feat(daily-prep): load persisted prep log into the terminal on open

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

tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs

@@ -78,6 +78,8 @@ public abstract class StubWorkerClient : IWorkerClient
     public virtual Task<DailyNoteDto?> AddDailyNoteAsync(DateOnly day, string text) => Task.FromResult<DailyNoteDto?>(null);
     public virtual Task UpdateDailyNoteAsync(string id, string text) => Task.CompletedTask;
     public virtual Task DeleteDailyNoteAsync(string id) => Task.CompletedTask;
+    public string LastPrepLog = "";
+    public virtual Task<string> GetLastPrepLogAsync() => Task.FromResult(LastPrepLog);
 
     protected void RaisePropertyChanged(string name) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
 }

tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandPrepModeTests.cs

@@ -80,4 +80,16 @@ public class DetailsIslandPrepModeTests : IDisposable
         Assert.False(vm.IsNotesMode);
         Assert.False(vm.IsTaskDetailVisible);
     }
+
+    [Fact]
+    public async Task ShowPrep_loads_persisted_log_when_empty()
+    {
+        var stub = new DefaultStub { LastPrepLog = "{\"type\":\"assistant\",\"message\":{\"content\":[{\"type\":\"text\",\"text\":\"restored\"}]}}" };
+        var vm = NewDetailsVm(stub);
+
+        vm.ShowPrep();
+        await vm.LoadLastPrepLogIfEmptyAsync();
+
+        Assert.NotEmpty(vm.PrepLog);
+    }
 }

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

@@ -85,6 +85,7 @@ sealed class FakeWorkerClient : IWorkerClient
     public Task<DailyNoteDto?> AddDailyNoteAsync(DateOnly day, string text) => Task.FromResult<DailyNoteDto?>(null);
     public Task UpdateDailyNoteAsync(string id, string text) => Task.CompletedTask;
     public Task DeleteDailyNoteAsync(string id) => Task.CompletedTask;
+    public Task<string> GetLastPrepLogAsync() => Task.FromResult(string.Empty);
 }
 
 // ── Helper to build VM with pre-seeded Items ──────────────────────────────────