feat(marketing): add contact form submission and testing setup

- Add contact API endpoint for demo requests and sales enquiries
- Implement functional contact forms on Demo and Pricing pages with honeypot spam protection
- Update footer layout: remove Company section, add contact email
- Update self-hosted FAQ to mention open source with GitHub links
- Add vitest and testing-library dependencies
- Add tests for MarketingLayout and PricingPage components
- Remove placeholder external-auth test file

package.json

@@ -46,6 +46,7 @@
     "date-fns": "^3.6.0",
     "embla-carousel-react": "^8.6.0",
     "input-otp": "^1.4.2",
+    "jsdom": "^27.0.1",
     "lucide-react": "^0.462.0",
     "next-themes": "^0.3.0",
     "react": "^18.3.1",
@@ -64,10 +65,13 @@
   "devDependencies": {
     "@eslint/js": "^9.32.0",
     "@tailwindcss/typography": "^0.5.16",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
     "@types/node": "^22.16.5",
     "@types/react": "^18.3.23",
     "@types/react-dom": "^18.3.7",
     "@vitejs/plugin-react-swc": "^3.11.0",
+    "@vitest/ui": "^3.2.4",
     "autoprefixer": "^10.4.21",
     "eslint": "^9.32.0",
     "eslint-plugin-react-hooks": "^5.2.0",
@@ -78,6 +82,7 @@
     "tailwindcss": "^3.4.17",
     "typescript": "^5.8.3",
     "typescript-eslint": "^8.38.0",
-    "vite": "^5.4.19"
+    "vite": "^5.4.19",
+    "vitest": "^3.2.4"
   }
 }