feat(portal-beheer): beheer portal + read-only catalogus viewer (closes #130) (#133)

## What & why

S-15a, the first of the S-15 (#16) split. A new **beheer** portal (medewerker realm, like behandel) shows the ZTC catalogus — the published zaaktypen — **read-only**. A beheerder logs in and sees the seeded BIG-REGISTRATIE zaaktype.

Closes #130

### The vertical

portal → BFF `GET /beheer/catalogi/zaaktypen` (medewerker realm + `beheerder` role) → ACL `GET /catalogi/zaaktypen` → ZGW Catalogi API.

- **ACL**: new read-only `GET /catalogi/zaaktypen` listing published zaaktypen (reuses the ADR-0021 Catalogi client; public-safe `identificatie`/`omschrijving`).
- **BFF**: new typed `IAclClient` + `Downstream:Acl:BaseUrl`, and `GET /beheer/catalogi/zaaktypen` behind a new `beheerder` policy (reuses the medewerker bearer scheme + realm-role lifting). OpenAPI spec + generated Angular client regenerated.
- **Keycloak**: `beheerder` realm role + `bram-beheerder` test user in the medewerker realm.
- **Frontend**: new `apps/beheer` Angular app (copied from behandel) with a read-only catalogus page; `SECURE_API_ROUTES=['/beheer/']`.
- **Infra**: `beheer` compose service (port 8143), added to `WAIT_SVCS` + CI log-dump; a Playwright e2e (beheerder login → catalogus shows BIG-REGISTRATIE).

### New boundary → ADR-0025

The BFF now reaches the **ACL directly** for the catalogus read — a new service-to-service edge (§14). The catalogus is neither a domain nor a projection concern, and §8.1 means only the ACL may read ZGW; routing through the domain would pollute it with a non-domain passthrough. §8.1/§8.3 stay intact. Recorded in **ADR-0025**.

## Definition of Done

- [x] Failing test committed before each implementation (red→green per layer: ACL, BFF, frontend).
- [x] Conventional Commits referencing #130.
- [ ] CI green — pending Gitea Actions run.
- [x] `docker compose up` brings up `beheer` (health-gated in `WAIT_SVCS`).
- [x] Docs — ADR-0025 + demo-script S-15a note.
- [x] Demo note in `docs/demo-script.md`.

## Verified locally

lint (`dotnet format`) ✓ · .NET unit (Acl 57 / Big 152 / EventSubscriber 19 / Bff 40) ✓ · frontend lint+test (8 projects) ✓ · frontend build (4 apps) ✓. Mutation ratchet: added a gateway unit test for the new `ListZaaktypenAsync` mapping so the ACL score holds. verify-stack (compose smoke + e2e) runs in CI.

## Notes for reviewers

- The BFF drops the ZGW URL from `BeheerZaaktype` (public-safe: identificatie + omschrijving only).
- The catalogus e2e asserts on the stable seeded `BIG-REGISTRATIE` (not a per-test reference), safe on the shared verify stack.
- Follow-ups: **S-15b** (#131) default-fill CRUD, **S-15c** (#132) medewerker-realm MFA.

🤖 Generated with [Claude Code](https://claude.com/claude-code)Reviewed-on: #133

tests/acceptance/Support/InMemoryZaakGateway.cs

@@ -48,4 +48,8 @@ public sealed class InMemoryZaakGateway : IZaakGateway
 
     public Task<Uri> ResolveInformatieobjecttypeUrlAsync(string omschrijving, CancellationToken ct = default)
         => Task.FromResult(ResolvedInformatieobjecttypeUrl);
+
+    public Task<IReadOnlyList<ZaaktypeSummary>> ListZaaktypenAsync(CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<ZaaktypeSummary>>(
+            [new ZaaktypeSummary("BIG-REGISTRATIE", "BIG-registratie", ResolvedZaaktypeUrl)]);
 }

tests/e2e/catalogus.spec.ts

@@ -0,0 +1,21 @@
+import { expect, test } from '@playwright/test';
+
+// S-15a walking skeleton: a beheerder logs in to the beheer portal (medewerker realm) and sees the
+// read-only ZTC catalogus. The verify stack seeds and publishes the BIG-REGISTRATIE zaaktype (the
+// same one verify-domain relies on), so it must appear in the catalogus. Runs against the shared
+// verify stack, so it asserts on that stable seeded zaaktype rather than anything test-specific.
+test('a beheerder sees the published zaaktypen in the catalogus', async ({ page }) => {
+  await page.goto('http://beheer/');
+
+  // The beheer portal redirects to the Keycloak medewerker realm login (same realm as behandel).
+  await page.locator('#username').fill('bram-beheerder');
+  await page.locator('#password').fill('test123');
+  await page.locator('#kc-login').click();
+
+  await expect(page.getByRole('heading', { name: /Catalogus/i })).toBeVisible();
+
+  // The seeded, published BIG zaaktype is shown by its business identificatie. Match the cell
+  // exactly (case-sensitive): getByText is case-insensitive, so it would also match the omschrijving
+  // cell "BIG-registratie" and trip strict mode.
+  await expect(page.getByRole('cell', { name: 'BIG-REGISTRATIE', exact: true })).toBeVisible();
+});

tests/e2e/playwright.config.ts

@@ -6,6 +6,9 @@ const baseURL = process.env.SELF_SERVICE_URL ?? 'http://self-service';
 // The behandel portal is a second origin the happy path visits (staff approve from the werkbak);
 // it needs the same insecure-origin-as-secure treatment as self-service for the PKCE login (below).
 const behandelURL = process.env.BEHANDEL_URL ?? 'http://behandel';
+// The beheer portal is a third medewerker-realm origin (the read-only catalogus viewer, S-15a); it
+// needs the same insecure-origin-as-secure treatment as the others for the PKCE login (below).
+const beheerURL = process.env.BEHEER_URL ?? 'http://beheer';
 
 export default defineConfig({
   testDir: '.',
@@ -33,7 +36,7 @@ export default defineConfig({
     channel: 'chromium',
     launchOptions: {
       args: [
-        `--unsafely-treat-insecure-origin-as-secure=${baseURL},${behandelURL}`,
+        `--unsafely-treat-insecure-origin-as-secure=${baseURL},${behandelURL},${beheerURL}`,
         // Write Chromium's shared memory to /tmp instead of the container's small /dev/shm, so a
         // large DOM/heap can't crash the renderer on the memory-constrained runner (belt-and-braces
         // alongside the single worker above).