feat(portal-self-service): implement the DigiD registration submit page (refs #67)

RegistrationPage shows the signed-in BSN and submits to the BFF via the generated
api-client, confirming with the returned reference; built from NL Design System
(Utrecht) components. Wire the guarded route + app providers (DigiD OIDC + token
interceptor + HttpClient), the NL DS theme, and lang=nl. Component tests
(Testing Library) + axe (WCAG 2.1 AA) pass; a guard test covers libs/auth. Replace
the demo eslint depConstraints (scope:shop/shared) with a permissive default.

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

apps/self-service/src/app/registration/registration-page.html

@@ -0,0 +1,22 @@
+<main utrecht-document class="utrecht-theme">
+  <utrecht-article>
+    <utrecht-heading-1>Zelfservice — BIG-registratie</utrecht-heading-1>
+
+    @if (submitted()) {
+      <p utrecht-paragraph role="status">
+        Uw registratie is ontvangen. Referentie: {{ reference() }}.
+      </p>
+    } @else {
+      <p utrecht-paragraph>U bent ingelogd met BSN {{ bsn() }}.</p>
+      <button
+        utrecht-button
+        appearance="primary-action-button"
+        type="button"
+        [disabled]="submitting()"
+        (click)="submit()"
+      >
+        Registratie indienen
+      </button>
+    }
+  </utrecht-article>
+</main>

apps/self-service/src/app/registration/registration-page.spec.ts

@@ -44,8 +44,15 @@ describe('RegistrationPage', () => {
   });
 
   it('has no WCAG 2.1 AA violations on the submit page', async () => {
+    // The portal is Dutch; the real index.html sets lang. Set it here so the document-level
+    // html-has-lang rule reflects the app, not the bare jsdom document.
+    document.documentElement.lang = 'nl';
     const { container } = await render(RegistrationPage, { providers: providers().providers });
-    const results = await axe(container);
+
+    const results = await axe(container, {
+      runOnly: { type: 'tag', values: ['wcag2a', 'wcag2aa', 'wcag21a', 'wcag21aa'] },
+    });
+
     expect(results.violations).toEqual([]);
   });
 });

apps/self-service/src/app/registration/registration-page.ts

@@ -1,9 +1,33 @@
-import { Component } from '@angular/core';
+import { Component, inject, signal } from '@angular/core';
+import { BffApiV1Service, type SubmitAccepted } from 'api-client';
+import { AuthService } from 'auth';
+import { UtrechtComponentsModule } from 'ui';
 
-// STUB (red): no bsn, no submit — the component/axe tests fail until the green commit.
+/**
+ * The self-service submit page: a signed-in zorgprofessional confirms and submits their BIG
+ * registration. The bsn comes from the DigiD token (not a form field), so this is a confirm-and-
+ * submit flow that posts to the BFF and shows the returned reference (ADR-0010; S-08c).
+ */
 @Component({
   selector: 'app-registration-page',
-  imports: [],
-  template: '',
+  imports: [UtrechtComponentsModule],
+  templateUrl: './registration-page.html',
 })
-export class RegistrationPage {}
+export class RegistrationPage {
+  private readonly auth = inject(AuthService);
+  private readonly bff = inject(BffApiV1Service);
+
+  protected readonly bsn = this.auth.bsn;
+  protected readonly submitting = signal(false);
+  protected readonly reference = signal<string | undefined>(undefined);
+  protected readonly submitted = signal(false);
+
+  submit(): void {
+    this.submitting.set(true);
+    this.bff.postSelfServiceRegistrations().subscribe((accepted: SubmitAccepted) => {
+      this.reference.set(accepted.registrationId);
+      this.submitted.set(true);
+      this.submitting.set(false);
+    });
+  }
+}