feat(workflow): MWPW-161458 - Add Core Web Vitals monitoring to PR pipeline #198

[sanrai]

Changes

• Added new GitHub workflow job run-web-vitals-checks to monitor Core Web Vitals metrics during PR deployments
• Implemented comprehensive user interaction simulation for accurate performance measurement
• Added automatic testing of LCP, FID, CLS, FCP, and TTFB metrics against industry standard thresholds
• Updated endpoint URL from chimera runtime to www.adobe.com/chimera-api
• Added puppeteer dependency for browser automation
• Measures LCP, FID, and CLS using Google's recommended 4G throttling
• Supports both desktop and mobile testing environments
• Implements statistical baseline tracking using t-tests
• Maintains rolling 15-sample baseline for performance metrics
• Auto-detects significant regressions and improvements
• Graceful fallback for network conditions
• Detailed performance reporting with statistical significance

Testing

• The workflow runs automatically after deployment
• Metrics are measured against the following thresholds:
  • LCP (Largest Contentful Paint): < 2.5s
  • FID (First Input Delay): < 100ms
  • CLS (Cumulative Layout Shift): < 0.1
  • FCP (First Contentful Paint): < 1.8s
  • TTFB (Time to First Byte): < 800ms

How to use

node web-vitals-check.js <url> --init-baseline

Then

node web-vitals-check.js <url>

Related Issue

[MWPW-161458]