feat: add page surfaces and collapsible sidebar

src/render/source_layout.rs

@@ -458,8 +458,8 @@ impl NativeCallable for Collect {
                         return Err(invalid("duplicate arrangement slot"));
                     }
                     let bounds = [
-                        number(cx, *item, "x", false)?,
-                        number(cx, *item, "y", false)?,
+                        number(cx, *item, "x", true)?,
+                        number(cx, *item, "y", true)?,
                         number(cx, *item, "width", false)?,
                         number(cx, *item, "height", false)?,
                     ];
@@ -876,7 +876,7 @@ pub fn start(
             children[indices[&parent]].push(index);
         }
     }
-    let mut constraints = vec![layout::root_constraints(runtime.viewport); nodes.len()];
+    let mut constraints = vec![runtime.root_constraints(); nodes.len()];
     for index in 0..nodes.len() {
         let next = layout::child_constraints(&nodes[index], constraints[index]);
         for child in &children[index] {