test: setup Vitest workspace and Playwright with first nutrition tests

Vitest:
- Workspace at root (vitest.workspace.ts) running per-package configs
- packages/shared/vitest.config.ts with v8 coverage and 70% thresholds
- Root scripts: test / test:watch / test:coverage

Nutrition module in @ketopath/shared:
- calculateBmr (Mifflin-St Jeor) + calculateTdee with activity multipliers
- ACTIVITY_MULTIPLIERS constants matching CLAUDE.md domain knowledge
- 14 unit tests covering Michele/Laura PRD personas, all sex variants,
  every activity level, and input validation (100% coverage on src/nutrition)

Playwright in apps/web:
- chromium-only project, webServer auto-boot of pnpm dev
- e2e/home.spec.ts smoke test asserts Italian copy and disclaimer

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/.gitignore

@@ -3,3 +3,7 @@ out/
 next-env.d.ts.bak
 .vercel/
 *.tsbuildinfo
+test-results/
+playwright-report/
+playwright/.cache/
+blob-report/

apps/web/e2e/home.spec.ts

@@ -0,0 +1,11 @@
+import { expect, test } from '@playwright/test';
+
+test('home page renders Italian copy and CTAs', async ({ page }) => {
+  await page.goto('/');
+
+  await expect(page).toHaveTitle(/KetoPath/);
+  await expect(page.getByRole('heading', { name: 'KetoPath' })).toBeVisible();
+  await expect(page.getByRole('button', { name: 'Inizia gratis' })).toBeVisible();
+  await expect(page.getByRole('button', { name: 'Scopri come funziona' })).toBeVisible();
+  await expect(page.getByText(/non sostituiscono il parere di un medico/)).toBeVisible();
+});

apps/web/package.json

@@ -7,7 +7,8 @@
     "build": "next build",
     "start": "next start --port 3000",
     "typecheck": "tsc --noEmit",
-    "lint": "next lint --max-warnings=0"
+    "lint": "next lint --max-warnings=0",
+    "test:e2e": "playwright test"
   },
   "dependencies": {
     "@ketopath/shared": "workspace:*",
@@ -26,6 +27,7 @@
     "autoprefixer": "^10.4.19",
     "eslint-config-next": "^14.2.5",
     "postcss": "^8.4.39",
-    "tailwindcss": "^3.4.4"
+    "tailwindcss": "^3.4.4",
+    "@playwright/test": "^1.45.3"
   }
 }

apps/web/playwright.config.ts

@@ -0,0 +1,24 @@
+import { defineConfig, devices } from '@playwright/test';
+
+const PORT = 3000;
+const baseURL = `http://localhost:${PORT}`;
+
+export default defineConfig({
+  testDir: './e2e',
+  fullyParallel: true,
+  forbidOnly: Boolean(process.env.CI),
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: process.env.CI ? 'github' : 'list',
+  use: {
+    baseURL,
+    trace: 'on-first-retry',
+  },
+  projects: [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }],
+  webServer: {
+    command: 'pnpm dev',
+    url: baseURL,
+    reuseExistingServer: !process.env.CI,
+    timeout: 120_000,
+  },
+});