fix(nodes): preserve open settings after replacement

src/app/shared/nodes/generic-node/generic-node.spec.ts

@@ -109,6 +109,17 @@ describe('GenericNodeComponent', () => {
     expect(fixture.nativeElement.querySelector('.llm-modal-backdrop')).not.toBeNull();
   });
 
+  it('restores open settings after a structural edit replaces the node', () => {
+    component.toggleNodeSettings();
+    expect(component.data.data.__nodeSettingsOpen).toBe(true);
+
+    // Replacement creates a new Angular component, whose local state starts closed.
+    component.nodeSettingsOpen = false;
+    (component as any).restorePersistedNodeSettingsState();
+
+    expect(component.nodeSettingsOpen).toBe(true);
+  });
+
   describe('clearing an optional number', () => {
     /** Opens the modal editor on a numeric path, as clicking the pen does. */
     function openNumericEditor(path: string, current: unknown) {

src/app/shared/nodes/generic-node/generic-node.ts

@@ -337,6 +337,7 @@ export class GenericNodeComponent implements OnDestroy {
 
     this.refreshValidationState();
     this.refreshParameterFields();
+    this.restorePersistedNodeSettingsState();
     this.restorePersistedFocusState();
     void this.loadSchemaContext();
   }
@@ -374,6 +375,7 @@ export class GenericNodeComponent implements OnDestroy {
     event?.preventDefault();
     event?.stopPropagation();
     this.nodeSettingsOpen = !this.nodeSettingsOpen;
+    this.syncPersistedNodeSettingsState();
     this.cdr.markForCheck();
   }
 
@@ -839,6 +841,18 @@ export class GenericNodeComponent implements OnDestroy {
       ?? (typeof mostSevereValue === 'string' ? mostSevereValue : null);
   }
 
+  /** A structural edit replaces the Rete node, so keep this UI-only state with its data. */
+  private restorePersistedNodeSettingsState() {
+    const nodeData = this.data?.data as Record<string, unknown> | undefined;
+    this.nodeSettingsOpen = nodeData?.['__nodeSettingsOpen'] === true;
+  }
+
+  private syncPersistedNodeSettingsState() {
+    const nodeData = this.data?.data as Record<string, unknown> | undefined;
+    if (!nodeData) return;
+    nodeData['__nodeSettingsOpen'] = this.nodeSettingsOpen;
+  }
+
   private ensureBlockConfiguration(): Record<string, any> {
     if (!this.data?.data) {
       this.data.data = {};