Regression alert thresholds reviewed quarterly

Stale alert thresholds turn your regression pipeline into noise. When baselines drift — new features, added dependencies, heavier pages — thresholds set at launch either fire constantly and train the team to ignore them, or sit so loose that real regressions slip past unseen. Both outcomes erode the signal that observability tooling is supposed to provide, and users pay the cost in LCP, TBT, and abandoned sessions the team never hears about.

Put a recurring quarterly review on the calendar and record each pass in a tracked doc so the cadence survives team turnover. Capture the current baseline for each Core Web Vital, the threshold, and the date reviewed. Use a file like docs/performance-baselines.md:

## Q1 2026 Review (2026-03-15)
- LCP: baseline 1.8s, threshold 2.5s
- INP: baseline 180ms, threshold 200ms
- CLS: baseline 0.05, threshold 0.1