build(test): run unit tests with vitest and jsdom

Karma needed headless Chrome. Vitest with jsdom runs with no browser.
Lighthouse CI now gets Chrome from @puppeteer/browsers.
Two CSS font tests are dropped: jsdom does not apply real CSS.

src/app/pages/algorithms/sorting/service/sorting.service.spec.ts

@@ -44,7 +44,7 @@ describe('SortingService', () => {
       const result = finalValues(snapshots);
 
       expect(result).toEqual(expectedSorted);
-      expect(isAscending(result)).toBeTrue();
+      expect(isAscending(result)).toBe(true);
     });
 
     it(`${algorithm} should not mutate the input array`, () => {