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.

tsconfig.app.json

@@ -12,5 +12,13 @@
   ],
   "exclude": [
     "src/**/*.spec.ts"
-  ]
+  ],
+  "angularCompilerOptions": {
+    "extendedDiagnostics": {
+      "checks": {
+        "nullishCoalescingNotNullable": "suppress",
+        "optionalChainNotNullable": "suppress"
+      }
+    }
+  }
 }