fix(chat): work around WinUI session-switch crash

docs/TEST_COVERAGE.md

@@ -50,6 +50,7 @@ authoritative runtime totals.
 ### OpenClaw.Tray.Tests
 
 - **Tray UI and state** - app state, menu display/position/sizing, tray tooltip formatting, activity streams, async list loading, diagnostics contracts, markup regressions, and chat timeline/markdown handling.
+- **Chat scroll lifetime** - `ChatTimelinePresentationTests` guards the workaround for [microsoft/microsoft-ui-xaml#11865](https://github.com/microsoft/microsoft-ui-xaml/issues/11865): automatic tail navigation must not use `ItemsView.StartBringItemIntoView`, which can retain a recycled row as an invalid anchor and throw `E_INVALIDARG` during subsequent layout. Tail requests use non-animated `ScrollView` extent navigation with stable bottom anchoring. Runtime proof should repeatedly switch between large, mixed-height histories, verify the final message is visible, and check that a scrolled-up reader is not pulled to the bottom by new messages.
 - **Connection and pairing** - connection manager node connector tests, connection page approval/channel metrics/row state, operator and Windows tray node pairing approval, and gateway action transport.
 - **Settings and startup** - settings round-trip/isolation, consent and settings save, auto-start defaults, startup setup state, existing config guard policy, and local setup progress stage mapping.
 - **Onboarding and local gateway setup** - onboarding completion/chat bootstrapper/existing config guard, wizard flow/selection/error/step parsing, setup code decoding, local gateway setup diagnostics, uninstall, WSL keep-alive, and auto-pair flags.

src/OpenClaw.Tray.WinUI/Chat/ReactorItemsViewScrollController.cs

@@ -3,6 +3,7 @@
 using Microsoft.UI.Reactor.Core.V1Protocol;
 using Microsoft.UI.Reactor.Input;
 using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
 using System.Runtime.CompilerServices;
 using WinUIAnnotatedScrollBar = Microsoft.UI.Xaml.Controls.AnnotatedScrollBar;
 using WinUIItemsView = Microsoft.UI.Xaml.Controls.ItemsView;
@@ -253,7 +254,7 @@ private void QueueTailRequest(int version, TailNavigationRequest request)
 
     private bool StartTailRequest(TailNavigationRequest request)
     {
-        if (itemsView.ScrollView is not { IsLoaded: true })
+        if (itemsView.ScrollView is not { IsLoaded: true } scrollView)
             return false;
 
         if (!TailNavigationPolicy.CanExecute(
@@ -266,11 +267,12 @@ private bool StartTailRequest(TailNavigationRequest request)
         }
 
         _following = true;
-        itemsView.StartBringItemIntoView(request.Index, new BringIntoViewOptions
-        {
-            AnimationDesired = false,
-            VerticalAlignmentRatio = 1.0,
-        });
+        // Work around microsoft/microsoft-ui-xaml#11865 without retaining a row
+        // as a bring-into-view anchor across history replacement.
+        scrollView.ScrollTo(
+            scrollView.HorizontalOffset,
+            scrollView.ScrollableHeight,
+            new ScrollingScrollOptions(ScrollingAnimationMode.Disabled, ScrollingSnapPointsMode.Ignore));
         return true;
     }
 

tests/OpenClaw.Tray.Tests/ChatTimelinePresentationTests.cs

@@ -66,8 +66,11 @@ public void ReactorTimeline_UsesStableBottomAnchoringAndDiscreteTailRequests()
         Assert.Contains("itemsView.Loaded += OnLoaded", binding);
         Assert.Contains("itemsView.LayoutUpdated += OnLayoutUpdated", binding);
         Assert.Contains("itemsView.DispatcherQueue.TryEnqueue", binding);
-        Assert.Contains("itemsView.StartBringItemIntoView(", binding);
-        Assert.Contains("VerticalAlignmentRatio = 1.0", binding);
+        Assert.Contains("scrollView.ScrollTo(", binding);
+        Assert.Contains("scrollView.HorizontalOffset,", binding);
+        Assert.Contains("scrollView.ScrollableHeight,", binding);
+        Assert.Contains("ScrollingAnimationMode.Disabled, ScrollingSnapPointsMode.Ignore", binding);
+        Assert.DoesNotContain("StartBringItemIntoView", binding);
         Assert.Contains("!string.Equals(_displayedTailKey, displayedTailKey, StringComparison.Ordinal)", binding);
         Assert.Contains("_following = IsNearBottom(sender)", binding);
         Assert.Contains("_scrollView.VerticalAnchorRatio = 1.0", binding);
@@ -83,7 +86,6 @@ public void ReactorTimeline_UsesStableBottomAnchoringAndDiscreteTailRequests()
         Assert.DoesNotContain("ChangeView", binding);
         Assert.DoesNotContain("UpdateLayout", binding);
         Assert.DoesNotContain("TailSettle", binding);
-        Assert.DoesNotContain("ScrollTo(", binding);
         Assert.DoesNotContain("ScrollCompleted", binding);
         Assert.DoesNotContain("DispatcherTimer", binding);
         Assert.DoesNotContain("TextLength != current.TextLength", binding);
@@ -96,6 +98,7 @@ public void ReactorTimeline_UsesStableBottomAnchoringAndDiscreteTailRequests()
         var viewChanged = binding[viewChangedStart..tailRequestStart];
         Assert.DoesNotContain("VerticalAnchorRatio", viewChanged);
         Assert.DoesNotContain("StartBringItemIntoView", viewChanged);
+        Assert.DoesNotContain("ScrollTo(", viewChanged);
     }
 
     [Fact]