feat(design): adopt CIBG component patterns (header, forms, wizards, dashboard)

Re-skins the app's layout on top of the CIBG Huisstijl theme (previous commit) so it
matches designsystem.cibg.nl, not just its colour tokens — magenta ("robijn") header,
horizontal nav, and the CIBG component markup for forms/wizards/dashboard.

- Header: logo block + robijn titlebar (breadcrumb + user menu) + grey horizontal nav
  (4 links) replacing the dashboard side-nav; breadcrumb restyled for the titlebar
  (no background of its own — CIBG's global `header nav` rule otherwise bleeds a grey
  fill into it, fixed by scoping an override inside BreadcrumbComponent).
- Forms: form-field/radio-group/checkbox rebuilt on CIBG's horizontal `form-group row`
  / `form-check.styled` markup (label col-md-4, control col-md-8); same input() APIs.
- Wizards: stepper rebuilt as the CIBG "stappenindicator" (numbered circles, visited
  steps clickable for back-nav, title merged in); wizard-shell adopts the CIBG
  procesnavigatie button row. Back-navigation wired into all three wizard machines
  (registratie-wizard already had it; added `GaNaarStap` to intake/herregistratie
  machines, pure + spec'd).
- New shared/ui molecules: confirmation (animated bevestiging checkmark, replaces
  plain alerts on submit), review-section (controlestap sections with "Wijzigen"),
  application-list/application-link (CIBG "aanvragen" rows, replace the dashboard's
  card grid and aanvraag-block).
- Cleanup: delete side-nav and now-unused styles.scss utilities (.app-overview,
  .app-form-panel, .app-card-grid); correct design-tokens.mdx (it referenced tokens
  that no longer exist) and document the CIBG-value token bridge.

Verified: build/lint/check:tokens green, 178 tests pass (4 new GaNaarStap cases), and
manually driven end-to-end (dashboard, a full herregistratie submission through to the
confirmation screen, mobile width, keyboard focus).

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

src/app/herregistratie/domain/intake.machine.ts

@@ -156,6 +156,13 @@ export function back(s: IntakeState): IntakeState {
   return { ...s, cursor: s.cursor - 1, errors: {} };
 }
 
+/** Jump back to an earlier step to correct answers (review → step N). Forward
+    jumps are not allowed (would skip validation). */
+export function gaNaarStap(s: IntakeState, cursor: number): IntakeState {
+  if (s.tag !== 'Answering' || cursor < 0 || cursor >= s.cursor) return s;
+  return { ...s, cursor, errors: {} };
+}
+
 export function submit(s: IntakeState): IntakeState {
   if (s.tag !== 'Answering') return s;
   const r = validateAll(s.answers, s.scholingThreshold);
@@ -171,6 +178,7 @@ export type IntakeMsg =
   | { tag: 'SetAnswer'; key: keyof Answers; value: string }
   | { tag: 'Next' }
   | { tag: 'Back' }
+  | { tag: 'GaNaarStap'; cursor: number }
   | { tag: 'Submit' }
   | { tag: 'Retry' }
   | { tag: 'SubmitConfirmed' }
@@ -186,6 +194,8 @@ export function reduce(s: IntakeState, m: IntakeMsg): IntakeState {
       return next(s);
     case 'Back':
       return back(s);
+    case 'GaNaarStap':
+      return gaNaarStap(s, m.cursor);
     case 'Submit':
       return submit(s);
     case 'Retry':