chore(deps): update Angular core/cli/animations/common/compiler/forms/platform-browser/router/service-worker 21.1.5 -> 22.0.8

Ran via ng update @angular/core@22 @angular/cli@22 (schematics applied
automatically). TypeScript bumped 5.9.3 -> 6.0.3 as a required peer.

Migrations applied:
- provideHttpClient() calls gained withXhr() where HttpXhrBackend is used
  (app.config.ts)
- optional-chaining expressions wrapped in $safeNavigationMigration()
  (language-selector.component.html)
- nullishCoalescingNotNullable/optionalChainNotNullable extended
  diagnostics disabled in tsconfig.app.json/tsconfig.spec.json (matches
  the new stricter default the migration works around)

Next: ng update @angular/cdk@22, then verify tsc/build/tests.

src/app/app.config.ts

@@ -1,6 +1,6 @@
 import { ApplicationConfig, provideBrowserGlobalErrorListeners, provideZoneChangeDetection, isDevMode } from '@angular/core';
 import { provideRouter, withInMemoryScrolling } from '@angular/router';
-import { provideHttpClient, withInterceptors } from '@angular/common/http';
+import { provideHttpClient, withInterceptors, withXhr } from '@angular/common/http';
 
 import { routes } from './app.routes';
 import { cacheInterceptor } from './interceptors/cache.interceptor';
@@ -22,7 +22,7 @@ export const appConfig: ApplicationConfig = {
       routes,
       withInMemoryScrolling({ scrollPositionRestoration: 'top' })
     ),
-    provideHttpClient(
+    provideHttpClient(withXhr(), 
       withInterceptors([mockDataInterceptor, apiBaseUrlInterceptor, apiHeadersInterceptor, adminAuthHeadersInterceptor, cacheInterceptor])
     ),
     { provide: Ed25519VerificationService, useClass: NoopEd25519VerificationService },