feat(daily-prep): trigger planning from inside the prep-log window with an empty-state hint

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

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

@@ -92,4 +92,20 @@ public class DetailsIslandPrepModeTests : IDisposable
 
         Assert.NotEmpty(vm.PrepLog);
     }
+
+    [Fact]
+    public async Task PlanDayCommand_calls_worker()
+    {
+        var stub = new DefaultStub();
+        var vm = NewDetailsVm(stub);
+        await vm.PlanDayCommand.ExecuteAsync(null);
+        Assert.Equal(1, stub.RunDailyPrepNowCalls);
+    }
+
+    [Fact]
+    public void ShowPrepEmptyState_true_when_empty_and_not_running()
+    {
+        var vm = NewDetailsVm(new DefaultStub());
+        Assert.True(vm.ShowPrepEmptyState);
+    }
 }