fix(cibg): address fieldset padding + atomic-design audit cleanup

Fix: address-fields shipped a scoped `fieldset { padding:0; margin:0 }` that
tied on specificity with CIBG's `.form-horizontal fieldset` and, injected later,
won — flattening the grey-box padding on "Mijn gegevens" and the registratie
wizard address step. Removed the override (kept the legend rule).

Audit cleanup (minimise atoms, converge or document near-duplicates):
- delete dead `app-card` (+ story; zero consumers, superseded by app-data-block)
  and the unused `.app-info-box` utility
- review-section raw <h2> -> app-heading; registratie-wizard lone <dl> -> app-data-block
- keep application-link's raw <h3> (vendored `.applications li a h3` chain needs
  the bare element) with an inline justification
- document the deliberate "don't merge these" verdicts in a new Convergence
  decisions table in atomic-design.mdx; record the card removal in cibg-gaps.mdx

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

src/app/registratie/ui/address-fields/address-fields.component.ts

@@ -19,14 +19,11 @@ export type AdresErrors = Partial<Record<keyof AdresValue, string>>;
 @Component({
   selector: 'app-address-fields',
   imports: [FormsModule, FormFieldComponent, TextInputComponent],
+  // No scoped `fieldset` reset here: the fieldset must keep CIBG's
+  // `.form-horizontal fieldset` grey-box padding/margin. A local `fieldset{padding:0}`
+  // would tie on specificity and (injected later) win, flattening the padding.
   styles: [
     `
-      fieldset {
-        border: 0;
-        margin: 0;
-        padding: 0;
-        min-inline-size: 0;
-      }
       legend {
         padding: 0;
         font-weight: var(--rhc-text-font-weight-semi-bold);

src/app/registratie/ui/registratie-wizard/registratie-wizard.component.ts

@@ -7,6 +7,7 @@ import { ButtonComponent } from '@shared/ui/button/button.component';
 import { AlertComponent } from '@shared/ui/alert/alert.component';
 import { SkeletonComponent } from '@shared/ui/skeleton/skeleton.component';
 import { DataRowComponent } from '@shared/ui/data-row/data-row.component';
+import { DataBlockComponent } from '@shared/ui/data-block/data-block.component';
 import { ReviewSectionComponent } from '@shared/ui/review-section/review-section.component';
 import { ConfirmationComponent } from '@shared/ui/confirmation/confirmation.component';
 import {
@@ -67,6 +68,7 @@ const NL_TAALVAARDIGHEID_VRAAG = 'nl-taalvaardigheid';
     AlertComponent,
     SkeletonComponent,
     DataRowComponent,
+    DataBlockComponent,
     ReviewSectionComponent,
     ConfirmationComponent,
     WizardShellComponent,
@@ -216,14 +218,14 @@ const NL_TAALVAARDIGHEID_VRAAG = 'nl-taalvaardigheid';
                     </app-form-field>
                   </fieldset>
                 } @else if (draft().beroep) {
-                  <dl class="mb-0 app-section">
+                  <app-data-block class="app-section">
                     <div
                       app-data-row
                       i18n-key="@@regWizard.beroepAfgeleid"
                       key="Beroep (afgeleid uit diploma)"
                       [value]="draft().beroep ?? ''"
                     ></div>
-                  </dl>
+                  </app-data-block>
                 }
 
                 @if (actieveVragen(data).length) {