Fix 7 failing click tests — clicks fire on mouse release, not press

The Click fixture helper and manual test frames only ran press-down
without a subsequent release frame. ShouldProcessClick checks
IsMouseJustReleased, so a third frame with mouseDown=false is needed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: andreakarasho

src/Clay.Test/ClayUIFixture.cs

@@ -62,12 +62,20 @@ public ReadOnlySpan<RenderCommand> RunTwoFrames(
     }
 
     /// <summary>
-    /// Simulates a click: runs frame 1 (no press), frame 2 (press down), returns frame 2 commands.
+    /// Simulates a click: runs frame 1 (establish bounds), frame 2 (press down),
+    /// frame 3 (release — triggers click). Returns frame 3 commands.
     /// The buildUi action can capture return values via closures.
     /// </summary>
     public ReadOnlySpan<RenderCommand> Click(Action buildUi, Vector2 mousePos)
     {
-        return RunTwoFrames(buildUi, mousePos, mouseDown: true);
+        // Frame 1: establish bounding boxes (no interaction)
+        RunFrame(buildUi, mousePos, mouseDown: false);
+
+        // Frame 2: press down
+        RunFrame(buildUi, mousePos, mouseDown: true);
+
+        // Frame 3: release — ShouldProcessClick fires on mouse release
+        return RunFrame(buildUi, mousePos, mouseDown: false);
     }
 
     public void Dispose()

src/Clay.Test/ClayUIListBoxComboTests.cs

@@ -59,21 +59,21 @@ public void ListBoxItem_NotClicked_ReturnsFalse()
     public void ListBoxItem_Clicked_ReturnsTrue()
     {
         bool clicked = false;
-        // First frame: establish layout
-        _fixture.RunFrame(() =>
-        {
-            ClayUI.BeginListBox("ClickList2");
-            ClayUI.ListBoxItem("Item A##cl2_a", isSelected: false);
-            ClayUI.EndListBox();
-        });
-
-        // Second frame: click on the item area (top-left region)
-        _fixture.RunFrame(() =>
+        Action buildUi = () =>
         {
             ClayUI.BeginListBox("ClickList2");
             clicked = ClayUI.ListBoxItem("Item A##cl2_a", isSelected: false);
             ClayUI.EndListBox();
-        }, mousePos: new Vector2(30, 30), mouseDown: true);
+        };
+
+        // Frame 1: establish layout
+        _fixture.RunFrame(buildUi);
+
+        // Frame 2: press down on the item
+        _fixture.RunFrame(buildUi, mousePos: new Vector2(30, 30), mouseDown: true);
+
+        // Frame 3: release — click fires on mouse release
+        _fixture.RunFrame(buildUi, mousePos: new Vector2(30, 30), mouseDown: false);
 
         Assert.True(clicked);
     }

src/Clay.Test/ClayUITreeNodeTests.cs

@@ -89,29 +89,38 @@ public void BeginTreeNode_Expanded_GeneratesChildContent()
     [Fact]
     public void TreeNode_Click_TogglesExpanded()
     {
-        bool expandedFrame2 = false;
+        bool expandedFrame3 = false;
 
-        // Frame 1: node is collapsed (default)
-        _fixture.RunFrame(() =>
+        Action buildUi = () =>
         {
             var expanded = ClayUI.BeginTreeNode("Toggle Node");
-            if (expanded) ClayUI.EndTreeNode();
-        });
+            if (expanded)
+            {
+                ClayUI.Label("Now visible");
+                ClayUI.EndTreeNode();
+            }
+        };
+
+        // Frame 1: establish bounding boxes (collapsed, no interaction)
+        _fixture.RunFrame(buildUi);
+
+        // Frame 2: press down on the node header
+        _fixture.RunFrame(buildUi, mousePos: new Vector2(30, 5), mouseDown: true);
 
-        // Frame 2: click on the node header to expand it
+        // Frame 3: release — click fires on mouse release
         _fixture.RunFrame(() =>
         {
-            expandedFrame2 = ClayUI.BeginTreeNode("Toggle Node");
-            if (expandedFrame2)
+            expandedFrame3 = ClayUI.BeginTreeNode("Toggle Node");
+            if (expandedFrame3)
             {
                 ClayUI.Label("Now visible");
                 ClayUI.EndTreeNode();
             }
         },
         mousePos: new Vector2(30, 5),
-        mouseDown: true);
+        mouseDown: false);
 
-        Assert.True(expandedFrame2, "Clicking tree node header should expand it");
+        Assert.True(expandedFrame3, "Clicking tree node header should expand it");
     }
 
     [Fact]