fix(semantic): anchor mismatch, orphaned @defgroup UI, old format in ui/index.ts

- Fix INV_3: Test.Dashboard.DataGrid closing #endregion now matches opening
- Add @defgroup UI in UI.Module (orphaned @ingroup UI in 5 components)
- Fix TYPE Function → Module, @PURPOSE → @BRIEF, @SEMANTICS: → [SEMANTICS]
- Add [C:2] complexity tier

frontend/src/lib/components/dashboard/__tests__/DashboardDataGrid.test.ts

@@ -253,4 +253,4 @@ describe('DashboardDataGrid', () => {
     expect(screen.queryByText('Next')).toBeNull();
   });
 });
-// #endregion DashboardDataGridTest:Module
+// #endregion Test.Dashboard.DataGrid

frontend/src/lib/ui/index.ts

@@ -1,10 +1,9 @@
-// #region ui:Module [TYPE Function]
-//
-// @SEMANTICS: ui, components, library, atomic-design
-// @PURPOSE:   Central export point for standardized UI components.
-// @LAYER:     Atom
-//
-// @INVARIANT: All components exported here must follow Semantic Protocol.
+// #region UI.Module [C:2] [TYPE Module] [SEMANTICS ui,components,library,atoms]
+// @defgroup UI Standardized UI component library (atoms + complex widgets).
+// @ingroup UI
+// @BRIEF Central export point for standardized UI components.
+// @LAYER Atom
+// @INVARIANT All components exported here must follow Semantic Protocol.
 
 // [SECTION: EXPORTS]
 export { default as Button } from './Button.svelte';
@@ -22,4 +21,4 @@ export { default as Pagination } from './Pagination.svelte';
 export { default as ConfirmDialog } from './ConfirmDialog.svelte';
 // [/SECTION: EXPORTS]
 
-// #endregion ui:Module
+// #endregion UI.Module