feat(behandel): behandel-portal — werkbak + beoordeling (closes #13) (#87)

## What & why

Finishes **S-12 · Behandel-portal — werkbak + beoordeling**. The backend sub-slices (S-12a/b/c-1/c-2) were merged, but the slice's stated outcome — a behandel *portal* with medewerker login, a werkbak, and decide — had no frontend. This adds it.

- **`libs/auth`**: `MedewerkerAuthService` + `provideMedewerkerAuth` (Keycloak `medewerker` realm), a `roles`/`hasRole` surface on the shared `AuthService`, and a realm-roles protocol mapper so the SPA can read `behandelaar`/`teamlead` from the token. The BFF remains the security boundary (ADR-0013).
- **`apps/behandel`**: a new Nx Angular app mirroring self-service — medewerker OIDC login and a **werkbak** page listing registrations awaiting beoordeling (`GET /behandel/werkbak`) with per-row **Goedkeuren/Afwijzen** actions (`POST /behandel/registrations/{id}/decide`) that refresh the list. NL DS/Utrecht, standalone + signals.
- **e2e**: the walking-skeleton happy path now approves through the real portal (behandelaar logs in, finds the row by reference, clicks Goedkeuren) instead of the temporary admin endpoint.
- **infra/docs**: behandel service in compose (`:8142`, depends on Keycloak); added to the smoke `WAIT_SVCS` + CI log dump; `frontend-decisions.md` and `demo-script.md` updated.

Closes #13

## Definition of Done

- [x] Linked Gitea issue (above).
- [x] Failing test committed before the implementation.
- [x] Implementation makes the test pass; refactor commit if structure improved.
- [x] Conventional Commits referencing the issue (`refs #13`).
- [ ] CI green — all Gitea Actions jobs.
- [x] `docker compose up` from a fresh clone reaches green health checks within 3 minutes. *(behandel image + container verified locally; full stack gated in CI.)*
- [x] Docs updated if behaviour, contracts, or operations changed.
- [x] ADR added — ADR-0013 (merged with the backend sub-slices) already covers the wiring; no new decision here.
- [x] Demo note in `docs/demo-script.md`.

## Notes for reviewers

- Verified locally: auth + behandel + all frontend projects pass lint & unit tests (incl. axe WCAG 2.1 AA); production build green; the behandel Docker image builds and serves with the correct baked `medewerker` config + SPA fallback.
- The full compose-up smoke, e2e, and mutation are CI-gated (known local full-stack verify limits).
- **Follow-ups (not in scope):** the `WerkbakItem` contract has no citizen name (werkbak shows the BSN) — adding one is a BFF+domain contract change; and the domain's temporary admin `approve` endpoint is now unused by the e2e and could be removed.

Reviewed-on: #87

apps/behandel/src/app/app.config.ts

@@ -0,0 +1,39 @@
+import { provideHttpClient, withInterceptors } from '@angular/common/http';
+import { ApplicationConfig, provideBrowserGlobalErrorListeners } from '@angular/core';
+import { provideRouter } from '@angular/router';
+import { authInterceptor, provideMedewerkerAuth } from 'auth';
+import { appRoutes } from './app.routes';
+
+/** Environment-specific settings fetched from /config.json at startup (see main.ts). */
+export interface RuntimeConfig {
+  /** The Keycloak `medewerker` realm issuer as the browser reaches it (dev: localhost; compose: keycloak:8080). */
+  authority: string;
+}
+
+/**
+ * Route prefixes whose requests carry the medewerker token. These MUST match the **relative** URLs
+ * the api-client actually calls (same-origin via the nginx proxy) — the interceptor matches on
+ * `req.url`, which stays relative, so an absolute origin would never match and the token would go
+ * unattached. Only `/behandel/` is secured; the app calls no other endpoint group.
+ */
+export const SECURE_API_ROUTES = ['/behandel/'];
+
+/**
+ * Build the app providers from runtime config. `redirectUrl` is the app's own origin (where Keycloak
+ * redirects back). `secureRoutes` uses {@link SECURE_API_ROUTES} — relative prefixes, not the origin.
+ */
+export function appConfig(runtime: RuntimeConfig): ApplicationConfig {
+  const origin = typeof window !== 'undefined' ? window.location.origin : '/';
+  return {
+    providers: [
+      provideBrowserGlobalErrorListeners(),
+      provideRouter(appRoutes),
+      provideHttpClient(withInterceptors([authInterceptor()])),
+      provideMedewerkerAuth({
+        authority: runtime.authority,
+        redirectUrl: origin,
+        secureRoutes: SECURE_API_ROUTES,
+      }),
+    ],
+  };
+}