TASK 4 ship step 5.5: social bar bug fixes + bar on the live output — direction-snap drag (SocialBarSnap.Decide + ClearValue, local Canvas.Top was overriding the binding), fediverse nodeinfo subdomain probing + load-time heal (settable FediverseSoftware), SocialBarRenderer strip blitted above the flash via a re-read FramePump socialBar seam — 155 tests passing, 0 warnings

MainWindow.xaml.cs

@@ -254,18 +254,20 @@ public partial class MainWindow : Window
     private void OpacitySlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
         => OpacityValueText.Text = $"{Math.Round(e.NewValue * 100)}%";
 
-    // ─── Social bar drag: vertical only, snaps to top/bottom on release ───
+    // ─── Social bar drag: vertical only, direction-snaps to the top/bottom edge ───
     private const double SocialBarBottomTop = 1040;
     private bool _isDraggingSocialBar;
-    private double _socialBarGrabOffsetY;
+    private double _socialBarDragStartY;
+    private SocialBarPosition? _socialBarDragDirection;
 
     private void SocialBar_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
     {
         var bar = (FrameworkElement)sender;
         _isDraggingSocialBar = true;
+        _socialBarDragDirection = null;
         var toCanvas = CanvasGrid.TransformToVisual(bar).Inverse;
         var p = toCanvas.Transform(e.GetPosition(bar));
-        _socialBarGrabOffsetY = p.Y - Canvas.GetTop(bar);
+        _socialBarDragStartY = p.Y;
         bar.CaptureMouse();
         e.Handled = true;
     }
@@ -276,7 +278,17 @@ public partial class MainWindow : Window
         var bar = (FrameworkElement)sender;
         var toCanvas = CanvasGrid.TransformToVisual(bar).Inverse;
         var p = toCanvas.Transform(e.GetPosition(bar));
-        Canvas.SetTop(bar, Math.Clamp(p.Y - _socialBarGrabOffsetY, 0, SocialBarBottomTop));
+
+        // Derive the drag direction once it commits (past the deadzone) and keep it
+        // for the rest of the drag — the bar snaps to the edge it's being dragged
+        // toward and is never left mid-screen.
+        var direction = _socialBarDragDirection
+            ?? SocialBarSnap.Decide(p.Y - _socialBarDragStartY);
+        if (direction != null)
+        {
+            _socialBarDragDirection = direction;
+            Canvas.SetTop(bar, direction == SocialBarPosition.Top ? 0 : SocialBarBottomTop);
+        }
         e.Handled = true;
     }
 
@@ -284,11 +296,18 @@ public partial class MainWindow : Window
     {
         if (!_isDraggingSocialBar) return;
         var bar = (FrameworkElement)sender;
-        var top = Canvas.GetTop(bar);
         bar.ReleaseMouseCapture();
         _isDraggingSocialBar = false;
-        var position = top <= SocialBarBottomTop / 2.0 ? SocialBarPosition.Top : SocialBarPosition.Bottom;
-        _viewModel.SetSocialBarPosition(position);
+
+        var direction = _socialBarDragDirection
+            ?? (Canvas.GetTop(bar) <= SocialBarBottomTop / 2.0
+                ? SocialBarPosition.Top : SocialBarPosition.Bottom);
+
+        // ClearValue removes the local value Canvas.SetTop applied during the drag —
+        // a local value permanently overrides the {Binding SocialBarTop}, which is
+        // why the release snap never used to show. Clearing re-engages the binding.
+        bar.ClearValue(Canvas.TopProperty);
+        _viewModel.SetSocialBarPosition(direction);
         e.Handled = true;
     }