auto-claude: subtask-1-1 - Install Playwright and playwright-lighthouse dependencies

Added testing infrastructure dependencies:
- @playwright/test@^1.58.0 for end-to-end testing
- playwright-lighthouse@^4.0.0 for Lighthouse performance audits

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -14,7 +14,6 @@
     "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
-    "openai": "^4.77.0",
     "@mdx-js/loader": "^3.1.0",
     "@mdx-js/mdx": "^3.1.0",
     "@mdx-js/react": "^3.1.0",
@@ -29,6 +28,7 @@
     "next": "^15.1.0",
     "next-intl": "^3.26.0",
     "next-mdx-remote": "^5.0.0",
+    "openai": "^4.77.0",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "react-intersection-observer": "^9.8.1",
@@ -37,6 +37,7 @@
     "web-vitals": "^5.1.0"
   },
   "devDependencies": {
+    "@playwright/test": "^1.58.0",
     "@tailwindcss/forms": "^0.5.7",
     "@types/mdx": "^2.0.13",
     "@types/node": "^22.0.0",
@@ -45,6 +46,7 @@
     "autoprefixer": "^10.4.18",
     "eslint": "^9.9.1",
     "eslint-config-next": "^15.1.0",
+    "playwright-lighthouse": "^4.0.0",
     "postcss": "^8.4.35",
     "sharp": "^0.34.3",
     "tailwindcss": "^3.4.1",