Preserve authored sizes during identity placement transfer

crates/oa-core/examples/auto_layout_probe.rs

@@ -899,19 +899,26 @@ fn import_placement(
     }
     let mut after = original.clone();
     let ad = after.diagrams.get_mut(&diagram).unwrap();
+    let intended: BTreeMap<_, _> = plan
+        .nodes
+        .iter()
+        .map(|node| (node.id, (node.position, node.size)))
+        .collect();
     for node in plan.nodes {
         let placed = ad
             .nodes
             .get_mut(&node.id)
             .ok_or_else(|| fail("Projected node is not stored"))?;
+        let projected_size = view.nodes.iter().find(|n| n.id == node.id).unwrap().size;
         if placed.collapsed {
-            let compact = view.nodes.iter().find(|n| n.id == node.id).unwrap().size;
-            if node.size != compact {
+            if node.size != projected_size {
                 return Err(fail(
                     "Collapsed placement plan must retain exact projected compact size; stored expanded size is preserved",
                 ));
             }
-        } else {
+        } else if node.size != projected_size {
+            // Unchanged effective size must not bake derived projection minima
+            // into authored geometry during an identity transfer.
             placed.size = node.size;
         }
         placed.position = node.position;
@@ -956,6 +963,17 @@ fn import_placement(
         }
     }
     validate_candidate(&after)?;
+    let final_view = projection::project_view(&after, diagram);
+    if final_view.nodes.len() != intended.len()
+        || final_view
+            .nodes
+            .iter()
+            .any(|node| intended.get(&node.id) != Some(&(node.position, node.size)))
+    {
+        return Err(fail(
+            "Final Rust projection differs from intended node geometry",
+        ));
+    }
     Ok(after)
 }
 fn import_placement_cli(