test: vitest unit + playwright e2e suites; fix a11y, contrast, no-JS reveal

- vitest: dictionary parity, slug-map bijection, content-schema validation, JSON-LD (23)
- playwright: both locales, language-switch mapping (incl. no-JS), CV downloads,
  form happy-path + honeypot, axe a11y on 5 templates x 2 themes (23)
- fix: raise ink-faint + light accent to meet WCAG AA 4.5:1 (axe-verified)
- fix: gate reveal animations behind html.js so content is visible without JS
  (progressive enhancement - was hidden at opacity 0); scan reduced-motion path
- fix: validate contact form before the anti-bot time-trap (no false success)
- chore: ESLint node globals, typed diagram props, resvg fontFiles, prettier pass

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

site/src/components/ui/ThemeToggle.astro

@@ -12,7 +12,7 @@ const d = useDict(locale);
 <button
   id="theme-toggle"
   type="button"
-  class="inline-flex h-9 w-9 items-center justify-center rounded-full border border-line text-ink-muted transition-colors duration-[--dur-quick] hover:text-ink"
+  class="border-line text-ink-muted hover:text-ink inline-flex h-9 w-9 items-center justify-center rounded-full border transition-colors duration-[--dur-quick]"
   aria-label={d.theme.toLight}
   data-to-light={d.theme.toLight}
   data-to-dark={d.theme.toDark}