Skill: Performance Step 0: is the kit here? This skill reads files from the kit. Check once: On only the skill folders were installed, which is what does. Say so plainly, point the user at or the plugin install, and stop. Do not guess the contents of a file you could not open. Make the UI fast and stable. Treat performance as an accessibility concern: slow/janky UIs fail low-end devices first. Steps 1. Read (Core Web Vitals targets, loading strategy, layout-shift, animation perf, design-system runtime cost). 2. Diagnose against budgets: LCP ≤ 2.5s , INP ≤ 200ms , CLS ≤ 0.1 . Measure on a mid-…