test(api-client): generated BFF client is exposed and calls the endpoints (refs #66)

Scaffold libs/api-client (Nx Angular lib) and generate a typed HttpClient client
from services/bff/openapi.json with orval (node-based; Angular target integrates
with HttpClient interceptors for the S-08c auth token). A failing test drives the
public API: it expects an injectable BffApiV1Service to POST /self-service/registrations
and GET /openbaar/register (via HttpClientTesting), but the lib barrel doesn't export
the client yet, so it fails. Normalise the vitest target to 'test'. Green exposes it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

libs/api-client/src/test-setup.ts

@@ -0,0 +1,5 @@
+import '@angular/compiler';
+import '@analogjs/vitest-angular/setup-snapshots';
+import { setupTestBed } from '@analogjs/vitest-angular/setup-testbed';
+
+setupTestBed({ zoneless: false });