feat(design): re-theme to CIBG Huisstijl (Bootstrap 5.2), replacing RHC/Utrecht

The portal now adheres to the CIBG design system (designsystem.cibg.nl) — a customized
Bootstrap 5.2 build — replacing the Rijkshuisstijl-Community / Utrecht theme. See ADR-0003.

- Vendor @cibg/huisstijl@3.22.0 under public/cibg-huisstijl/, loaded via a <link> in
  index.html (Storybook serves it via staticDirs). Drop the two @rijkshuisstijl-community deps.
- Token bridge in styles.scss: redefine the app's ~54 --rhc-* tokens onto CIBG/--bs-* values,
  so components keep referencing tokens (no 300+ site rewrite). System-font stack; licensed
  RO/Rijks text fonts intentionally not shipped.
- Re-skin every shared atom to Bootstrap/CIBG classes (btn, form-control, form-check-*,
  table, breadcrumb, …) keeping their input() APIs. alert is hand-rolled (CIBG drops .alert);
  local .card/.badge renamed to avoid Bootstrap collisions.
- Domain pages: drop stray rhc-*/utrecht-* classes; registration-table → table table-striped.

Verified: build green, check:tokens OK, lint clean, 174 tests pass, build-storybook OK,
and the served build loads the vendored CSS (200, .btn-primary present).

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

src/app/shared/ui/card/card.component.ts

@@ -3,13 +3,14 @@ import { HeadingComponent } from '@shared/ui/heading/heading.component';
 
 /** Molecule: a content card. Standardises the repeated card surface (white,
     subtle border, rounded, padded) so pages compose cards instead of hand-rolling
-    `<div class="rhc-card">`. Optional heading; the rest is projected. */
+    a hand-rolled card surface. Optional heading; the rest is projected.
+    Local class is .app-card (NOT Bootstrap's .card, whose padding-on-body layout differs). */
 @Component({
   selector: 'app-card',
   imports: [HeadingComponent],
   styles: [`
     :host{display:block;block-size:100%}
-    .card{
+    .app-card{
       background:var(--rhc-color-wit);
       border:var(--rhc-border-width-sm) solid var(--rhc-color-border-subtle);
       border-radius:var(--rhc-border-radius-md);
@@ -17,10 +18,10 @@ import { HeadingComponent } from '@shared/ui/heading/heading.component';
       block-size:100%;
       box-sizing:border-box;
     }
-    .card > * + *{margin-block-start:var(--rhc-space-max-md)}
+    .app-card > * + *{margin-block-start:var(--rhc-space-max-md)}
   `],
   template: `
-    <section class="card">
+    <section class="app-card">
       @if (heading()) { <app-heading [level]="level()">{{ heading() }}</app-heading> }
       <ng-content />
     </section>