Add registratie wizard, BFF dashboard-view, contracts/value-objects, and architecture docs

Checkpoint of in-progress work: the registration wizard (address prefill,
DUO diploma lookup, policy questions), decision-DTO contracts, parse-don't-
validate value objects, infrastructure adapters, plus CLAUDE.md and the
architecture/ADR docs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/registratie/infrastructure/dashboard-view.adapter.spec.ts

@@ -0,0 +1,32 @@
+import { describe, it, expect } from 'vitest';
+import { parseDashboardView } from './dashboard-view.adapter';
+
+const valid = {
+  registration: {
+    bigNummer: '19012345601',
+    naam: 'Dr. A. de Vries',
+    beroep: 'Arts',
+    registratiedatum: '2012-09-01',
+    geboortedatum: '1985-03-14',
+    status: { tag: 'Geregistreerd', herregistratieDatum: '2027-03-01' },
+  },
+  person: { naam: 'Dr. A. de Vries', geboortedatum: '1985-03-14', adres: { straat: 'X 1', postcode: '2514 EA', woonplaats: 'Den Haag' } },
+  decisions: { eligibleForHerregistratie: true, herregistratieReason: 'within window' },
+};
+
+describe('parseDashboardView (trust boundary)', () => {
+  it('maps a valid response into a DashboardView', () => {
+    const r = parseDashboardView(valid);
+    expect(r.ok).toBe(true);
+    if (r.ok) {
+      expect(r.value.profile.registration.bigNummer).toBe('19012345601');
+      expect(r.value.decisions.eligibleForHerregistratie).toBe(true);
+    }
+  });
+
+  it('rejects malformed responses instead of trusting them', () => {
+    expect(parseDashboardView(null).ok).toBe(false);
+    expect(parseDashboardView({ ...valid, registration: undefined }).ok).toBe(false);
+    expect(parseDashboardView({ ...valid, decisions: { eligibleForHerregistratie: 'yes' } }).ok).toBe(false);
+  });
+});