refactor(ipc): declare the SignalR wire DTOs once in ClaudeDo.Data

WorkerHub and IWorkerClient each carried their own copy of every record and
had already drifted — MergePreviewDto lost its verify fields on the client
side, two records disagreed on their name. They now live in Data/Wire.cs and
reach both sides via a <Using> item, so a hub signature change is a compile
error instead of a silently dropped JSON field.

tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs

@@ -45,7 +45,7 @@ public abstract class StubWorkerClient : IWorkerClient
     public int ClearMyDayCalls { get; private set; }
     public int RunDailyPrepNowCalls { get; private set; }
 
-    public virtual IReadOnlyList<ActiveTask> GetActiveTasks() => System.Array.Empty<ActiveTask>();
+    public virtual IReadOnlyList<ActiveTaskDto> GetActiveTasks() => System.Array.Empty<ActiveTaskDto>();
 
     public void RaiseTaskStarted(string slot, string taskId, DateTime startedAt) => TaskStartedEvent?.Invoke(slot, taskId, startedAt);
     public void RaiseTaskFinished(string slot, string taskId, string status, DateTime finishedAt) => TaskFinishedEvent?.Invoke(slot, taskId, status, finishedAt);