fix(layers): protect locked entities

Keep locked-layer objects selectable for inspection while suppressing grips, property edits, command mutations, and stale editor writes.

src/app/commands/layers.rs

@@ -399,6 +399,7 @@ impl OpenCADStudio {
                     self.tabs[i].dirty = true;
                     self.commit_layer_undo(i, undo);
                     self.refresh_layer_panel();
+                    self.refresh_properties();
                     self.command_line.push_info(crate::t!("Layer(s) locked.").as_ref());
                 }
             }
@@ -508,6 +509,7 @@ impl OpenCADStudio {
                     self.tabs[i].dirty = true;
                     self.commit_layer_undo(i, undo);
                     self.refresh_layer_panel();
+                    self.refresh_properties();
                     self.command_line.push_info(crate::t!("Layer(s) unlocked.").as_ref());
                 }
             }
@@ -686,6 +688,7 @@ impl OpenCADStudio {
                     .selected_entities()
                     .into_iter()
                     .map(|(h, _)| h)
+                    .filter(|handle| !self.tabs[i].scene.is_layer_locked(*handle))
                     .collect();
                 if handles.is_empty() {
                     use crate::modules::draw::groups::ungroup::UngroupCommand;