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>

tests/playwright.config.ts

@@ -0,0 +1,24 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/*
+  E2E runs against the built static output served by `astro preview` (TECH_SPEC §9.3).
+  The relay is not required — the form spec mocks /api/contact.
+*/
+export default defineConfig({
+  testDir: './e2e',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 1 : 0,
+  reporter: process.env.CI ? [['list'], ['html', { open: 'never' }]] : 'list',
+  use: {
+    baseURL: 'http://localhost:4321',
+    trace: 'on-first-retry',
+  },
+  projects: [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }],
+  webServer: {
+    command: 'pnpm -C ../site build && pnpm -C ../site preview --port 4321 --host',
+    url: 'http://localhost:4321/',
+    timeout: 180_000,
+    reuseExistingServer: !process.env.CI,
+  },
+});