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/ui/upload/document-upload/document-upload.component.ts

@@ -1,14 +1,14 @@
 import { Component, input, output } from '@angular/core';
 import type { DeliveryChannel, UploadState } from '@shared/upload/upload.machine';
+import { AlertComponent } from '@shared/ui/alert/alert.component';
 import { DocumentCategoryComponent } from '../document-category/document-category.component';
-import { UploadStatusBannerComponent } from '../upload-status-banner/upload-status-banner.component';
 
 /** Organism: the full document-upload step — the category list, or a load-error
     banner. Pure UI: re-exposes the category events, tagging each with its category
     where the parent needs it. The container wires these to the upload reducer. */
 @Component({
   selector: 'app-document-upload',
-  imports: [DocumentCategoryComponent, UploadStatusBannerComponent],
+  imports: [DocumentCategoryComponent, AlertComponent],
   styles: [
     `
       :host {
@@ -20,10 +20,10 @@ import { UploadStatusBannerComponent } from '../upload-status-banner/upload-stat
   ],
   template: `
     @if (state().categoriesError) {
-      <app-upload-status-banner type="error" [message]="state().categoriesError!" />
+      <app-alert type="error">{{ state().categoriesError }}</app-alert>
     } @else {
       @if (state().backgroundSyncAvailable === false && state().categories.length > 0) {
-        <app-upload-status-banner type="info" [message]="foregroundOnlyMessage" />
+        <app-alert type="info">{{ foregroundOnlyMessage }}</app-alert>
       }
       @for (c of state().categories; track c.categoryId) {
         <app-document-category