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>

package.json

@@ -44,6 +44,7 @@
     "@storybook/addon-onboarding": "^10.4.6",
     "@storybook/angular": "^10.4.6",
     "@storybook/test-runner": "^0.24.4",
+    "angular-eslint": "^22.0.0",
     "axe-playwright": "^2.2.2",
     "concurrently": "^10.0.3",
     "eslint": "^10.6.0",