Rijkshuisstijl restyle + wizard fixes

Chrome: two-tier Rijksoverheid header (white brand bar + lint-blue
breadcrumb bar, route-driven), dark multi-column footer, white page
surface. Session shown via a shared SESSION_PORT token (keeps shared/
free of the auth context).

Overview ("Mijn overzicht") rebuilt to the NL Design System #392 pattern:
side-nav + "Wat moet ik regelen" task list (derived) + "Mijn registratie"
cards. New shared components: card, task-list, side-nav; pure
tasksFromProfile (+spec).

Wizards: grey form panel, connected numbered stepper, form-field
"(verplicht)" markers + styled description/error, full-width inputs.
Propagated to login, detail, change-request, address-fields.

Bug fixes:
- wizard-shell: add FormsModule so NgForm intercepts submit (wizards now
  advance; no native GET leaking choices into the URL).
- wizard-shell: error-summary links focus the field instead of navigating
  (a fragment href resolved against <base href="/"> reloaded to "/" and
  bounced to login).
- wizard-shell: error-summary focus only on the rising edge, so typing
  while errors are shown no longer scrolls the page up.

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

src/app/app.config.ts

@@ -7,6 +7,8 @@ import localeNl from '@angular/common/locales/nl';
 import { routes } from './app.routes';
 import { scenarioInterceptor } from '@shared/infrastructure/scenario.interceptor';
 import { provideApiClient } from '@shared/infrastructure/api-client.provider';
+import { SESSION_PORT } from '@shared/application/session.port';
+import { SessionStore } from '@auth/application/session.store';
 
 registerLocaleData(localeNl);
 
@@ -18,6 +20,7 @@ export const appConfig: ApplicationConfig = {
     // a query param could otherwise force errors on the live app.
     provideHttpClient(withInterceptors(isDevMode() ? [scenarioInterceptor] : [])),
     provideApiClient(),
+    { provide: SESSION_PORT, useExisting: SessionStore },
     { provide: LOCALE_ID, useValue: 'nl' },
   ]
 };