Verify Windows contextual authoring and preserve postboot evidence

crates/oa-desktop/src/behavior/source_draft.rs

@@ -562,6 +562,7 @@ mod layout_tests {
     #[derive(Default)]
     struct Geometry {
         fields: Option<Rectangle>,
+        content: Option<Rectangle>,
         name: Option<Rectangle>,
         parent: Option<Rectangle>,
         actions: Option<Rectangle>,
@@ -598,7 +599,7 @@ mod layout_tests {
             &mut self,
             id: Option<&widget::Id>,
             bounds: Rectangle,
-            _: Rectangle,
+            content: Rectangle,
             offset: Vector,
             _: &mut dyn widget::operation::Scrollable,
         ) {
@@ -609,6 +610,7 @@ mod layout_tests {
                     "Initial fields must be visible without scrolling"
                 );
                 self.fields = Some(bounds);
+                self.content = Some(content);
             }
         }
         fn text_input(
@@ -888,7 +890,9 @@ mod layout_tests {
             .add_element(
                 Kind::Entity,
                 Layer::Oa,
-                &"Northern operational responsibility 雨 ".repeat(8),
+                // Eight repetitions need not exceed a whole viewport with the
+                // platform's measured font. Exercise substantial real overflow.
+                &"Northern operational responsibility 雨 ".repeat(32),
                 None,
             )
             .unwrap();
@@ -932,7 +936,12 @@ mod layout_tests {
         assert!(parent_bounds.y + 16. <= fields.y + fields.height);
         assert!(
             parent_bounds.height > fields.height,
-            "Exercise genuinely overflowing parent text"
+            "Exercise genuinely overflowing parent text: {parent_bounds:?} in {fields:?}"
+        );
+        let content = g.content.unwrap();
+        assert!(
+            content.height > fields.height && contains(content, parent_bounds),
+            "Full parent must remain in scrollable content: {parent_bounds:?}, {content:?}, {fields:?}"
         );
         let summary = g
             .text