fix: Resolve frontend Docker build issues

- Add missing nginx configuration for frontend container
- Add ajv dependency to fix react-scripts build error
- Configure npm to use legacy-peer-deps in Dockerfile
- Create frontend .dockerignore file
- Fix TypeScript peer dependency conflicts

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/package.json

@@ -12,6 +12,7 @@
     "@types/node": "^20.10.7",
     "@types/react": "^18.2.47",
     "@types/react-dom": "^18.2.18",
+    "ajv": "^8.12.0",
     "axios": "^1.6.5",
     "chart.js": "^4.4.1",
     "date-fns": "^3.2.0",