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/pages/og/[image].png.ts

@@ -1,5 +1,4 @@
 import type { APIRoute } from 'astro';
-import { readFileSync } from 'node:fs';
 import { resolve } from 'node:path';
 import { Resvg } from '@resvg/resvg-js';
 import { PAGE_IDS, type PageId } from '@i18n/slugMap';
@@ -15,8 +14,9 @@ import { getProfile, getMeta } from '@lib/content';
   Fonts read from the project source (cwd = site/ at build).
 */
 
-const fontBuffers = ['SpaceGrotesk.ttf', 'Inter.ttf', 'JetBrainsMono.ttf'].map((n) =>
-  readFileSync(resolve(process.cwd(), 'src/assets/og-fonts', n)),
+const fontDir = resolve(process.cwd(), 'src/assets/og-fonts');
+const fontFiles = ['SpaceGrotesk.ttf', 'Inter.ttf', 'JetBrainsMono.ttf'].map((n) =>
+  resolve(fontDir, n),
 );
 
 export function getStaticPaths() {
@@ -29,8 +29,7 @@ export function getStaticPaths() {
   return paths;
 }
 
-const esc = (s: string) =>
-  s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+const esc = (s: string) => s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
 
 export const GET: APIRoute = ({ props }) => {
   const { pageId, locale } = props as { pageId: PageId; locale: Locale };
@@ -62,12 +61,12 @@ export const GET: APIRoute = ({ props }) => {
 
   const png = new Resvg(svg, {
     fitTo: { mode: 'width', value: 1200 },
-    font: { fontBuffers, loadSystemFonts: false, defaultFontFamily: 'Inter' },
+    font: { fontFiles, loadSystemFonts: false, defaultFontFamily: 'Inter' },
   })
     .render()
     .asPng();
 
-  return new Response(png, {
+  return new Response(new Uint8Array(png), {
     headers: {
       'Content-Type': 'image/png',
       'Cache-Control': 'public, max-age=31536000, immutable',