✨ feat(frontend): scaffold minimal Nuxt 3 frontend with healthz dashboard

First step toward a Vue 3 / Nuxt 3 / Playwright e2e frontend stack.

Adds:
- frontend/ - Nuxt 3 scaffold (TypeScript)
- frontend/components/HealthDashboard.vue - calls /api/healthz, shows status/version/uptime/timestamp
- frontend/pages/index.vue - landing page using HealthDashboard
- frontend/nuxt.config.ts - dev proxy /api -> http://localhost:8080
- frontend/playwright.config.ts + tests/e2e/health.spec.ts - 1 baseline e2e test
- .gitignore - frontend artifacts excluded

Out of scope (separate PRs):
- Storybook
- Design system / Tailwind
- Auth pages
- Production build / deploy config

Generated ~95% in autonomy by Mistral Vibe via ICM workspace
~/Work/Vibe/workspaces/frontend-nuxt-scaffold/.

Trainer (Claude) finalized commit/PR (Mistral hit max-turns or trainer takeover).

🤖 Co-Authored-By: Mistral Vibe (devstral-2 / mistral-medium-3.5)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/playwright.config.ts

@@ -0,0 +1,14 @@
+import { defineConfig } from '@playwright/test'
+export default defineConfig({
+  testDir: './tests/e2e',
+  timeout: 30_000,
+  use: {
+    baseURL: 'http://localhost:3000',
+  },
+  webServer: {
+    command: 'npm run dev',
+    url: 'http://localhost:3000',
+    timeout: 60_000,
+    reuseExistingServer: !process.env.CI,
+  },
+})