impeccable-posttooluse-hook-zero-llm-cost-scanner

The impeccable npm package provides a 3,590-line JS deterministic design quality engine with 25 rules (13 AI-slop tells + 12 general quality) that runs at zero LLM token cost. It can be wired as a PostToolUse hook on Write/Edit to .html/.css/.tsx/.jsx/.svelte/.astro files via npx impeccable detect --json <file> to surface violations inline automatically. This fills the gap where all current quality assessment is LLM-based, adding a deterministic verification layer that catches what LLMs miss.