feat(portal-beheer): ACL default-fill configuration editor (closes #131) (#138)

## What & why

S-15b, second of the S-15 (#16) split, on top of S-15a (#133). A beheerder edits the ACL's ZGW **default-fill** values from the beheer portal, and the next zaak is stamped with the new values — no restart.

Closes #131

### The vertical

portal → BFF `GET/PUT /beheer/default-fill` (medewerker realm + `beheerder` role) → ACL `GET/PUT /default-fill` → a runtime-mutable in-memory store the ACL reads **per zaak**.

- **ACL**: `IDefaultFillStore` / `InMemoryDefaultFillStore` (thread-safe, seeded from `Acl:Defaults`); `AclService` reads `fill.Current` per zaak (not cached at construction); `GET`/`PUT /default-fill` with required-field validation.
- **BFF**: `IAclClient` gains `GetDefaultFillAsync`/`UpdateDefaultFillAsync`; `GET`/`PUT /beheer/default-fill` behind the `beheerder` policy. OpenAPI + generated client regenerated.
- **Frontend**: a *Default-fill* editor page in the beheer app (load → edit → save, with saved/failure states) + nav between Catalogus and Default-fill.

### Scope decision → ADR-0026

Only the **three ZGW fill fields** (bronorganisatie, verantwoordelijke organisatie, vertrouwelijkheidaanduiding) are editable. The S-27 catalog-resolution keys stay **static config** — editing them would desync the zaaktype-URL cache (ADR-0021), and they're catalogus wiring, not "default fill". The store is **in-memory** (seeded from config): an edit reverts on restart. That's the reference-app-appropriate ceiling (no DB added to the stateless ACL); upgrade path documented. Recorded in **ADR-0026**.

## Verified locally

lint (`dotnet format`) ✓ · .NET unit — acl 60 / bff 45 / domain 152 / event-subscriber 19 / acceptance 17 ✓ · frontend lint+test (8 projects) ✓ · beheer build ✓. Clean full-solution build (caught + fixed the acceptance `AclService` ctor drift). TDD red→green per layer (ACL store, ACL endpoints, BFF, frontend).

## Definition of Done

- [x] Failing test committed before each implementation (red→green per layer).
- [x] Conventional Commits referencing #131.
- [ ] CI green — see note below.
- [x] Docs: ADR-0026 + S-15b demo note.
- [x] Demo note in `docs/demo-script.md`.

## Note on CI

The bulk validates in the fast jobs (lint/build/unit/frontend/mutation). The **verify-stack e2e** (incl. the new `default-fill.spec.ts`) can't go green until the pre-existing **verify-stack bring-up failure on the 1.27/2.0.0 runner** is resolved (that fails on plain `main` too — unrelated to this PR). Additive change; no existing e2e touched.

🤖 Generated with [Claude Code](https://claude.com/claude-code)Reviewed-on: #138

apps/beheer/src/app/app.html

@@ -1 +1,5 @@
+<nav aria-label="Beheer" class="utrecht-theme">
+  <a routerLink="/" routerLinkActive="active" [routerLinkActiveOptions]="{ exact: true }">Catalogus</a>
+  <a routerLink="/default-fill" routerLinkActive="active">Default-fill</a>
+</nav>
 <router-outlet></router-outlet>

apps/beheer/src/app/app.routes.ts

@@ -1,7 +1,9 @@
 import { Route } from '@angular/router';
 import { authenticatedGuard } from 'auth';
 import { CatalogusPage } from './catalogus/catalogus-page';
+import { DefaultFillPage } from './default-fill/default-fill-page';
 
 export const appRoutes: Route[] = [
   { path: '', component: CatalogusPage, canActivate: [authenticatedGuard] },
+  { path: 'default-fill', component: DefaultFillPage, canActivate: [authenticatedGuard] },
 ];

apps/beheer/src/app/default-fill/default-fill-page.html

@@ -0,0 +1,60 @@
+<main utrecht-document class="utrecht-theme">
+  <utrecht-article>
+    <utrecht-heading-1>Default-fill</utrecht-heading-1>
+    <p utrecht-paragraph>
+      De ZGW-standaardwaarden die de ACL op elke nieuwe zaak invult (ADR-0003). Een wijziging geldt
+      voor de eerstvolgende zaak.
+    </p>
+
+    @if (loading()) {
+      <p utrecht-paragraph role="status">Bezig met laden…</p>
+    } @else if (loaded()) {
+      <form (submit)="save(); $event.preventDefault()">
+        <p>
+          <label for="bronorganisatie">Bronorganisatie</label><br />
+          <input
+            id="bronorganisatie"
+            name="bronorganisatie"
+            [value]="bronorganisatie()"
+            (input)="bronorganisatie.set($any($event.target).value)"
+          />
+        </p>
+        <p>
+          <label for="verantwoordelijkeOrganisatie">Verantwoordelijke organisatie</label><br />
+          <input
+            id="verantwoordelijkeOrganisatie"
+            name="verantwoordelijkeOrganisatie"
+            [value]="verantwoordelijkeOrganisatie()"
+            (input)="verantwoordelijkeOrganisatie.set($any($event.target).value)"
+          />
+        </p>
+        <p>
+          <label for="vertrouwelijkheidaanduiding">Vertrouwelijkheidaanduiding</label><br />
+          <input
+            id="vertrouwelijkheidaanduiding"
+            name="vertrouwelijkheidaanduiding"
+            [value]="vertrouwelijkheidaanduiding()"
+            (input)="vertrouwelijkheidaanduiding.set($any($event.target).value)"
+          />
+        </p>
+        <button utrecht-button appearance="primary-action-button" type="submit" [disabled]="saving()">
+          Opslaan
+        </button>
+      </form>
+
+      @if (saved()) {
+        <p utrecht-paragraph role="status">De standaardwaarden zijn opgeslagen.</p>
+      }
+      @if (failed()) {
+        <p utrecht-paragraph role="alert">
+          Opslaan is niet gelukt. Controleer of je als beheerder bent ingelogd en probeer het opnieuw.
+        </p>
+      }
+    } @else if (failed()) {
+      <p utrecht-paragraph role="alert">
+        Kon de standaardwaarden niet laden. Controleer of je als beheerder bent ingelogd en probeer
+        het opnieuw.
+      </p>
+    }
+  </utrecht-article>
+</main>

apps/beheer/src/app/default-fill/default-fill-page.spec.ts

@@ -0,0 +1,90 @@
+import { signal } from '@angular/core';
+import { fireEvent, render, screen } from '@testing-library/angular';
+import { of, throwError } from 'rxjs';
+import { BeheerDefaultFill, BffApiV1Service } from 'api-client';
+import { AuthService } from 'auth';
+import { axe } from 'vitest-axe';
+import { DefaultFillPage } from './default-fill-page';
+
+const current: BeheerDefaultFill = {
+  bronorganisatie: '517439943',
+  verantwoordelijkeOrganisatie: '517439943',
+  vertrouwelijkheidaanduiding: 'openbaar',
+};
+
+class FakeAuth extends AuthService {
+  readonly isAuthenticated = signal(true);
+  readonly bsn = signal<string | undefined>(undefined);
+  override readonly roles = signal<readonly string[]>(['beheerder']);
+  login(): void {
+    /* not exercised */
+  }
+  logout(): void {
+    /* not exercised */
+  }
+}
+
+function setup(
+  overrides: {
+    getBeheerDefaultFill?: ReturnType<typeof vi.fn>;
+    putBeheerDefaultFill?: ReturnType<typeof vi.fn>;
+  } = {},
+) {
+  const getBeheerDefaultFill = overrides.getBeheerDefaultFill ?? vi.fn().mockReturnValue(of(current));
+  const putBeheerDefaultFill = overrides.putBeheerDefaultFill ?? vi.fn().mockReturnValue(of(undefined));
+  return {
+    getBeheerDefaultFill,
+    putBeheerDefaultFill,
+    providers: [
+      { provide: BffApiV1Service, useValue: { getBeheerDefaultFill, putBeheerDefaultFill } },
+      { provide: AuthService, useClass: FakeAuth },
+    ],
+  };
+}
+
+describe('DefaultFillPage', () => {
+  it('loads the current default-fill into the form on open', async () => {
+    const { getBeheerDefaultFill, providers } = setup();
+    await render(DefaultFillPage, { providers });
+
+    expect(getBeheerDefaultFill).toHaveBeenCalled();
+    const bron = (await screen.findByLabelText('Bronorganisatie')) as HTMLInputElement;
+    expect(bron.value).toBe('517439943');
+  });
+
+  it('saves the edited values via the BFF', async () => {
+    const { putBeheerDefaultFill, providers } = setup();
+    await render(DefaultFillPage, { providers });
+
+    const bron = (await screen.findByLabelText('Bronorganisatie')) as HTMLInputElement;
+    fireEvent.input(bron, { target: { value: '999999999' } });
+    fireEvent.click(screen.getByRole('button', { name: /opslaan/i }));
+
+    expect(putBeheerDefaultFill).toHaveBeenCalledWith(
+      expect.objectContaining({ bronorganisatie: '999999999', vertrouwelijkheidaanduiding: 'openbaar' }),
+    );
+    expect(await screen.findByText(/standaardwaarden zijn opgeslagen/i)).toBeTruthy();
+  });
+
+  it('surfaces a save failure instead of swallowing it', async () => {
+    const { providers } = setup({
+      putBeheerDefaultFill: vi.fn().mockReturnValue(throwError(() => new Error('403'))),
+    });
+    await render(DefaultFillPage, { providers });
+
+    fireEvent.click(await screen.findByRole('button', { name: /opslaan/i }));
+
+    expect(await screen.findByText(/opslaan is niet gelukt/i)).toBeTruthy();
+  });
+
+  it('has no WCAG 2.1 AA violations', async () => {
+    document.documentElement.lang = 'nl';
+    const { container } = await render(DefaultFillPage, { providers: setup().providers });
+
+    const results = await axe(container, {
+      runOnly: { type: 'tag', values: ['wcag2a', 'wcag2aa', 'wcag21a', 'wcag21aa'] },
+    });
+
+    expect(results.violations).toEqual([]);
+  });
+});

apps/beheer/src/app/default-fill/default-fill-page.ts

@@ -0,0 +1,72 @@
+import { Component, inject, signal } from '@angular/core';
+import { BeheerDefaultFill, BffApiV1Service } from 'api-client';
+import { UtrechtComponentsModule } from 'ui';
+
+/**
+ * The beheer default-fill editor (S-15b): a beheerder reads and edits the ZGW default-fill values the
+ * ACL stamps on every zaak (ADR-0003). Load and save go through the BFF (`/beheer/default-fill`),
+ * which proxies the ACL (ADR-0025). A save takes effect on the next zaak (the ACL reads it per zaak).
+ */
+@Component({
+  selector: 'app-default-fill-page',
+  imports: [UtrechtComponentsModule],
+  templateUrl: './default-fill-page.html',
+})
+export class DefaultFillPage {
+  private readonly bff = inject(BffApiV1Service);
+
+  protected readonly bronorganisatie = signal('');
+  protected readonly verantwoordelijkeOrganisatie = signal('');
+  protected readonly vertrouwelijkheidaanduiding = signal('');
+  protected readonly loading = signal(false);
+  protected readonly loaded = signal(false);
+  protected readonly saving = signal(false);
+  protected readonly failed = signal(false);
+  protected readonly saved = signal(false);
+
+  constructor() {
+    this.load();
+  }
+
+  load(): void {
+    this.loading.set(true);
+    this.failed.set(false);
+    this.saved.set(false);
+    this.bff.getBeheerDefaultFill().subscribe({
+      next: (d: BeheerDefaultFill) => {
+        this.bronorganisatie.set(d.bronorganisatie);
+        this.verantwoordelijkeOrganisatie.set(d.verantwoordelijkeOrganisatie);
+        this.vertrouwelijkheidaanduiding.set(d.vertrouwelijkheidaanduiding);
+        this.loading.set(false);
+        this.loaded.set(true);
+      },
+      error: () => {
+        this.loading.set(false);
+        this.loaded.set(true);
+        this.failed.set(true);
+      },
+    });
+  }
+
+  save(): void {
+    this.saving.set(true);
+    this.failed.set(false);
+    this.saved.set(false);
+    this.bff
+      .putBeheerDefaultFill({
+        bronorganisatie: this.bronorganisatie(),
+        verantwoordelijkeOrganisatie: this.verantwoordelijkeOrganisatie(),
+        vertrouwelijkheidaanduiding: this.vertrouwelijkheidaanduiding(),
+      })
+      .subscribe({
+        next: () => {
+          this.saving.set(false);
+          this.saved.set(true);
+        },
+        error: () => {
+          this.saving.set(false);
+          this.failed.set(true);
+        },
+      });
+  }
+}