Restructure into DDD bounded contexts + functional state management

Reorganise from atomic-design-only folders into bounded contexts
(auth / registratie / herregistratie) over a shared kernel, each split into
domain / application / infrastructure / ui layers. Dependencies point inward;
the domain layer is framework-free. Path aliases (@shared/@auth/@registratie/
@herregistratie) make import direction explicit.

State management (Elm-style, native TS, no new deps):
- shared/application/store.ts — createStore(init, update): pure reducer + signal
- shared/application/remote-data.ts — add map/map2/map3/andThen combinators so
  several services fold into one RemoteData; <app-async> gains an [rd] input
- registratie/application/big-profile.store.ts — root singleton combining the
  BIG-register and BRP services via map2 into one state; holds the optimistic
  herregistratie flag shared with the dashboard
- herregistratie: machine gains a WizardMsg union + pure reduce; submit is a
  command that calls infra and dispatches the result, with optimistic update +
  rollback against the shared store
- auth: SessionStore + DigiD adapter + functional route guard; login establishes
  the session, protected routes use canActivate

Rich domain: registration.policy.ts (statusColor/label, herregistratie
eligibility, invariants); BigNummer/Postcode/Uren value objects with smart
constructors. status-badge is now domain-free (colour/label inputs).

Specs for the reducer, RemoteData combinators, and eligibility policy.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/herregistratie/ui/herregistratie-wizard/herregistratie-wizard.stories.ts

@@ -0,0 +1,28 @@
+import type { Meta, StoryObj } from '@storybook/angular';
+import { applicationConfig } from '@storybook/angular';
+import { provideHttpClient } from '@angular/common/http';
+import { HerregistratieWizardComponent } from './herregistratie-wizard.component';
+import { WizardState } from '@herregistratie/domain/herregistratie.machine';
+import { Uren } from '@registratie/domain/value-objects/uren';
+
+const validData = { uren: 4160 as Uren, punten: 200 };
+
+const meta: Meta<HerregistratieWizardComponent> = {
+  title: 'Herregistratie/Wizard',
+  component: HerregistratieWizardComponent,
+  // The wizard injects BigProfileStore (for the optimistic cross-page flag),
+  // which creates httpResources — so the story needs an HttpClient.
+  decorators: [applicationConfig({ providers: [provideHttpClient()] })],
+};
+export default meta;
+type Story = StoryObj<HerregistratieWizardComponent>;
+
+// Each story seeds one state of the machine — one render per union variant.
+export const Step1: Story = { args: { seed: { tag: 'Editing', step: 1, draft: { uren: '', punten: '' }, errors: {} } } };
+export const Step1Error: Story = {
+  args: { seed: { tag: 'Editing', step: 1, draft: { uren: 'abc', punten: '' }, errors: { uren: 'Vul een geheel aantal uren in (0 of meer).' } } satisfies WizardState },
+};
+export const Step2: Story = { args: { seed: { tag: 'Editing', step: 2, draft: { uren: '4160', punten: '' }, errors: {} } } };
+export const Submitting: Story = { args: { seed: { tag: 'Submitting', data: validData } } };
+export const Submitted: Story = { args: { seed: { tag: 'Submitted', data: validData } } };
+export const Failed: Story = { args: { seed: { tag: 'Failed', data: validData, error: 'Netwerkfout' } } };