feat(worker): add ContinueMergeAsync to resume a conflicted merge

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Worker/Services/TaskMergeService.cs

@@ -155,6 +155,44 @@ public sealed class TaskMergeService
         CancellationToken ct)
         => MergeAsync(taskId, targetBranch, removeWorktree, commitMessage, leaveConflictsInTree: false, ct);
 
+    public async Task<MergeResult> ContinueMergeAsync(string taskId, CancellationToken ct)
+    {
+        TaskEntity task;
+        ListEntity list;
+        WorktreeEntity? wt;
+
+        using (var ctx = _dbFactory.CreateDbContext())
+        {
+            task = await new TaskRepository(ctx).GetByIdAsync(taskId, ct)
+                ?? throw new KeyNotFoundException($"Task '{taskId}' not found.");
+            list = await new ListRepository(ctx).GetByIdAsync(task.ListId, ct)
+                ?? throw new InvalidOperationException("List not found.");
+            wt = await new WorktreeRepository(ctx).GetByTaskIdAsync(taskId, ct);
+        }
+
+        if (wt is null) return Blocked("task has no worktree");
+        if (string.IsNullOrWhiteSpace(list.WorkingDir)) return Blocked("list has no working directory");
+        if (!await _git.IsMidMergeAsync(list.WorkingDir, ct))
+            return Blocked("repo is not mid-merge");
+
+        await _git.AddAllAsync(list.WorkingDir, ct);
+
+        var remaining = await _git.ListConflictedFilesAsync(list.WorkingDir, ct);
+        if (remaining.Count > 0)
+            return new MergeResult(StatusConflict, remaining, "conflicts not fully resolved");
+
+        await _git.CommitAsync(list.WorkingDir, $"Merge branch '{wt.BranchName}'", ct);
+
+        using (var ctx = _dbFactory.CreateDbContext())
+        {
+            await new WorktreeRepository(ctx).SetStateAsync(taskId, WorktreeState.Merged, ct);
+        }
+        await _broadcaster.WorktreeUpdated(taskId);
+        _logger.LogInformation("Continued merge of task {TaskId} branch {Branch}", taskId, wt.BranchName);
+
+        return new MergeResult(StatusMerged, Array.Empty<string>(), null);
+    }
+
     public async Task<MergeTargets> GetTargetsAsync(string taskId, CancellationToken ct)
     {
         TaskEntity task;

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

@@ -368,6 +368,46 @@ public class TaskMergeServiceTests : IDisposable
         Assert.Contains("switch target branch", result.ErrorMessage ?? "");
     }
 
+    [Fact]
+    public async Task ContinueMergeAsync_AfterUserResolves_CompletesMergeAndSetsWorktreeMerged()
+    {
+        if (!GitRepoFixture.IsGitAvailable()) return;
+
+        var db = NewDb();
+        var repo = NewRepo();
+        GitRepoFixture.RunGit(repo.RepoDir, "branch", "-m", "main");
+
+        File.WriteAllText(Path.Combine(repo.RepoDir, "README.md"), "# main change\n");
+        GitRepoFixture.RunGit(repo.RepoDir, "commit", "-am", "main change");
+
+        var wtPath = Path.Combine(Path.GetTempPath(), $"wt_{Guid.NewGuid():N}");
+        _wtCleanups.Add((repo.RepoDir, wtPath));
+        GitRepoFixture.RunGit(repo.RepoDir, "worktree", "add", "-b", "claudedo/t2", wtPath, repo.BaseCommit);
+        File.WriteAllText(Path.Combine(wtPath, "README.md"), "# branch change\n");
+        GitRepoFixture.RunGit(wtPath, "commit", "-am", "branch change");
+
+        var (_, task) = await SeedListAndTask(db, workingDir: repo.RepoDir, status: TaskStatus.Done);
+        await SeedWorktree(db, task.Id, wtPath, "claudedo/t2", repo.BaseCommit);
+
+        var (svc, _) = BuildService(db);
+
+        var first = await svc.MergeAsync(task.Id, "main", false, "msg",
+            leaveConflictsInTree: true, CancellationToken.None);
+        Assert.Equal(TaskMergeService.StatusConflict, first.Status);
+
+        // Simulate the user resolving the conflict.
+        File.WriteAllText(Path.Combine(repo.RepoDir, "README.md"), "# resolved\n");
+
+        var result = await svc.ContinueMergeAsync(task.Id, CancellationToken.None);
+
+        Assert.Equal(TaskMergeService.StatusMerged, result.Status);
+        Assert.False(File.Exists(Path.Combine(repo.RepoDir, ".git", "MERGE_HEAD")));
+
+        using var ctx = db.CreateContext();
+        var wt = ctx.Worktrees.Single(w => w.TaskId == task.Id);
+        Assert.Equal(WorktreeState.Merged, wt.State);
+    }
+
     [Fact]
     public async Task MergeAsync_LeaveConflicts_DoesNotAbortAndReturnsConflictFiles()
     {