();
+        var git = new GitService();
+        var db = NewDb();
+
+        var (list, task) = MakeEntities(repo.RepoDir, status: ClaudeDo.Data.Models.TaskStatus.Running);
+        var wt = await CreateWorktreeAsync(git, repo.RepoDir, task.Id);
+
+        using (var ctx = db.CreateContext())
+        {
+            await new ListRepository(ctx).AddAsync(list);
+            await new TaskRepository(ctx).AddAsync(task);
+            await new WorktreeRepository(ctx).AddAsync(new WorktreeEntity
+            {
+                TaskId = task.Id, Path = wt, BranchName = $"test/{task.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Active, CreatedAt = DateTime.UtcNow,
+            });
+        }
+
+        var svc = new WorktreeMaintenanceService(
+            db.CreateFactory(), git, NullLogger<WorktreeMaintenanceService>.Instance);
+
+        var result = await svc.ResetAllAsync();
+
+        Assert.True(result.Blocked);
+        Assert.Equal(1, result.RunningTasks);
+        Assert.Equal(0, result.Removed);
+        Assert.True(Directory.Exists(wt));
+
+        // Cleanup
+        try { await git.WorktreeRemoveAsync(repo.RepoDir, wt, force: true); } catch { }
+    }
+
+    [Fact]
+    public async Task ResetAll_Removes_All_When_No_Running_Tasks()
+    {
+        if (!GitAvailable) { Assert.True(true, "git not available -- skipping"); return; }
+
+        var repo = NewRepo();
+        var git = new GitService();
+        var db = NewDb();
+
+        var (list, t1) = MakeEntities(repo.RepoDir, status: ClaudeDo.Data.Models.TaskStatus.Done);
+        var t2 = MakeTaskForList(list.Id, ClaudeDo.Data.Models.TaskStatus.Manual);
+
+        var wt1 = await CreateWorktreeAsync(git, repo.RepoDir, t1.Id);
+        var wt2 = await CreateWorktreeAsync(git, repo.RepoDir, t2.Id);
+
+        using (var ctx = db.CreateContext())
+        {
+            await new ListRepository(ctx).AddAsync(list);
+            var taskRepo = new TaskRepository(ctx);
+            await taskRepo.AddAsync(t1);
+            await taskRepo.AddAsync(t2);
+            var wtRepo = new WorktreeRepository(ctx);
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = t1.Id, Path = wt1, BranchName = $"test/{t1.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Active, CreatedAt = DateTime.UtcNow,
+            });
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = t2.Id, Path = wt2, BranchName = $"test/{t2.Id}",
+                BaseCommit = repo.BaseCommit, State = WorktreeState.Kept, CreatedAt = DateTime.UtcNow,
+            });
+        }
+
+        var svc = new WorktreeMaintenanceService(
+            db.CreateFactory(), git, NullLogger<WorktreeMaintenanceService>.Instance);
+
+        var result = await svc.ResetAllAsync();
+
+        Assert.False(result.Blocked);
+        Assert.Equal(2, result.Removed);
+        Assert.Equal(2, result.TasksAffected);
+        Assert.False(Directory.Exists(wt1));
+        Assert.False(Directory.Exists(wt2));
+
+        using var checkCtx = db.CreateContext();
+        var remaining = await new WorktreeRepository(checkCtx).GetAllAsync();
+        Assert.Empty(remaining);
+    }
+}