vrt-regression-watch

What problem does it solve? One-shot visual diffs cannot tell you whether a change made things worse over time. This Skill wires vlmkit's diff agent into a stateful loop that compares each run against the previous run's persisted summary and raises a binary regression signal for CI gates. ## Core Features & Use Cases - Stateful regression detection: Persists per-viewport diff ratios to a JSON summary and emits a ⚠ REGRESSION banner when the majority of viewports get worse. - CI gate integration: Supports --fail-on-regression to exit 1 on regression, with patterns for per-PR GitHub Actions workflows and cached baselines. - Flexible state strategies: Local-rolling (compare against last run) or branch-stable (compare against a fixed main reference) retention modes via --previous and --persist-summary. - Use Case: A team adds a GitHub Actions job that restores main's cached baseline, diffs the PR's rendered pages, and fails the build with a Markdown PR comment whenever the majority of viewports regress. ## Quick Start Ask the agent to set up a recurring vlmkit diff loop that compares each run against the previous summary and fails CI when a visual regression is detected.