fix(claude-do): merge ScheduledFor als UTC speichern — geplante Tasks starten aktu

ClaudeDo-Task: ea2b5950-baff-4631-ad0d-6c156a01267e

src/ClaudeDo.Ui/ViewModels/Islands/TaskRowViewModel.cs

@@ -121,7 +121,7 @@ public sealed partial class TaskRowViewModel : ViewModelBase
     public bool HasBranch   => !string.IsNullOrWhiteSpace(Branch);
     public bool HasDiff     => DiffAdditions > 0 || DiffDeletions > 0;
     public bool HasSteps    => StepsCount > 0;
-    public bool IsOverdue   => ScheduledFor is { } d && d.Date < DateTime.Today && !Done;
+    public bool IsOverdue   => ScheduledFor is { } d && d.ToLocalTime().Date < DateTime.Today && !Done;
     public bool IsRunning   => Status == TaskStatus.Running;
     public bool IsWaitingForReview => Status == TaskStatus.WaitingForReview;
     // Parked = set aside from review: Idle but still holding its Active worktree (vs a plain Idle

src/ClaudeDo.Ui/ViewModels/Islands/TasksIslandViewModel.cs

@@ -637,7 +637,7 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
 
             if (r.Done && !underOpenPlanningParent)
                 completed.Add(r);
-            else if (r.ScheduledFor is { } d && d.Date < today)
+            else if (r.ScheduledFor is { } d && d.ToLocalTime().Date < today)
                 overdue.Add(r);
             else
                 open.Add(r);
@@ -1361,12 +1361,18 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
     public async Task SetScheduledForAsync(TaskRowViewModel row, DateTime? when)
     {
         if (row is null) return;
+        // ThemedDatePicker builds Unspecified/Local wall-clock values; the DB's UtcConverter only
+        // tags DateTimes as Utc on read, it never converts on write, so this is the one place that
+        // must turn "local wall clock" into a real UTC instant before it's persisted.
+        var whenUtc = when is { } w
+            ? (w.Kind == DateTimeKind.Utc ? w : DateTime.SpecifyKind(w, DateTimeKind.Local).ToUniversalTime())
+            : (DateTime?)null;
         await using var db = await _dbFactory.CreateDbContextAsync();
         var entity = await db.Tasks.FirstOrDefaultAsync(t => t.Id == row.Id);
         if (entity is null) return;
-        entity.ScheduledFor = when;
+        entity.ScheduledFor = whenUtc;
         await db.SaveChangesAsync();
-        row.ScheduledFor = when;
+        row.ScheduledFor = whenUtc;
         Regroup();
         UpdateSubtitle();
         TasksChanged?.Invoke(this, EventArgs.Empty);

src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs

@@ -217,7 +217,7 @@ public partial class TaskRowView : UserControl
     {
         if (DataContext is not TaskRowViewModel row) return;
         _pendingScheduleRow = row;
-        ScheduleDate.SelectedDate = row.ScheduledFor ?? DateTime.Now.AddHours(1);
+        ScheduleDate.SelectedDate = row.ScheduledFor?.ToLocalTime() ?? DateTime.Now.AddHours(1);
         ScheduleAnchor.Flyout?.ShowAt(ScheduleAnchor);
     }
 

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

@@ -346,4 +346,24 @@ public class TasksIslandRegroupTests : IDisposable
         Assert.Equal(new[] { "t2", "t3", "t1" }, vm.Items.Select(r => r.Id));
         Assert.Equal(new[] { "t2", "t3", "t1" }, vm.Rows.OfType<TaskRowViewModel>().Select(r => r.Id));
     }
+
+    [Fact]
+    public async Task SetScheduledForAsync_LocalDateTime_PersistsAsUtc()
+    {
+        await SeedTasksAsync(("t1", TaskStatus.Idle, null, 0));
+
+        var vm = BuildViewModel();
+        await LoadAndWaitAsync(vm, UserList("list1", "Default"));
+        var row = vm.Items.First(r => r.Id == "t1");
+
+        // ThemedDatePicker hands SetScheduledForAsync Local/Unspecified wall-clock values.
+        var localWhen = DateTime.SpecifyKind(new DateTime(2026, 8, 26, 15, 0, 0), DateTimeKind.Local);
+
+        await vm.SetScheduledForAsync(row, localWhen);
+
+        await using var db = NewContext();
+        var entity = await db.Tasks.FirstAsync(t => t.Id == "t1");
+        Assert.Equal(DateTimeKind.Utc, entity.ScheduledFor!.Value.Kind);
+        Assert.Equal(localWhen.ToUniversalTime(), entity.ScheduledFor!.Value);
+    }
 }