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>

public/mock/dashboard-view.json

@@ -0,0 +1,23 @@
+{
+  "registration": {
+    "bigNummer": "19012345601",
+    "naam": "Dr. A. (Anna) de Vries",
+    "beroep": "Arts",
+    "registratiedatum": "2012-09-01",
+    "geboortedatum": "1985-03-14",
+    "status": { "tag": "Geregistreerd", "herregistratieDatum": "2027-03-01" }
+  },
+  "person": {
+    "naam": "Dr. A. (Anna) de Vries",
+    "geboortedatum": "1985-03-14",
+    "adres": {
+      "straat": "Lange Voorhout 9",
+      "postcode": "2514 EA",
+      "woonplaats": "Den Haag"
+    }
+  },
+  "decisions": {
+    "eligibleForHerregistratie": true,
+    "herregistratieReason": "Registratie verloopt binnen 12 maanden (2027-03-01)."
+  }
+}