feat(behandelportal): WP-63 aanvraag status lifecycle enum

Model the full ADR-0002 lifecycle (Ingediend/InBehandeling/
MeerInfoGevraagd/Goedgekeurd/Afgewezen) as a backend enum backing the
existing AanvraagStatusDto.Tag string, and widen the FE union/parse
boundary/switches to match. Ingediend/MeerInfoGevraagd aren't reachable
yet (no behandelaar transition exists) — that's WP-65. Zero DTO shape
change, so gen:api has no drift.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/project/backlog/README.md

@@ -113,7 +113,7 @@ for its existing violations, so every WP ends green.
 | [WP-60](WP-60-write-divergence-resilience.md)          | Write-divergence resilience (local + ZGW writes)                                   | 10 · OpenZaak hardening     | done   |
 | [WP-61](WP-61-behandelportal-bootstrap.md)             | Bootstrap the behandelportal app                                                   | 11 · Behandelportal         | done   |
 | [WP-62](WP-62-medewerker-identity-authz.md)            | Backend: medewerker caller identity + authz seam                                   | 11 · Behandelportal         | done   |
-| [WP-63](WP-63-aanvraag-status-lifecycle.md)            | Backend: aanvraag status lifecycle as a published DTO                              | 11 · Behandelportal         | todo   |
+| [WP-63](WP-63-aanvraag-status-lifecycle.md)            | Backend: aanvraag status lifecycle as a published DTO                              | 11 · Behandelportal         | done   |
 | [WP-64](WP-64-behandelportal-werkvoorraad.md)          | Behandelportal: werkvoorraad (queue) screen                                        | 11 · Behandelportal         | todo   |
 | [WP-65](WP-65-behandelportal-beoordeling.md)           | Behandelportal: zaak detail + beoordeling (decision) screen                        | 11 · Behandelportal         | todo   |
 | [WP-66](WP-66-behandelportal-openzaak-write.md)        | Wire the decision into OpenZaak                                                    | 11 · Behandelportal         | todo   |

docs/project/backlog/WP-63-aanvraag-status-lifecycle.md

@@ -1,6 +1,6 @@
 # WP-63 — Backend: aanvraag status lifecycle as a published DTO
 
-Status: todo
+Status: done
 Phase: 11 — Behandelportal
 
 ## Why
@@ -48,10 +48,27 @@ read (this WP), the behandelportal needs it as the thing it advances (WP-65).
 
 ## Acceptance criteria
 
-- [ ] Backend publishes the full status lifecycle value on the existing aanvraag DTO.
-- [ ] `npm run gen:api` leaves no drift; SSP's existing "pending" display is unchanged in
+- [x] Backend publishes the full status lifecycle value on the existing aanvraag DTO.
+- [x] `npm run gen:api` leaves no drift; SSP's existing "pending" display is unchanged in
       behavior, now backed by the real status.
-- [ ] `dotnet test` + `npm run ci` green.
+- [x] `dotnet test` + `npm run ci` green.
+
+## Outcome
+
+Implemented as a pure type-system widening, not a behavior change: `AanvraagStatusTag`
+(`Ingediend | InBehandeling | MeerInfoGevraagd | Goedgekeurd | Afgewezen`) is a new C# enum
+backing `Mappers.ToStatusDto`'s existing string literals — `AanvraagStatusDto.Tag` stays a
+plain string, so the OpenAPI schema (and `npm run gen:api`) don't change at all, satisfying
+"zero required FE behavior change" trivially. `Ingediend`/`MeerInfoGevraagd` aren't reachable
+from any code path yet (no behandelaar action exists to produce them) — that's WP-65's
+transition endpoint, exactly per this WP's own Risks note. The FE `AanvraagStatus` union,
+`parseAanvraagStatus`, `statusLabel`/`submittedRow`/`detailRows`, `blockActions`, and the
+dashboard's sort order were all widened to the two new tags so TypeScript's exhaustiveness
+checking forces every switch to handle them once WP-65 starts emitting them.
+`big-profile.store.ts`'s `pendingHerregistratie` was deliberately left untouched — it's a
+pure client-side optimistic UI flag unrelated to any DTO field (not what the WP's "Why"
+section implied), and the decision text's "or kept as a computed convenience" explicitly
+allows this.
 
 ## Verification