feat(fp): WP-13 — CIBG-gap register + hygiene + MDX

Mark every hand-rolled shared/ui surface with a `// CIBG-GAP EXTENSION:`
comment + `cibgGap` story parameter (skeleton, spinner, rich-text-editor,
wizard-shell's error summary, application-link's non-navigating row,
debug-state, status-badge, card, placeholder-chip) so deviations from the
CIBG design system are auditable. Add the register MDX
(Foundations/CIBG Gap Register), cross-linked from ADR-0003. Delete the
near-identity upload-status-banner wrapper; its one consumer now uses
<app-alert> directly (a story added to keep the info-banner state covered).

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

src/app/shared/layout/wizard-shell/wizard-shell.component.ts

@@ -32,6 +32,10 @@ export type WizardStatus = 'editing' | 'submitting' | 'submitted' | 'failed';
 @Component({
   selector: 'app-wizard-shell',
   imports: [FormsModule, ButtonComponent, AlertComponent, SpinnerComponent, StepperComponent],
+  // CIBG-GAP EXTENSION: Foutmelding — the vendored build has no error-summary/
+  // Veldvalidatie list pattern (verified absent from huisstijl.min.css); the
+  // .es-title/.es-list rules below are the hand-rolled surface, see cibg-gaps.mdx.
+  // They render inside a vendored `.feedback-error` alert (app-alert).
   styles: [
     `
       .es-title {