feat(cibg): WP-12 — CIBG Datablock for application data

Adopt the vendored CIBG Datablock (.data-block / .block-wrapper) as the way to
show application data:
- New app-data-block molecule (grey surface + white panel + projected rows,
  optional heading, stacked variant, aria-label) + stories.
- data-row switches to a `div[app-data-row]` attribute selector so the <dl>'s
  direct child is a native <div> (HTML5.1 dl > div > dt+dd). This makes the
  definition list axe-clean — a bare custom element between <dl> and its dt/dd
  trips axe's definition-list rule regardless of display:contents, a defect the
  dashboard shipped live. Re-enables a11y on the data-row / review-section /
  registration-summary stories (previously disabled pending this rework).
- review-section folds onto app-data-block (drops its hand-carried classes).
- registration-summary + dashboard "Persoonsgegevens (BRP)" drop app-card and
  render as datablocks; both wizards' review rows + the beroep row convert to
  the div selector.

GREEN: lint, check:tokens, 178 tests, build, build-storybook, 136 axe stories.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/shared/ui/data-block/data-block.component.ts

@@ -0,0 +1,33 @@
+import { Component, input } from '@angular/core';
+import { HeadingComponent } from '@shared/ui/heading/heading.component';
+
+/** Molecule: CIBG Huisstijl **Datablock** (designsystem.cibg.nl/componenten/datablock)
+    — THE way to show user/application data. A grey `.data-block` surface holds a white
+    `.block-wrapper` panel with a `<dl>` of projected `<app-data-row>`s. Use `stacked`
+    (`.data-block--stacked`) when labels/values are long and should stack. Replaces the
+    `app-card + dl` idiom for data views (the datablock carries its own surface, so it is
+    NOT wrapped in an `app-card` — see WP-12). When there is no visible `heading`, pass an
+    `ariaLabel` so the definition list is announced. */
+@Component({
+  selector: 'app-data-block',
+  imports: [HeadingComponent],
+  template: `
+    @if (heading()) { <app-heading [level]="level()">{{ heading() }}</app-heading> }
+    <div class="data-block" [class.data-block--stacked]="stacked()">
+      <div class="block-wrapper">
+        <dl class="mb-0" [attr.aria-label]="ariaLabel() || null">
+          <ng-content />
+        </dl>
+      </div>
+    </div>
+  `,
+})
+export class DataBlockComponent {
+  heading = input('');
+  /** Heading level when `heading` is set (default h3, matching `app-card`). */
+  level = input<1 | 2 | 3 | 4 | 5>(3);
+  /** Stacks label above value (`.data-block--stacked`) for long content. */
+  stacked = input(false);
+  /** Accessible name for the `<dl>` when there is no visible heading. */
+  ariaLabel = input('');
+}