feat(ui): add conflict-resolution worker contract (foundation for merge rework)

src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs

@@ -43,6 +43,13 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task RejectReviewToQueueAsync(string taskId, string feedback);
     Task RejectReviewToIdleAsync(string taskId);
     Task CancelReviewAsync(string taskId);
+
+    // ── Conflict resolution (worker hub side implemented by Layer C) ──
+    Task<MergeResultDto> StartConflictMergeAsync(string taskId, string targetBranch);
+    Task<MergeConflictsDto> GetMergeConflictsAsync(string taskId);
+    Task WriteConflictResolutionAsync(string taskId, string path, string resolvedContent);
+    Task<MergeResultDto> ContinueMergeAsync(string taskId);
+    Task AbortMergeAsync(string taskId);
     Task StartPlanningSessionAsync(string taskId, CancellationToken ct = default);
     Task OpenInteractiveTerminalAsync(string taskId, CancellationToken ct = default);
     Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default);

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -269,6 +269,21 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
             "MergeTask", taskId, targetBranch, removeWorktree, commitMessage);
     }
 
+    public Task<MergeResultDto> StartConflictMergeAsync(string taskId, string targetBranch)
+        => _hub.InvokeAsync<MergeResultDto>("StartConflictMerge", taskId, targetBranch);
+
+    public Task<MergeConflictsDto> GetMergeConflictsAsync(string taskId)
+        => _hub.InvokeAsync<MergeConflictsDto>("GetMergeConflicts", taskId);
+
+    public Task WriteConflictResolutionAsync(string taskId, string path, string resolvedContent)
+        => _hub.InvokeAsync("WriteConflictResolution", taskId, path, resolvedContent);
+
+    public Task<MergeResultDto> ContinueMergeAsync(string taskId)
+        => _hub.InvokeAsync<MergeResultDto>("ContinueMerge", taskId);
+
+    public Task AbortMergeAsync(string taskId)
+        => _hub.InvokeAsync("AbortMerge", taskId);
+
     public Task<MergeTargetsDto?> GetMergeTargetsAsync(string taskId)
         => TryInvokeAsync<MergeTargetsDto>("GetMergeTargets", taskId);
 
@@ -532,6 +547,9 @@ public sealed record WorktreeResetDto(int Removed, int TasksAffected, bool Block
 public record MergeResultDto(string Status, IReadOnlyList<string> ConflictFiles, string? ErrorMessage);
 public record MergePreviewDto(string Status, IReadOnlyList<string> ConflictFiles, int ChangedFileCount);
 public record MergeTargetsDto(string DefaultBranch, IReadOnlyList<string> LocalBranches);
+public record MergeConflictsDto(string TaskId, IReadOnlyList<ConflictFileDto> Files);
+public record ConflictFileDto(string Path, IReadOnlyList<ConflictHunkDto> Hunks);
+public record ConflictHunkDto(string Ours, string Theirs, string? Base);
 public sealed record UpdateListDto(string Id, string Name, string? WorkingDir, string DefaultCommitType);
 public sealed record UpdateListConfigDto(string ListId, string? Model, string? SystemPrompt, string? AgentPath, int? MaxTurns = null);
 public sealed record UpdateTaskAgentSettingsDto(string TaskId, string? Model, string? SystemPrompt, string? AgentPath, int? MaxTurns = null);

tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs

@@ -58,6 +58,11 @@ public abstract class StubWorkerClient : IWorkerClient
     public virtual Task RejectReviewToQueueAsync(string taskId, string feedback) => Task.CompletedTask;
     public virtual Task RejectReviewToIdleAsync(string taskId) => Task.CompletedTask;
     public virtual Task CancelReviewAsync(string taskId) => Task.CompletedTask;
+    public virtual Task<MergeResultDto> StartConflictMergeAsync(string taskId, string targetBranch) => Task.FromResult(new MergeResultDto("conflict", System.Array.Empty<string>(), null));
+    public virtual Task<MergeConflictsDto> GetMergeConflictsAsync(string taskId) => Task.FromResult(new MergeConflictsDto(taskId, System.Array.Empty<ConflictFileDto>()));
+    public virtual Task WriteConflictResolutionAsync(string taskId, string path, string resolvedContent) => Task.CompletedTask;
+    public virtual Task<MergeResultDto> ContinueMergeAsync(string taskId) => Task.FromResult(new MergeResultDto("merged", System.Array.Empty<string>(), null));
+    public virtual Task AbortMergeAsync(string taskId) => Task.CompletedTask;
     public virtual Task StartPlanningSessionAsync(string taskId, CancellationToken ct = default) => Task.CompletedTask;
     public virtual Task OpenInteractiveTerminalAsync(string taskId, CancellationToken ct = default) => Task.CompletedTask;
     public virtual Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default) => Task.CompletedTask;

tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs

@@ -45,6 +45,11 @@ sealed class FakeWorkerClient : IWorkerClient
     public Task<MergeResultDto?> ApproveReviewAsync(string taskId, string targetBranch) => Task.FromResult<MergeResultDto?>(null);
     public Task<MergePreviewDto?> PreviewMergeAsync(string taskId, string targetBranch) => Task.FromResult<MergePreviewDto?>(null);
     public Task<MergeResultDto> MergeTaskAsync(string taskId, string targetBranch, bool removeWorktree, string commitMessage) => Task.FromResult(new MergeResultDto("merged", System.Array.Empty<string>(), null));
+    public Task<MergeResultDto> StartConflictMergeAsync(string taskId, string targetBranch) => Task.FromResult(new MergeResultDto("conflict", System.Array.Empty<string>(), null));
+    public Task<MergeConflictsDto> GetMergeConflictsAsync(string taskId) => Task.FromResult(new MergeConflictsDto(taskId, System.Array.Empty<ConflictFileDto>()));
+    public Task WriteConflictResolutionAsync(string taskId, string path, string resolvedContent) => Task.CompletedTask;
+    public Task<MergeResultDto> ContinueMergeAsync(string taskId) => Task.FromResult(new MergeResultDto("merged", System.Array.Empty<string>(), null));
+    public Task AbortMergeAsync(string taskId) => Task.CompletedTask;
     public Task RejectReviewToQueueAsync(string taskId, string feedback) => Task.CompletedTask;
     public Task RejectReviewToIdleAsync(string taskId) => Task.CompletedTask;
     public Task CancelReviewAsync(string taskId) => Task.CompletedTask;