feat(ui): collapse parent task rows by default with granular row sync

src/ClaudeDo.Ui/Design/IslandStyles.axaml

@@ -88,6 +88,10 @@
     <!-- Icon.ArrowOut — filled arrow for "open external" button -->
     <StreamGeometry x:Key="Icon.ArrowOut">M13 4 H20 V11 H18 V7.4 L11.4 14 L10 12.6 L16.6 6 H13 Z M4 6 H10 V8 H6 V18 H16 V14 H18 V20 H4 Z</StreamGeometry>
 
+    <!-- Icon.ChevronRight / Icon.ChevronDown — filled expand/collapse chevrons (PathIcon fills) -->
+    <StreamGeometry x:Key="Icon.ChevronRight">M9 5 L16 12 L9 19 L6.8 16.8 L11.6 12 L6.8 7.2 Z</StreamGeometry>
+    <StreamGeometry x:Key="Icon.ChevronDown">M5 9 L12 16 L19 9 L16.8 6.8 L12 11.6 L7.2 6.8 Z</StreamGeometry>
+
     <!-- Icon.Text — three filled horizontal bars (paragraph / description icon) -->
     <StreamGeometry x:Key="Icon.Text">M4 6 H20 V8 H4 Z M4 11 H20 V13 H4 Z M4 16 H14 V18 H4 Z</StreamGeometry>
 

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

@@ -301,28 +301,18 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
 
     internal void Regroup()
     {
-        OverdueItems.Clear();
+        // Collapse parents that have children by default, so subtasks stay tucked away until
-        OpenItems.Clear();
+        // the user expands the row (an explicit toggle is saved and wins over this default).
-        CompletedItems.Clear();
-
-        // Auto-collapse planning parents whose every child is Done (unless the user
-        // has explicitly toggled the row — saved state wins).
         var childrenByParent = Items
             .Where(r => r.IsChild && !string.IsNullOrEmpty(r.ParentTaskId))
             .GroupBy(r => r.ParentTaskId!)
             .ToDictionary(g => g.Key, g => g.ToList());
-        foreach (var parent in Items.Where(r => r.IsPlanningParent && !r.IsChild
+        foreach (var parent in Items.Where(r => r.IsPlanningParent && !r.IsChild && !r.Done))
-                                                 && r.PlanningPhase == PlanningPhase.Finalized
-                                                 && !r.Done))
         {
             if (_expandedState.ContainsKey(parent.Id)) continue;
-            if (childrenByParent.TryGetValue(parent.Id, out var kids)
+            if (childrenByParent.TryGetValue(parent.Id, out var kids) && kids.Count > 0)
-                && kids.Count > 0
-                && kids.All(c => c.Status == TaskStatus.Done))
-            {
                 parent.IsExpanded = false;
         }
-        }
 
         // Restore IsExpanded from saved state
         foreach (var r in Items)
@@ -362,19 +352,29 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
         }
 
         var today = DateTime.Today;
+        var overdue   = new List<TaskRowViewModel>();
+        var open      = new List<TaskRowViewModel>();
+        var completed = new List<TaskRowViewModel>();
         foreach (var r in flat)
         {
             var underOpenPlanningParent = r.IsChild &&
                 flat.Any(p => p.Id == r.ParentTaskId && p.IsPlanningParent && !p.Done);
 
             if (r.Done && !underOpenPlanningParent)
-                CompletedItems.Add(r);
+                completed.Add(r);
             else if (r.ScheduledFor is { } d && d.Date < today)
-                OverdueItems.Add(r);
+                overdue.Add(r);
             else
-                OpenItems.Add(r);
+                open.Add(r);
         }
 
+        // Reconcile the bound collections in place (granular Insert/Move/Remove) rather than
+        // Clear+Add, so toggling a parent only touches its own child rows — the ItemsControl
+        // keeps every unchanged container instead of tearing the whole list down on a Reset.
+        SyncCollection(OverdueItems, overdue);
+        SyncCollection(OpenItems, open);
+        SyncCollection(CompletedItems, completed);
+
         HasOverdue     = OverdueItems.Count > 0;
         HasOpen        = OpenItems.Count > 0;
         HasCompleted   = CompletedItems.Count > 0;
@@ -500,6 +500,28 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
         coll.Move(srcIdx, finalIdx);
     }
 
+    // Reconcile a bound collection toward a target order using granular Remove/Move/Insert,
+    // so unchanged rows keep their containers (no Reset-driven full re-render).
+    private static void SyncCollection(
+        System.Collections.ObjectModel.ObservableCollection<TaskRowViewModel> dst,
+        List<TaskRowViewModel> target)
+    {
+        var keep = new HashSet<TaskRowViewModel>(target);
+        for (int i = dst.Count - 1; i >= 0; i--)
+            if (!keep.Contains(dst[i]))
+                dst.RemoveAt(i);
+
+        for (int i = 0; i < target.Count; i++)
+        {
+            var item = target[i];
+            if (i < dst.Count && ReferenceEquals(dst[i], item)) continue;
+
+            var cur = dst.IndexOf(item);
+            if (cur >= 0) dst.Move(cur, i);
+            else dst.Insert(i, item);
+        }
+    }
+
     private System.Collections.ObjectModel.ObservableCollection<TaskRowViewModel>? SectionFor(TaskRowViewModel row)
     {
         if (OverdueItems.Contains(row))   return OverdueItems;

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

@@ -87,10 +87,10 @@
                 VerticalAlignment="Center"
                 ToolTip.Tip="{loc:Tr tasks.toggleSubtasksTip}">
           <Panel>
-            <TextBlock Classes="meta" Text="▾" IsVisible="{Binding IsExpanded}"
+            <PathIcon Width="12" Height="12" Data="{StaticResource Icon.ChevronDown}"
-                       VerticalAlignment="Center" HorizontalAlignment="Center"/>
+                      Foreground="{DynamicResource TextDimBrush}" IsVisible="{Binding IsExpanded}"/>
-            <TextBlock Classes="meta" Text="▸" IsVisible="{Binding !IsExpanded}"
+            <PathIcon Width="12" Height="12" Data="{StaticResource Icon.ChevronRight}"
-                       VerticalAlignment="Center" HorizontalAlignment="Center"/>
+                      Foreground="{DynamicResource TextDimBrush}" IsVisible="{Binding !IsExpanded}"/>
           </Panel>
         </Button>
 

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

@@ -1,12 +1,7 @@
 using System.Linq;
-using Avalonia;
-using Avalonia.Animation;
-using Avalonia.Animation.Easings;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
-using Avalonia.Media;
-using Avalonia.Styling;
 using Avalonia.VisualTree;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Ui.ViewModels.Islands;
@@ -123,24 +118,4 @@ public partial class TaskRowView : UserControl
         ScheduleAnchor.Flyout?.Hide();
         _pendingScheduleRow = null;
     }
-
-    protected override async void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
-    {
-        base.OnAttachedToVisualTree(e);
-        RenderTransform = new TranslateTransform(0, 8);
-        Opacity = 0;
-        var anim = new Avalonia.Animation.Animation
-        {
-            Duration = TimeSpan.FromMilliseconds(300),
-            Easing = new CubicEaseOut(),
-            Children =
-            {
-                new KeyFrame { Cue = new Cue(0), Setters = { new Setter(OpacityProperty, 0d) } },
-                new KeyFrame { Cue = new Cue(1), Setters = { new Setter(OpacityProperty, 1d) } },
-            }
-        };
-        await anim.RunAsync(this);
-        Opacity = 1;
-        RenderTransform = null;
-    }
 }

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

@@ -168,6 +168,9 @@ public class TasksIslandRegroupTests : IDisposable
         var vm = BuildViewModel();
         await LoadAndWaitAsync(vm, UserList("list1", "Default"));
 
+        // Parents with children collapse by default; expand to surface the nested child.
+        vm.ToggleExpandCommand.Execute(vm.Items.First(r => r.Id == "p1"));
+
         // Child with Done status under an open Planning parent should NOT go to CompletedItems
         Assert.DoesNotContain(vm.CompletedItems, r => r.Id == "c1");
         // Child should appear nested (IsChild == true) in OpenItems

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

@@ -165,7 +165,7 @@ public class TasksIslandViewModelPlanningTests
         => new TaskRowViewModel { Id = id, Status = status, ParentTaskId = parentId, PlanningPhase = phase };
 
     [Fact]
-    public void ToggleExpand_CollapsesChildrenOfPlanningParent()
+    public void PlanningParentWithChildren_CollapsedByDefault_ToggleExpands()
     {
         var parent = MakeRow("p1", TaskStatus.Idle, phase: PlanningPhase.Active);
         var child1 = MakeRow("c1", TaskStatus.Idle, "p1");
@@ -173,18 +173,17 @@ public class TasksIslandViewModelPlanningTests
 
         var (vm, _) = VmFactory.Create([parent, child1, child2]);
 
-        // Initially expanded — children visible in OpenItems
+        // Collapsed by default — children hidden, parent still present
-        Assert.Contains(child1, vm.OpenItems);
-        Assert.Contains(child2, vm.OpenItems);
-
-        // Collapse the parent
-        vm.ToggleExpandCommand.Execute(parent);
-
-        // Children should no longer appear
         Assert.DoesNotContain(child1, vm.OpenItems);
         Assert.DoesNotContain(child2, vm.OpenItems);
-        // Parent still present
         Assert.Contains(parent, vm.OpenItems);
+
+        // Expand the parent
+        vm.ToggleExpandCommand.Execute(parent);
+
+        // Children now visible
+        Assert.Contains(child1, vm.OpenItems);
+        Assert.Contains(child2, vm.OpenItems);
     }
 
     [Fact]
@@ -210,20 +209,23 @@ public class TasksIslandViewModelPlanningTests
     }
 
     [Fact]
-    public void ToggleExpand_ExpandsCollapsedParentAgain()
+    public void ToggleExpand_TogglesParentExpansion()
     {
         var parent = MakeRow("p1", TaskStatus.Idle, phase: PlanningPhase.Finalized);
         var child = MakeRow("c1", TaskStatus.Idle, "p1");
 
         var (vm, _) = VmFactory.Create([parent, child]);
 
-        // Collapse
+        // Collapsed by default
-        vm.ToggleExpandCommand.Execute(parent);
         Assert.DoesNotContain(child, vm.OpenItems);
 
-        // Re-expand
+        // Expand
         vm.ToggleExpandCommand.Execute(parent);
         Assert.Contains(child, vm.OpenItems);
+
+        // Collapse again
+        vm.ToggleExpandCommand.Execute(parent);
+        Assert.DoesNotContain(child, vm.OpenItems);
     }
 
     [Fact]