feat(fp): WP-17 — app-level a11y: route focus, template lint, WCAG checklist

Adds route-change focus management (new page's h1, afterNextRender) plus
scroll-position restoration wired once in app.config.ts; angular-eslint's
templateAccessibility bundle linting every inline template via
processInlineTemplates (verified firing with a planted violation, one real
hit fixed in rich-text-editor); docs/wcag-checklist.md and Foundations/
Accessibility MDX tying the four a11y layers (axe, lint, play tests,
manual checklist) together. The checklist pass already earned its keep —
it found a real 320px overflow in aanvraag-block's warning alert.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/app.config.ts

@@ -4,7 +4,7 @@ import {
   isDevMode,
   provideBrowserGlobalErrorListeners,
 } from '@angular/core';
-import { provideRouter, withViewTransitions } from '@angular/router';
+import { provideRouter, withInMemoryScrolling, withViewTransitions } from '@angular/router';
 import type { ActivatedRouteSnapshot } from '@angular/router';
 import { provideHttpClient, withInterceptors } from '@angular/common/http';
 import { registerLocaleData } from '@angular/common';
@@ -16,6 +16,7 @@ import { roleInterceptor } from '@shared/infrastructure/role.interceptor';
 import { provideApiClient } from '@shared/infrastructure/api-client.provider';
 import { SESSION_PORT } from '@shared/application/session.port';
 import { SessionStore } from '@auth/application/session.store';
+import { provideRouteFocus } from '@shared/layout/route-focus';
 
 registerLocaleData(localeNl);
 
@@ -24,6 +25,7 @@ export const appConfig: ApplicationConfig = {
     provideBrowserGlobalErrorListeners(),
     provideRouter(
       routes,
+      withInMemoryScrolling({ scrollPositionRestoration: 'enabled' }),
       // Cross-fade page-to-page navigations only. A silent same-route nav — e.g.
       // draft-sync stamping `?aanvraag=<id>` into the URL mid-wizard — must NOT
       // animate: for the transition's duration Firefox's `::view-transition`
@@ -48,5 +50,6 @@ export const appConfig: ApplicationConfig = {
     provideApiClient(),
     { provide: SESSION_PORT, useExisting: SessionStore },
     { provide: LOCALE_ID, useValue: 'nl' },
+    provideRouteFocus(),
   ],
 };