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/registratie/ui/registration-summary/registration-summary.stories.ts

@@ -13,16 +13,11 @@ const base = {
 const meta: Meta<RegistrationSummaryComponent> = {
   title: 'Organisms/Registration Summary',
   component: RegistrationSummaryComponent,
-  parameters: {
-    // Structural: app-data-row's host sits between the <dl> and its <dt>/<dd> —
-    // fixed by the WP-12 Datablock rework. See docs/backlog/WP-12-datablock.md.
-    a11y: { disable: true },
-  },
 };
 export default meta;
 type Story = StoryObj<RegistrationSummaryComponent>;
 
-// Each story feeds a different union variant; the card renders only the rows
+// Each story feeds a different union variant; the datablock renders only the rows
 // that variant's data supports (note Doorgehaald has no herregistratie date).
 export const Geregistreerd: Story = {
   args: { reg: { ...base, status: { tag: 'Geregistreerd', herregistratieDatum: '2027-09-01' } } },