fix(layer): keep auto-registered layer names verbatim; one sync helper

ensure_layer had started trimming the name, so an entity on " A" got a
table entry "A" it never resolves to. Register the name as given again
and drop the unused return value. The five copies of the dirty-flag check
become sync_registered_layers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/layers.rs

@@ -68,6 +68,15 @@ impl OpenCADStudio {
         self.sync_ribbon_layers();
     }
 
+    /// Pick up layers an entity edit registered on the fly (`ensure_layer`).
+    pub(super) fn sync_registered_layers(&mut self, tab: usize) {
+        if !std::mem::take(&mut self.tabs[tab].scene.layer_table_dirty) {
+            return;
+        }
+        self.tabs[tab].dirty = true;
+        self.refresh_layer_panel();
+    }
+
     pub(super) fn sync_ribbon_layers(&mut self) {
         let i = self.active_tab;
         // The Start (welcome) tab has no document — leave the layer and

src/app/plugin_host.rs

@@ -350,11 +350,7 @@ impl<'a> HostSession<'a> {
             return handle;
         }
         let handle = self.app.tabs[self.tab].scene.add_entity(entity);
-        if self.app.tabs[self.tab].scene.layer_table_dirty {
-            self.app.tabs[self.tab].scene.layer_table_dirty = false;
-            self.app.tabs[self.tab].dirty = true;
-            self.app.refresh_layer_panel();
-        }
+        self.app.sync_registered_layers(self.tab);
         self.publish_document_view();
         handle
     }
@@ -367,11 +363,7 @@ impl<'a> HostSession<'a> {
             let _ = self.normalize_scripted_entity(None, entity);
         }
         let handles = self.app.tabs[self.tab].scene.add_entities(entities);
-        if self.app.tabs[self.tab].scene.layer_table_dirty {
-            self.app.tabs[self.tab].scene.layer_table_dirty = false;
-            self.app.tabs[self.tab].dirty = true;
-            self.app.refresh_layer_panel();
-        }
+        self.app.sync_registered_layers(self.tab);
         self.publish_document_view();
         handles
     }
@@ -391,11 +383,7 @@ impl<'a> HostSession<'a> {
             EntityType::AttributeEntity(attribute) => self.replace_nested_attribute(attribute),
             entity => self.app.tabs[self.tab].scene.update_entity(entity),
         };
-        if self.app.tabs[self.tab].scene.layer_table_dirty {
-            self.app.tabs[self.tab].scene.layer_table_dirty = false;
-            self.app.tabs[self.tab].dirty = true;
-            self.app.refresh_layer_panel();
-        }
+        self.app.sync_registered_layers(self.tab);
         if ok {
             self.publish_document_view();
         }
@@ -454,11 +442,7 @@ impl<'a> HostSession<'a> {
             };
             assert!(updated);
         }
-        if self.app.tabs[self.tab].scene.layer_table_dirty {
-            self.app.tabs[self.tab].scene.layer_table_dirty = false;
-            self.app.tabs[self.tab].dirty = true;
-            self.app.refresh_layer_panel();
-        }
+        self.app.sync_registered_layers(self.tab);
         self.set_dirty();
         self.publish_document_view();
         Ok(())

src/app/properties.rs

@@ -3491,11 +3491,7 @@ handles={handles_ms:.1} panel={:.1} ribbon={ribbon_ms:.1} tail={:.1} selected={}
         if tracks_dimension_chain {
             self.tabs[i].scene.last_created_dimension = new_handle;
         }
-        if self.tabs[i].scene.layer_table_dirty {
-            self.tabs[i].scene.layer_table_dirty = false;
-            self.tabs[i].dirty = true;
-            self.refresh_layer_panel();
-        }
+        self.sync_registered_layers(i);
         new_handle
     }
 }

src/scene/entity.rs

@@ -143,17 +143,16 @@ impl Scene {
     /// layer 0. Auto-registering keeps it on its own layer (#252). Names are
     /// registered verbatim so the writer's (case-insensitive) lookup matches;
     /// the always-present default layer "0" and empty names are no-ops.
-    pub fn ensure_layer(&mut self, name: &str) -> bool {
-        let trimmed = name.trim();
-        if trimmed.is_empty() || trimmed == "0" || self.document.layers.contains(trimmed) {
-            return false;
+    /// Flags `layer_table_dirty` so the app refreshes its layer lists.
+    pub fn ensure_layer(&mut self, name: &str) {
+        if name.trim().is_empty() || self.document.layers.contains(name) {
+            return;
         }
-        let mut layer = codec::tables::Layer::new(trimmed);
+        let mut layer = codec::tables::Layer::new(name);
         layer.handle = self.document.allocate_handle();
         let _ = self.document.layers.add(layer);
-        self.invalidate_layer_dependencies(&[trimmed.to_string()]);
+        self.invalidate_layer_dependencies(&[name.to_string()]);
         self.layer_table_dirty = true;
-        true
     }
 
     pub(crate) fn ensure_app_id(&mut self, name: &str) {