fix: register Chart.js components in chart-widget test

Add provideCharts(withDefaultRegisterables()) to test providers to fix
"bar is not a registered controller" error.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gugu

frontend/src/app/components/dashboards/widget-renderers/chart-widget/chart-widget.component.spec.ts

@@ -2,6 +2,7 @@ import { provideHttpClient } from '@angular/common/http';
 import { provideHttpClientTesting } from '@angular/common/http/testing';
 import { ComponentFixture, TestBed } from '@angular/core/testing';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
+import { provideCharts, withDefaultRegisterables } from 'ng2-charts';
 import { ChartWidgetComponent } from './chart-widget.component';
 
 describe('ChartWidgetComponent', () => {
@@ -11,7 +12,7 @@ describe('ChartWidgetComponent', () => {
 	beforeEach(async () => {
 		await TestBed.configureTestingModule({
 			imports: [ChartWidgetComponent, BrowserAnimationsModule],
-			providers: [provideHttpClient(), provideHttpClientTesting()],
+			providers: [provideHttpClient(), provideHttpClientTesting(), provideCharts(withDefaultRegisterables())],
 		}).compileComponents();
 
 		fixture = TestBed.createComponent(ChartWidgetComponent);