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>

docs/architecture/0003-cibg-huisstijl.md

@@ -48,3 +48,7 @@ layer — not a palette swap.
   alternative (adding the CSS to `angular.json` `styles`) would force-bundle the licensed fonts we
   intentionally dropped, so we accept the warning.
 - Renaming the internal token names from `--rhc-*` to `--app-*` is possible later but out of scope.
+- Hand-rolled components (point 4) are tracked in the **CIBG gap register**
+  (`src/docs/cibg-gaps.mdx`, Storybook "Foundations/CIBG Gap Register"): every deviation from the
+  design system carries a `// CIBG-GAP EXTENSION:` marker so it's auditable rather than silently
+  drifting.