style: format frontend, docs and skills with prettier; add .prettierignore

One-time prettier --write so the new format:check CI gate starts green.
.prettierignore excludes generated (api-client.ts, documentation.json),
vendored (public/cibg-huisstijl), and backend (dotnet format owns it).

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

docs/backlog/WP-17-app-a11y.md

@@ -6,9 +6,10 @@ Phase: 4 — a11y
 ## Why
 
 Three app-level gaps close the WCAG story:
+
 - **No route-change focus/scroll management** — `app.config.ts` has only
   `provideRouter(routes, withViewTransitions())`; after navigation, focus stays wherever
-  it was and scroll position is unmanaged. (The wizard manages focus *within* steps; the
+  it was and scroll position is unmanaged. (The wizard manages focus _within_ steps; the
   skip link is the only cross-page mechanism.)
 - **No template a11y linting** — `@angular-eslint` is entirely absent.
 - User decision: a **manual WCAG checklist** documents what automation can't test.
@@ -60,7 +61,7 @@ Three app-level gaps close the WCAG story:
 
 - [ ] Navigating between routes moves focus to the new page's heading; scroll resets;
       view transitions still play.
-- [ ] Template a11y rules active and *proven* to fire; lint green.
+- [ ] Template a11y rules active and _proven_ to fire; lint green.
 - [ ] Checklist checked in with an initial pass filled in for the dashboard at minimum.
 - [ ] `a11y.mdx` renders; links to checklist and WP-01 skip rules.