fix: show sidenav shell when layout is sidenav even with no sections

Co-authored-by: eromano <1030050+eromano@users.noreply.github.com>

lib/core/src/lib/form/components/form-renderer.component.spec.ts

@@ -1119,6 +1119,12 @@ describe('Form Renderer Component', () => {
             expect(form.hasSideNav()).toBeFalse();
         });
 
+        it('should report hasSideNav as true when layout is sidenav even with no sections', () => {
+            const form = new FormModel({ layout: 'sidenav', tabs: [], fields: [] });
+            formRendererComponent.formDefinition = form;
+            expect(form.hasSideNav()).toBeTrue();
+        });
+
         it('should default the active section to the first visible leaf node', () => {
             formRendererComponent.formDefinition = buildSideNavForm();
             expect(formRendererComponent.activeSideNavSectionId()).toBe('section-1');

lib/core/src/lib/form/components/widgets/core/form.model.ts

@@ -354,10 +354,10 @@ export class FormModel implements ProcessFormModel {
      * Indicates whether the form should be rendered using the hierarchical side navigation
      * layout instead of the classic tabs layout.
      *
-     * @returns true when the form has tabs and its layout is set to `sidenav`
+     * @returns true when the form layout is set to `sidenav`
      */
     hasSideNav(): boolean {
-        return this.layout === 'sidenav' && this.hasTabs();
+        return this.layout === 'sidenav';
     }
 
     /**