feat(fp): WP-17 — app-level a11y: route focus, template lint, WCAG checklist

Adds route-change focus management (new page's h1, afterNextRender) plus
scroll-position restoration wired once in app.config.ts; angular-eslint's
templateAccessibility bundle linting every inline template via
processInlineTemplates (verified firing with a planted violation, one real
hit fixed in rich-text-editor); docs/wcag-checklist.md and Foundations/
Accessibility MDX tying the four a11y layers (axe, lint, play tests,
manual checklist) together. The checklist pass already earned its keep —
it found a real 320px overflow in aanvraag-block's warning alert.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

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

@@ -1,6 +1,6 @@
 # WP-17 — App-level a11y: route focus/scroll, template lint, WCAG checklist + MDX
 
-Status: todo
+Status: done (pending commit)
 Phase: 4 — a11y
 
 ## Why
@@ -59,11 +59,30 @@ Three app-level gaps close the WCAG story:
 
 ## Acceptance criteria
 
-- [ ] Navigating between routes moves focus to the new page's heading; scroll resets;
+- [x] 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.
-- [ ] 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.
+- [x] Template a11y rules active and _proven_ to fire; lint green.
+- [x] Checklist checked in with an initial pass filled in for the dashboard at minimum.
+- [x] `a11y.mdx` renders; links to checklist and WP-01 skip rules.
+
+## Deviation from the original plan
+
+- Used the official `angular.configs.templateAccessibility` bundle (11 rules) instead of
+  hand-listing the 6 named in this WP's Decisions — it's a strict superset (includes
+  `no-autofocus`, `no-distracting-elements`, `mouse-events-have-key-events`,
+  `role-has-required-aria`, `table-scope` on top of the 6 named), maintained upstream,
+  and is exactly what `@angular-eslint/schematics`' own generated config uses for this
+  setup. Less code to hand-maintain, same coverage plus more.
+- The dashboard's checklist pass surfaced a **real bug**: `aanvraag-block`'s warning
+  `app-alert` (two `app-button` actions) overflows the viewport at 320px — its
+  `.feedback` flex row doesn't wrap. Documented in `docs/wcag-checklist.md` with the
+  root cause, **not fixed** — fixing live component CSS found via the checklist is the
+  "full manual audit" scope this WP's Out-of-scope section explicitly defers, not this
+  WP's own deliverable. Flagged here so it isn't lost.
+- "Screen reader" column left unfilled for every page — the pass available in this
+  environment was a headless-browser keyboard/DOM/computed-style check, not an actual
+  NVDA/VoiceOver run. The checklist says so explicitly rather than implying more
+  coverage than was done.
 
 ## Verification